Class InefficientEmptyStringCheckRule
- java.lang.Object
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- net.sourceforge.pmd.properties.AbstractPropertySource
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- net.sourceforge.pmd.lang.rule.AbstractRule
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- net.sourceforge.pmd.lang.java.rule.AbstractJavaRule
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- net.sourceforge.pmd.lang.java.rule.performance.InefficientEmptyStringCheckRule
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- All Implemented Interfaces:
JavaParserVisitor
,ImmutableLanguage
,PropertySource
,Rule
public class InefficientEmptyStringCheckRule extends AbstractJavaRule
This rule finds code which inefficiently determines empty strings.str.trim().length()==0
orstr.trim().isEmpty()
(for the same reason) is quite inefficient as trim() causes a new String to be created. A Smarter code to check for an empty string would be:private boolean checkTrimEmpty(String str) { for(int i = 0; i < str.length(); i++) { if(!Character.isWhitespace(str.charAt(i))) { return false; } } return true; }
or you can refer to Apache'sStringUtils#isBlank
(in commons-lang), Spring'sStringUtils#hasText
(in the Spring framework) or Google'sCharMatcher#whitespace
(in Guava) for existing implementations (some might include the check for != null).- Author:
- acaplan
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Field Summary
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Fields inherited from class net.sourceforge.pmd.properties.AbstractPropertySource
propertyDescriptors, propertyValuesByDescriptor
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Fields inherited from interface net.sourceforge.pmd.Rule
VIOLATION_SUPPRESS_REGEX_DESCRIPTOR, VIOLATION_SUPPRESS_XPATH_DESCRIPTOR
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Constructor Summary
Constructors Constructor Description InefficientEmptyStringCheckRule()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Object
visit(ASTPrimaryExpression node, Object data)
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Methods inherited from class net.sourceforge.pmd.lang.java.rule.AbstractJavaRule
apply, getDeclaringType, importsPackage, isQualifiedName, isSuppressed, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visitAll
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Methods inherited from class net.sourceforge.pmd.lang.rule.AbstractRule
addExample, addRuleChainVisit, addRuleChainVisit, addViolation, addViolation, addViolation, addViolationWithMessage, addViolationWithMessage, addViolationWithMessage, asCtx, deepCopy, deepCopyValuesTo, end, equals, getDescription, getExamples, getExternalInfoUrl, getLanguage, getMaximumLanguageVersion, getMessage, getMinimumLanguageVersion, getName, getParserOptions, getPriority, getPropertySourceType, getRuleChainVisits, getRuleClass, getRuleSetName, getSince, hashCode, isDeprecated, isDfa, isMultifile, isRuleChain, isTypeResolution, setDeprecated, setDescription, setDfa, setExternalInfoUrl, setLanguage, setMaximumLanguageVersion, setMessage, setMinimumLanguageVersion, setMultifile, setName, setPriority, setRuleClass, setRuleSetName, setSince, setTypeResolution, setUsesDFA, setUsesMultifile, setUsesTypeResolution, start, usesDFA, usesMultifile, usesRuleChain, usesTypeResolution
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Methods inherited from class net.sourceforge.pmd.properties.AbstractPropertySource
copyPropertyDescriptors, copyPropertyValues, definePropertyDescriptor, dysfunctionReason, getOverriddenPropertiesByPropertyDescriptor, getOverriddenPropertyDescriptors, getPropertiesByPropertyDescriptor, getProperty, getPropertyDescriptor, getPropertyDescriptors, hasDescriptor, ignoredProperties, isPropertyOverridden, setProperty, setProperty, useDefaultValueFor, usesDefaultValues
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface net.sourceforge.pmd.properties.PropertySource
definePropertyDescriptor, dysfunctionReason, getOverriddenPropertiesByPropertyDescriptor, getOverriddenPropertyDescriptors, getPropertiesByPropertyDescriptor, getProperty, getPropertyDescriptor, getPropertyDescriptors, hasDescriptor, ignoredProperties, isPropertyOverridden, setProperty, setProperty, useDefaultValueFor, usesDefaultValues
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Method Detail
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visit
public Object visit(ASTPrimaryExpression node, Object data)
- Specified by:
visit
in interfaceJavaParserVisitor
- Overrides:
visit
in classAbstractJavaRule
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