java.lang.Object
- org.apache.commons.text.StringSubstitutor

```
public class StringSubstitutor
extends java.lang.Object
```
Substitutes variables within a string by values.
This class takes a piece of text and substitutes all the variables within it. The default definition of a variable is ${variableName}. The prefix and suffix can be changed via constructors and set methods.

Variable values are typically resolved from a map, but could also be resolved from system properties, or by supplying a custom variable resolver.

Using System Properties

The simplest example is to use this class to replace Java System properties. For example:
```
 StringSubstitutor
     .replaceSystemProperties("You are running with java.version = ${java.version} and os.name = ${os.name}.");
 
```
Using a Custom Map

Typical usage of this class follows the following pattern:
- Create and initialize a StringSubstitutor with the map that contains the values for the variables you want to make available.
- Optionally set attributes like variable prefix, variable suffix, default value delimiter, and so on.
- Call the replace() method with in the source text for interpolation.
- The returned text contains all variable references (as long as their values are known) as resolved.
For example:
```
 // Build map
 Map<String, String> valuesMap = new HashMap<>();
 valuesMap.put("animal", "quick brown fox");
 valuesMap.put("target", "lazy dog");
 String templateString = "The ${animal} jumped over the ${target}.";

 // Build StringSubstitutor
 StringSubstitutor sub = new StringSubstitutor(valuesMap);

 // Replace
 String resolvedString = sub.replace(templateString);
 
```
yielding:
```
 "The quick brown fox jumped over the lazy dog."
 
```
Providing Default Values

You can set a default value for unresolved variables. The default value for a variable can be appended to the variable name after the variable default value delimiter. The default value of the variable default value delimiter is ":-", as in bash and other *nix shells.

You can set the variable value delimiter with setValueDelimiterMatcher(StringMatcher), setValueDelimiter(char) or setValueDelimiter(String).

For example:
```
 // Build map
 Map<String, String> valuesMap = new HashMap<>();
 valuesMap.put("animal", "quick brown fox");
 valuesMap.put("target", "lazy dog");
 String templateString = "The ${animal} jumped over the ${target} ${undefined.number:-1234567890} times.";

 // Build StringSubstitutor
 StringSubstitutor sub = new StringSubstitutor(valuesMap);

 // Replace
 String resolvedString = sub.replace(templateString);
 
```
yielding:
```
 "The quick brown fox jumped over the lazy dog 1234567890 times."
 
```
StringSubstitutor supports throwing exceptions for unresolved variables, you enable this by setting calling setEnableUndefinedVariableException(boolean) with true.

Reusing Instances

Static shortcut methods cover the most common use cases. If multiple replace operations are to be performed, creating and reusing an instance of this class will be more efficient.

Using Interpolation

The default interpolator lets you use string lookups like:
```
 final StringSubstitutor interpolator = StringSubstitutor.createInterpolator();
 final String text = interpolator.replace(
       "Base64 Decoder:        ${base64Decoder:SGVsbG9Xb3JsZCE=}\n"
     + "Base64 Encoder:        ${base64Encoder:HelloWorld!}\n"
     + "Java Constant:         ${const:java.awt.event.KeyEvent.VK_ESCAPE}\n"
     + "Date:                  ${date:yyyy-MM-dd}\n"
     + "Environment Variable:  ${env:USERNAME}\n"
     + "File Content:          ${file:UTF-8:src/test/resources/document.properties}\n"
     + "Java:                  ${java:version}\n"
     + "Localhost:             ${localhost:canonical-name}\n"
     + "Properties File:       ${properties:src/test/resources/document.properties::mykey}\n"
     + "Resource Bundle:       ${resourceBundle:org.apache.commons.text.example.testResourceBundleLookup:mykey}\n"
     + "System Property:       ${sys:user.dir}\n"
     + "URL Decoder:           ${urlDecoder:Hello%20World%21}\n"
     + "URL Encoder:           ${urlEncoder:Hello World!}\n"
     + "XML XPath:             ${xml:src/test/resources/document.xml:/root/path/to/node}\n");
 
```
For documentation and a full list of available lookups, see StringLookupFactory.

NOTE: The list of lookups available by default in createInterpolator() changed in version 1.10.0. See the StringLookupFactory documentation for details and an explanation on how to reproduce the previous functionality.

Using Recursive Variable Replacement

Variable replacement can work recursively by calling setEnableSubstitutionInVariables(boolean) with true. If a variable value contains a variable then that variable will also be replaced. Cyclic replacements are detected and will throw an exception.

You can get the replace result to contain a variable prefix. For example:
```
 "The variable ${${name}} must be used."
 
```
If the value of the "name" variable is "x", then only the variable "name" is replaced resulting in:
```
 "The variable ${x} must be used."
 
```
To achieve this effect there are two possibilities: Either set a different prefix and suffix for variables which do not conflict with the result text you want to produce. The other possibility is to use the escape character, by default '$'. If this character is placed before a variable reference, this reference is ignored and won't be replaced. For example:
```
 "The variable $${${name}} must be used."
 
```
In some complex scenarios you might even want to perform substitution in the names of variables, for instance
```
 ${jre-${java.specification.version}}
 
```
StringSubstitutor supports this recursive substitution in variable names, but it has to be enabled explicitly by calling setEnableSubstitutionInVariables(boolean) with true.

Thread Safety

This class is not thread safe.
Since:

1.3

Field Summary

Fields
Modifier and Type	Field	Description
`static char`	`DEFAULT_ESCAPE`	Constant for the default escape character.
`static StringMatcher`	`DEFAULT_PREFIX`	Constant for the default variable prefix.
`static StringMatcher`	`DEFAULT_SUFFIX`	Constant for the default variable suffix.
`static StringMatcher`	`DEFAULT_VALUE_DELIMITER`	Constant for the default value delimiter of a variable.
`static java.lang.String`	`DEFAULT_VAR_DEFAULT`	The default variable default separator.
`static java.lang.String`	`DEFAULT_VAR_END`	The default variable end separator.
`static java.lang.String`	`DEFAULT_VAR_START`	The default variable start separator.

Constructor Summary

Constructors
Constructor	Description
`StringSubstitutor()`	Creates a new instance with defaults for variable prefix and suffix and the escaping character.
`StringSubstitutor(java.util.Map<java.lang.String,V> valueMap)`	Creates a new instance and initializes it.
`StringSubstitutor(java.util.Map<java.lang.String,V> valueMap, java.lang.String prefix, java.lang.String suffix)`	Creates a new instance and initializes it.
`StringSubstitutor(java.util.Map<java.lang.String,V> valueMap, java.lang.String prefix, java.lang.String suffix, char escape)`	Creates a new instance and initializes it.
`StringSubstitutor(java.util.Map<java.lang.String,V> valueMap, java.lang.String prefix, java.lang.String suffix, char escape, java.lang.String valueDelimiter)`	Creates a new instance and initializes it.
`StringSubstitutor(StringLookup variableResolver)`	Creates a new instance and initializes it.
`StringSubstitutor(StringLookup variableResolver, java.lang.String prefix, java.lang.String suffix, char escape)`	Creates a new instance and initializes it.
`StringSubstitutor(StringLookup variableResolver, java.lang.String prefix, java.lang.String suffix, char escape, java.lang.String valueDelimiter)`	Creates a new instance and initializes it.
`StringSubstitutor(StringLookup variableResolver, StringMatcher prefixMatcher, StringMatcher suffixMatcher, char escape)`	Creates a new instance and initializes it.
`StringSubstitutor(StringLookup variableResolver, StringMatcher prefixMatcher, StringMatcher suffixMatcher, char escape, StringMatcher valueDelimiterMatcher)`	Creates a new instance and initializes it.
`StringSubstitutor(StringSubstitutor other)`	Creates a new instance based on the given StringSubstitutor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static StringSubstitutor`	`createInterpolator()`	Creates a new instance using the interpolator string lookup `StringLookupFactory.interpolatorStringLookup()`.
`char`	`getEscapeChar()`	Returns the escape character.
`StringLookup`	`getStringLookup()`	Gets the StringLookup that is used to lookup variables.
`StringMatcher`	`getValueDelimiterMatcher()`	Gets the variable default value delimiter matcher currently in use.
`StringMatcher`	`getVariablePrefixMatcher()`	Gets the variable prefix matcher currently in use.
`StringMatcher`	`getVariableSuffixMatcher()`	Gets the variable suffix matcher currently in use.
`boolean`	`isDisableSubstitutionInValues()`	Returns a flag whether substitution is disabled in variable values.If set to true, the values of variables can contain other variables will not be processed and substituted original variable is evaluated, e.g.
`boolean`	`isEnableSubstitutionInVariables()`	Returns a flag whether substitution is done in variable names.
`boolean`	`isEnableUndefinedVariableException()`	Returns a flag whether exception can be thrown upon undefined variable.
`boolean`	`isPreserveEscapes()`	Returns the flag controlling whether escapes are preserved during substitution.
`java.lang.String`	`replace(char[] source)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source array as a template.
`java.lang.String`	`replace(char[] source, int offset, int length)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source array as a template.
`java.lang.String`	`replace(java.lang.CharSequence source)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source as a template.
`java.lang.String`	`replace(java.lang.CharSequence source, int offset, int length)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source as a template.
`java.lang.String`	`replace(java.lang.Object source)`	Replaces all the occurrences of variables in the given source object with their matching values from the resolver.
`static <V> java.lang.String`	`replace(java.lang.Object source, java.util.Map<java.lang.String,V> valueMap)`	Replaces all the occurrences of variables in the given source object with their matching values from the map.
`static <V> java.lang.String`	`replace(java.lang.Object source, java.util.Map<java.lang.String,V> valueMap, java.lang.String prefix, java.lang.String suffix)`	Replaces all the occurrences of variables in the given source object with their matching values from the map.
`static java.lang.String`	`replace(java.lang.Object source, java.util.Properties valueProperties)`	Replaces all the occurrences of variables in the given source object with their matching values from the properties.
`java.lang.String`	`replace(java.lang.String source)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source string as a template.
`java.lang.String`	`replace(java.lang.StringBuffer source)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source buffer as a template.
`java.lang.String`	`replace(java.lang.StringBuffer source, int offset, int length)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source buffer as a template.
`java.lang.String`	`replace(java.lang.String source, int offset, int length)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source string as a template.
`java.lang.String`	`replace(TextStringBuilder source)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source builder as a template.
`java.lang.String`	`replace(TextStringBuilder source, int offset, int length)`	Replaces all the occurrences of variables with their matching values from the resolver using the given source builder as a template.
`boolean`	`replaceIn(java.lang.StringBuffer source)`	Replaces all the occurrences of variables within the given source buffer with their matching values from the resolver.
`boolean`	`replaceIn(java.lang.StringBuffer source, int offset, int length)`	Replaces all the occurrences of variables within the given source buffer with their matching values from the resolver.
`boolean`	`replaceIn(java.lang.StringBuilder source)`	Replaces all the occurrences of variables within the given source buffer with their matching values from the resolver.
`boolean`	`replaceIn(java.lang.StringBuilder source, int offset, int length)`	Replaces all the occurrences of variables within the given source builder with their matching values from the resolver.
`boolean`	`replaceIn(TextStringBuilder source)`	Replaces all the occurrences of variables within the given source builder with their matching values from the resolver.
`boolean`	`replaceIn(TextStringBuilder source, int offset, int length)`	Replaces all the occurrences of variables within the given source builder with their matching values from the resolver.
`static java.lang.String`	`replaceSystemProperties(java.lang.Object source)`	Replaces all the occurrences of variables in the given source object with their matching values from the system properties.
`StringSubstitutor`	`setDisableSubstitutionInValues(boolean disableSubstitutionInValues)`	Sets a flag whether substitution is done in variable values (recursive).
`StringSubstitutor`	`setEnableSubstitutionInVariables(boolean enableSubstitutionInVariables)`	Sets a flag whether substitution is done in variable names.
`StringSubstitutor`	`setEnableUndefinedVariableException(boolean failOnUndefinedVariable)`	Sets a flag whether exception should be thrown if any variable is undefined.
`StringSubstitutor`	`setEscapeChar(char escapeCharacter)`	Sets the escape character.
`StringSubstitutor`	`setPreserveEscapes(boolean preserveEscapes)`	Sets a flag controlling whether escapes are preserved during substitution.
`StringSubstitutor`	`setValueDelimiter(char valueDelimiter)`	Sets the variable default value delimiter to use.
`StringSubstitutor`	`setValueDelimiter(java.lang.String valueDelimiter)`	Sets the variable default value delimiter to use.
`StringSubstitutor`	`setValueDelimiterMatcher(StringMatcher valueDelimiterMatcher)`	Sets the variable default value delimiter matcher to use.
`StringSubstitutor`	`setVariablePrefix(char prefix)`	Sets the variable prefix to use.
`StringSubstitutor`	`setVariablePrefix(java.lang.String prefix)`	Sets the variable prefix to use.
`StringSubstitutor`	`setVariablePrefixMatcher(StringMatcher prefixMatcher)`	Sets the variable prefix matcher currently in use.
`StringSubstitutor`	`setVariableResolver(StringLookup variableResolver)`	Sets the VariableResolver that is used to lookup variables.
`StringSubstitutor`	`setVariableSuffix(char suffix)`	Sets the variable suffix to use.
`StringSubstitutor`	`setVariableSuffix(java.lang.String suffix)`	Sets the variable suffix to use.
`StringSubstitutor`	`setVariableSuffixMatcher(StringMatcher suffixMatcher)`	Sets the variable suffix matcher currently in use.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail
- DEFAULT_ESCAPE
```
public static final char DEFAULT_ESCAPE
```
  Constant for the default escape character.
  
  See Also:
  
  Constant Field Values
- DEFAULT_VAR_DEFAULT
```
public static final java.lang.String DEFAULT_VAR_DEFAULT
```
  The default variable default separator.
  
  Since:
  
  1.5.
  
  See Also:
  
  Constant Field Values
- DEFAULT_VAR_END
```
public static final java.lang.String DEFAULT_VAR_END
```
  The default variable end separator.
  
  Since:
  
  1.5.
  
  See Also:
  
  Constant Field Values
- DEFAULT_VAR_START
```
public static final java.lang.String DEFAULT_VAR_START
```
  The default variable start separator.
  
  Since:
  
  1.5.
  
  See Also:
  
  Constant Field Values
- DEFAULT_PREFIX
```
public static final StringMatcher DEFAULT_PREFIX
```
  Constant for the default variable prefix.
- DEFAULT_SUFFIX
```
public static final StringMatcher DEFAULT_SUFFIX
```
  Constant for the default variable suffix.
- DEFAULT_VALUE_DELIMITER
```
public static final StringMatcher DEFAULT_VALUE_DELIMITER
```
  Constant for the default value delimiter of a variable.

Constructor Detail
- StringSubstitutor
```
public StringSubstitutor()
```
  Creates a new instance with defaults for variable prefix and suffix and the escaping character.
- StringSubstitutor
```
public StringSubstitutor(java.util.Map<java.lang.String,V> valueMap)
```
  Creates a new instance and initializes it. Uses defaults for variable prefix and suffix and the escaping character.
  
  Type Parameters:
  
  V - the type of the values in the map
  
  Parameters:
  
  valueMap - the map with the variables' values, may be null
- StringSubstitutor
```
public StringSubstitutor(java.util.Map<java.lang.String,V> valueMap,
                         java.lang.String prefix,
                         java.lang.String suffix)
```
  Creates a new instance and initializes it. Uses a default escaping character.
  
  Type Parameters:
  
  V - the type of the values in the map
  
  Parameters:
  
  valueMap - the map with the variables' values, may be null
  
  prefix - the prefix for variables, not null
  
  suffix - the suffix for variables, not null
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(java.util.Map<java.lang.String,V> valueMap,
                         java.lang.String prefix,
                         java.lang.String suffix,
                         char escape)
```
  Creates a new instance and initializes it.
  
  Type Parameters:
  
  V - the type of the values in the map
  
  Parameters:
  
  valueMap - the map with the variables' values, may be null
  
  prefix - the prefix for variables, not null
  
  suffix - the suffix for variables, not null
  
  escape - the escape character
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(java.util.Map<java.lang.String,V> valueMap,
                         java.lang.String prefix,
                         java.lang.String suffix,
                         char escape,
                         java.lang.String valueDelimiter)
```
  Creates a new instance and initializes it.
  
  Type Parameters:
  
  V - the type of the values in the map
  
  Parameters:
  
  valueMap - the map with the variables' values, may be null
  
  prefix - the prefix for variables, not null
  
  suffix - the suffix for variables, not null
  
  escape - the escape character
  
  valueDelimiter - the variable default value delimiter, may be null
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(StringLookup variableResolver)
```
  Creates a new instance and initializes it.
  
  Parameters:
  
  variableResolver - the variable resolver, may be null
- StringSubstitutor
```
public StringSubstitutor(StringLookup variableResolver,
                         java.lang.String prefix,
                         java.lang.String suffix,
                         char escape)
```
  Creates a new instance and initializes it.
  
  Parameters:
  
  variableResolver - the variable resolver, may be null
  
  prefix - the prefix for variables, not null
  
  suffix - the suffix for variables, not null
  
  escape - the escape character
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(StringLookup variableResolver,
                         java.lang.String prefix,
                         java.lang.String suffix,
                         char escape,
                         java.lang.String valueDelimiter)
```
  Creates a new instance and initializes it.
  
  Parameters:
  
  variableResolver - the variable resolver, may be null
  
  prefix - the prefix for variables, not null
  
  suffix - the suffix for variables, not null
  
  escape - the escape character
  
  valueDelimiter - the variable default value delimiter string, may be null
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(StringLookup variableResolver,
                         StringMatcher prefixMatcher,
                         StringMatcher suffixMatcher,
                         char escape)
```
  Creates a new instance and initializes it.
  
  Parameters:
  
  variableResolver - the variable resolver, may be null
  
  prefixMatcher - the prefix for variables, not null
  
  suffixMatcher - the suffix for variables, not null
  
  escape - the escape character
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(StringLookup variableResolver,
                         StringMatcher prefixMatcher,
                         StringMatcher suffixMatcher,
                         char escape,
                         StringMatcher valueDelimiterMatcher)
```
  Creates a new instance and initializes it.
  
  Parameters:
  
  variableResolver - the variable resolver, may be null
  
  prefixMatcher - the prefix for variables, not null
  
  suffixMatcher - the suffix for variables, not null
  
  escape - the escape character
  
  valueDelimiterMatcher - the variable default value delimiter matcher, may be null
  
  Throws:
  
  java.lang.IllegalArgumentException - if the prefix or suffix is null
- StringSubstitutor
```
public StringSubstitutor(StringSubstitutor other)
```
  Creates a new instance based on the given StringSubstitutor.
  
  Parameters:
  
  other - The StringSubstitutor used as the source.
  
  Since:
  
  1.9

Method Detail

createInterpolator

public static StringSubstitutor createInterpolator()

Creates a new instance using the interpolator string lookup StringLookupFactory.interpolatorStringLookup().

This StringSubstitutor lets you perform substitutions like:

 StringSubstitutor.createInterpolator().replace(
   "OS name: ${sys:os.name}, user: ${env:USER}");

The table below lists the lookups available by default in the returned instance. These may be modified through the use of the "org.apache.commons.text.lookup.StringLookupFactory.defaultStringLookups" system property, as described in the StringLookupFactory documentation.

NOTE: The list of lookups available by default changed in version 1.10.0. Configuration via system property (as mentioned above) may be necessary to reproduce previous functionality.

Default Lookups
Key	Lookup
"base64Decoder"	`StringLookupFactory.base64DecoderStringLookup()`
"base64Encoder"	`StringLookupFactory.base64EncoderStringLookup()`
"const"	`StringLookupFactory.constantStringLookup()`
"date"	`StringLookupFactory.dateStringLookup()`
"env"	`StringLookupFactory.environmentVariableStringLookup()`
"file"	`StringLookupFactory.fileStringLookup()`
"java"	`StringLookupFactory.javaPlatformStringLookup()`
"localhost"	`StringLookupFactory.localHostStringLookup()`
"properties"	`StringLookupFactory.propertiesStringLookup()`
"resourceBundle"	`StringLookupFactory.resourceBundleStringLookup()`
"sys"	`StringLookupFactory.systemPropertyStringLookup()`
"urlDecoder"	`StringLookupFactory.urlDecoderStringLookup()`
"urlEncoder"	`StringLookupFactory.urlEncoderStringLookup()`
"xml"	`StringLookupFactory.xmlStringLookup()`

Returns:: a new instance using the interpolator string lookup.
Since:: 1.8
See Also:: StringLookupFactory.interpolatorStringLookup()

replace
```
public static <V> java.lang.String replace(java.lang.Object source,
                                           java.util.Map<java.lang.String,V> valueMap)
```
Replaces all the occurrences of variables in the given source object with their matching values from the map.

Type Parameters:

V - the type of the values in the map

Parameters:

source - the source text containing the variables to substitute, null returns null

valueMap - the map with the values, may be null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if a variable is not found and enableUndefinedVariableException is true

replace
```
public static <V> java.lang.String replace(java.lang.Object source,
                                           java.util.Map<java.lang.String,V> valueMap,
                                           java.lang.String prefix,
                                           java.lang.String suffix)
```
Replaces all the occurrences of variables in the given source object with their matching values from the map. This method allows to specify a custom variable prefix and suffix

Type Parameters:

V - the type of the values in the map

Parameters:

source - the source text containing the variables to substitute, null returns null

valueMap - the map with the values, may be null

prefix - the prefix of variables, not null

suffix - the suffix of variables, not null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if the prefix or suffix is null

java.lang.IllegalArgumentException - if a variable is not found and enableUndefinedVariableException is true

replace
```
public static java.lang.String replace(java.lang.Object source,
                                       java.util.Properties valueProperties)
```
Replaces all the occurrences of variables in the given source object with their matching values from the properties.

Parameters:

source - the source text containing the variables to substitute, null returns null

valueProperties - the properties with values, may be null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if a variable is not found and enableUndefinedVariableException is true

replaceSystemProperties
```
public static java.lang.String replaceSystemProperties(java.lang.Object source)
```
Replaces all the occurrences of variables in the given source object with their matching values from the system properties.

Parameters:

source - the source text containing the variables to substitute, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if a variable is not found and enableUndefinedVariableException is true

getEscapeChar
```
public char getEscapeChar()
```
Returns the escape character.

Returns:

The character used for escaping variable references

getStringLookup
```
public StringLookup getStringLookup()
```
Gets the StringLookup that is used to lookup variables.

Returns:

The StringLookup

getValueDelimiterMatcher
```
public StringMatcher getValueDelimiterMatcher()
```
Gets the variable default value delimiter matcher currently in use.
The variable default value delimiter is the character or characters that delimit the variable name and the variable default value. This delimiter is expressed in terms of a matcher allowing advanced variable default value delimiter matches.

If it returns null, then the variable default value resolution is disabled.

Returns:

The variable default value delimiter matcher in use, may be null

getVariablePrefixMatcher
```
public StringMatcher getVariablePrefixMatcher()
```
Gets the variable prefix matcher currently in use.
The variable prefix is the character or characters that identify the start of a variable. This prefix is expressed in terms of a matcher allowing advanced prefix matches.

Returns:

The prefix matcher in use

getVariableSuffixMatcher
```
public StringMatcher getVariableSuffixMatcher()
```
Gets the variable suffix matcher currently in use.
The variable suffix is the character or characters that identify the end of a variable. This suffix is expressed in terms of a matcher allowing advanced suffix matches.

Returns:

The suffix matcher in use

isDisableSubstitutionInValues

public boolean isDisableSubstitutionInValues()

Returns a flag whether substitution is disabled in variable values.If set to true, the values of variables can contain other variables will not be processed and substituted original variable is evaluated, e.g.

 Map<String, String> valuesMap = new HashMap<>();
 valuesMap.put("name", "Douglas ${surname}");
 valuesMap.put("surname", "Crockford");
 String templateString = "Hi ${name}";
 StrSubstitutor sub = new StrSubstitutor(valuesMap);
 String resolvedString = sub.replace(templateString);

yielding:

      Hi Douglas ${surname}

Returns:: The substitution in variable values flag

isEnableSubstitutionInVariables
```
public boolean isEnableSubstitutionInVariables()
```
Returns a flag whether substitution is done in variable names.

Returns:

The substitution in variable names flag

isEnableUndefinedVariableException
```
public boolean isEnableUndefinedVariableException()
```
Returns a flag whether exception can be thrown upon undefined variable.

Returns:

The fail on undefined variable flag

isPreserveEscapes
```
public boolean isPreserveEscapes()
```
Returns the flag controlling whether escapes are preserved during substitution.

Returns:

The preserve escape flag

replace
```
public java.lang.String replace(char[] source)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source array as a template. The array is not altered by this method.

Parameters:

source - the character array to replace in, not altered, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(char[] source,
                                int offset,
                                int length)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source array as a template. The array is not altered by this method.
Only the specified portion of the array will be processed. The rest of the array is not processed, and is not returned.

Parameters:

source - the character array to replace in, not altered, null returns null

offset - the start offset within the array, must be valid

length - the length within the array to be processed, must be valid

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

java.lang.StringIndexOutOfBoundsException - if offset is not in the range 0 <= offset <= chars.length

java.lang.StringIndexOutOfBoundsException - if length < 0

java.lang.StringIndexOutOfBoundsException - if offset + length > chars.length

replace
```
public java.lang.String replace(java.lang.CharSequence source)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source as a template. The source is not altered by this method.

Parameters:

source - the buffer to use as a template, not changed, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(java.lang.CharSequence source,
                                int offset,
                                int length)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source as a template. The source is not altered by this method.
Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, and is not returned.

Parameters:

source - the buffer to use as a template, not changed, null returns null

offset - the start offset within the array, must be valid

length - the length within the array to be processed, must be valid

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(java.lang.Object source)
```
Replaces all the occurrences of variables in the given source object with their matching values from the resolver. The input source object is converted to a string using toString and is not altered.

Parameters:

source - the source to replace in, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if a variable is not found and enableUndefinedVariableException is true

replace
```
public java.lang.String replace(java.lang.String source)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source string as a template.

Parameters:

source - the string to replace in, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(java.lang.String source,
                                int offset,
                                int length)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source string as a template.
Only the specified portion of the string will be processed. The rest of the string is not processed, and is not returned.

Parameters:

source - the string to replace in, null returns null

offset - the start offset within the source, must be valid

length - the length within the source to be processed, must be valid

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

java.lang.StringIndexOutOfBoundsException - if offset is not in the range 0 <= offset <= source.length()

java.lang.StringIndexOutOfBoundsException - if length < 0

java.lang.StringIndexOutOfBoundsException - if offset + length > source.length()

replace
```
public java.lang.String replace(java.lang.StringBuffer source)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source buffer as a template. The buffer is not altered by this method.

Parameters:

source - the buffer to use as a template, not changed, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(java.lang.StringBuffer source,
                                int offset,
                                int length)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source buffer as a template. The buffer is not altered by this method.
Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, and is not returned.

Parameters:

source - the buffer to use as a template, not changed, null returns null

offset - the start offset within the source, must be valid

length - the length within the source to be processed, must be valid

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(TextStringBuilder source)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source builder as a template. The builder is not altered by this method.

Parameters:

source - the builder to use as a template, not changed, null returns null

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replace
```
public java.lang.String replace(TextStringBuilder source,
                                int offset,
                                int length)
```
Replaces all the occurrences of variables with their matching values from the resolver using the given source builder as a template. The builder is not altered by this method.
Only the specified portion of the builder will be processed. The rest of the builder is not processed, and is not returned.

Parameters:

source - the builder to use as a template, not changed, null returns null

offset - the start offset within the source, must be valid

length - the length within the source to be processed, must be valid

Returns:

The result of the replace operation

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replaceIn
```
public boolean replaceIn(java.lang.StringBuffer source)
```
Replaces all the occurrences of variables within the given source buffer with their matching values from the resolver. The buffer is updated with the result.

Parameters:

source - the buffer to replace in, updated, null returns zero

Returns:

true if altered

replaceIn
```
public boolean replaceIn(java.lang.StringBuffer source,
                         int offset,
                         int length)
```
Replaces all the occurrences of variables within the given source buffer with their matching values from the resolver. The buffer is updated with the result.
Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, but it is not deleted.

Parameters:

source - the buffer to replace in, updated, null returns zero

offset - the start offset within the source, must be valid

length - the length within the source to be processed, must be valid

Returns:

true if altered

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replaceIn
```
public boolean replaceIn(java.lang.StringBuilder source)
```
Replaces all the occurrences of variables within the given source buffer with their matching values from the resolver. The buffer is updated with the result.

Parameters:

source - the buffer to replace in, updated, null returns zero

Returns:

true if altered

replaceIn
```
public boolean replaceIn(java.lang.StringBuilder source,
                         int offset,
                         int length)
```
Replaces all the occurrences of variables within the given source builder with their matching values from the resolver. The builder is updated with the result.
Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, but it is not deleted.

Parameters:

source - the buffer to replace in, updated, null returns zero

offset - the start offset within the source, must be valid

length - the length within the source to be processed, must be valid

Returns:

true if altered

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replaceIn
```
public boolean replaceIn(TextStringBuilder source)
```
Replaces all the occurrences of variables within the given source builder with their matching values from the resolver.

Parameters:

source - the builder to replace in, updated, null returns zero

Returns:

true if altered

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

replaceIn
```
public boolean replaceIn(TextStringBuilder source,
                         int offset,
                         int length)
```
Replaces all the occurrences of variables within the given source builder with their matching values from the resolver.
Only the specified portion of the builder will be processed. The rest of the builder is not processed, but it is not deleted.

Parameters:

source - the builder to replace in, null returns zero

offset - the start offset within the source, must be valid

length - the length within the source to be processed, must be valid

Returns:

true if altered

Throws:

java.lang.IllegalArgumentException - if variable is not found when its allowed to throw exception

setDisableSubstitutionInValues
```
public StringSubstitutor setDisableSubstitutionInValues(boolean disableSubstitutionInValues)
```
Sets a flag whether substitution is done in variable values (recursive).

Parameters:

disableSubstitutionInValues - true if substitution in variable value are disabled

Returns:

this, to enable chaining

setEnableSubstitutionInVariables
```
public StringSubstitutor setEnableSubstitutionInVariables(boolean enableSubstitutionInVariables)
```
Sets a flag whether substitution is done in variable names. If set to true, the names of variables can contain other variables which are processed first before the original variable is evaluated, e.g. ${jre-${java.version}}. The default value is false.

Parameters:

enableSubstitutionInVariables - the new value of the flag

Returns:

this, to enable chaining

setEnableUndefinedVariableException
```
public StringSubstitutor setEnableUndefinedVariableException(boolean failOnUndefinedVariable)
```
Sets a flag whether exception should be thrown if any variable is undefined.

Parameters:

failOnUndefinedVariable - true if exception should be thrown on undefined variable

Returns:

this, to enable chaining

setEscapeChar
```
public StringSubstitutor setEscapeChar(char escapeCharacter)
```
Sets the escape character. If this character is placed before a variable reference in the source text, this variable will be ignored.

Parameters:

escapeCharacter - the escape character (0 for disabling escaping)

Returns:

this, to enable chaining

setPreserveEscapes
```
public StringSubstitutor setPreserveEscapes(boolean preserveEscapes)
```
Sets a flag controlling whether escapes are preserved during substitution. If set to true, the escape character is retained during substitution (e.g. $${this-is-escaped} remains $${this-is-escaped}). If set to false, the escape character is removed during substitution (e.g. $${this-is-escaped} becomes ${this-is-escaped}). The default value is false

Parameters:

preserveEscapes - true if escapes are to be preserved

Returns:

this, to enable chaining

setValueDelimiter
```
public StringSubstitutor setValueDelimiter(char valueDelimiter)
```
Sets the variable default value delimiter to use.
The variable default value delimiter is the character or characters that delimit the variable name and the variable default value. This method allows a single character variable default value delimiter to be easily set.

Parameters:

valueDelimiter - the variable default value delimiter character to use

Returns:

this, to enable chaining

setValueDelimiter
```
public StringSubstitutor setValueDelimiter(java.lang.String valueDelimiter)
```
Sets the variable default value delimiter to use.
The variable default value delimiter is the character or characters that delimit the variable name and the variable default value. This method allows a string variable default value delimiter to be easily set.

If the valueDelimiter is null or empty string, then the variable default value resolution becomes disabled.

Parameters:

valueDelimiter - the variable default value delimiter string to use, may be null or empty

Returns:

this, to enable chaining

setValueDelimiterMatcher
```
public StringSubstitutor setValueDelimiterMatcher(StringMatcher valueDelimiterMatcher)
```
Sets the variable default value delimiter matcher to use.
The variable default value delimiter is the character or characters that delimit the variable name and the variable default value. This delimiter is expressed in terms of a matcher allowing advanced variable default value delimiter matches.

If the valueDelimiterMatcher is null, then the variable default value resolution becomes disabled.

Parameters:

valueDelimiterMatcher - variable default value delimiter matcher to use, may be null

Returns:

this, to enable chaining

setVariablePrefix
```
public StringSubstitutor setVariablePrefix(char prefix)
```
Sets the variable prefix to use.
The variable prefix is the character or characters that identify the start of a variable. This method allows a single character prefix to be easily set.

Parameters:

prefix - the prefix character to use

Returns:

this, to enable chaining

setVariablePrefix
```
public StringSubstitutor setVariablePrefix(java.lang.String prefix)
```
Sets the variable prefix to use.
The variable prefix is the character or characters that identify the start of a variable. This method allows a string prefix to be easily set.

Parameters:

prefix - the prefix for variables, not null

Returns:

this, to enable chaining

Throws:

java.lang.IllegalArgumentException - if the prefix is null

setVariablePrefixMatcher
```
public StringSubstitutor setVariablePrefixMatcher(StringMatcher prefixMatcher)
```
Sets the variable prefix matcher currently in use.
The variable prefix is the character or characters that identify the start of a variable. This prefix is expressed in terms of a matcher allowing advanced prefix matches.

Parameters:

prefixMatcher - the prefix matcher to use, null ignored

Returns:

this, to enable chaining

Throws:

java.lang.IllegalArgumentException - if the prefix matcher is null

setVariableResolver
```
public StringSubstitutor setVariableResolver(StringLookup variableResolver)
```
Sets the VariableResolver that is used to lookup variables.

Parameters:

variableResolver - the VariableResolver

Returns:

this, to enable chaining

setVariableSuffix
```
public StringSubstitutor setVariableSuffix(char suffix)
```
Sets the variable suffix to use.
The variable suffix is the character or characters that identify the end of a variable. This method allows a single character suffix to be easily set.

Parameters:

suffix - the suffix character to use

Returns:

this, to enable chaining

setVariableSuffix
```
public StringSubstitutor setVariableSuffix(java.lang.String suffix)
```
Sets the variable suffix to use.
The variable suffix is the character or characters that identify the end of a variable. This method allows a string suffix to be easily set.

Parameters:

suffix - the suffix for variables, not null

Returns:

this, to enable chaining

Throws:

java.lang.IllegalArgumentException - if the suffix is null

setVariableSuffixMatcher
```
public StringSubstitutor setVariableSuffixMatcher(StringMatcher suffixMatcher)
```
Sets the variable suffix matcher currently in use.
The variable suffix is the character or characters that identify the end of a variable. This suffix is expressed in terms of a matcher allowing advanced suffix matches.

Parameters:

suffixMatcher - the suffix matcher to use, null ignored

Returns:

this, to enable chaining

Throws:

java.lang.IllegalArgumentException - if the suffix matcher is null

Class StringSubstitutor

Using System Properties

Using a Custom Map

Providing Default Values

Reusing Instances

Using Interpolation

Using Recursive Variable Replacement

Thread Safety

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_ESCAPE

DEFAULT_VAR_DEFAULT

DEFAULT_VAR_END

DEFAULT_VAR_START

DEFAULT_PREFIX

DEFAULT_SUFFIX

DEFAULT_VALUE_DELIMITER

Constructor Detail

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

StringSubstitutor

Method Detail

createInterpolator

replace

replace

replace

replaceSystemProperties

getEscapeChar

getStringLookup

getValueDelimiterMatcher

getVariablePrefixMatcher

getVariableSuffixMatcher

isDisableSubstitutionInValues

isEnableSubstitutionInVariables

isEnableUndefinedVariableException

isPreserveEscapes

replace

replace

replace

replace

replace

replace

replace

replace

replace

replace

replace

replaceIn

replaceIn

replaceIn

replaceIn

replaceIn

replaceIn

setDisableSubstitutionInValues

setEnableSubstitutionInVariables

setEnableUndefinedVariableException

setEscapeChar

setPreserveEscapes

setValueDelimiter

setValueDelimiter

setValueDelimiterMatcher

setVariablePrefix

setVariablePrefix

setVariablePrefixMatcher

setVariableResolver

setVariableSuffix

setVariableSuffix

setVariableSuffixMatcher