org.dizitart.no2.filters

Class Filters

java.lang.Object

org.dizitart.no2.filters.Filters

public final class Filters
extends java.lang.Object

A helper class to create all type of Filters.

Since:

1.0

Field Summary

Fields

Modifier and Type	Field and Description
static Filter	ALL A filter to select all elements.

Method Summary

Modifier and Type	Method and Description
static Filter	and(Filter... filters) Creates an and filter which performs a logical AND operation on two filters and selects the documents that satisfy both filters.
static Filter	elemMatch(java.lang.String field, Filter filter) Creates an element match filter that matches documents that contain an array value with at least one element that matches the specified filter.
static Filter	eq(java.lang.String field, java.lang.Object value) Creates an equality filter which matches documents where the value of a field equals the specified value.
static Filter	gt(java.lang.String field, java.lang.Object value) Creates a greater than filter which matches those documents where the value of the value is greater than (i.e.
static Filter	gte(java.lang.String field, java.lang.Object value) Creates a greater equal filter which matches those documents where the value of the value is greater than or equals to (i.e.
static Filter	in(java.lang.String field, java.lang.Object... values) Creates an in filter which matches the documents where the value of a field equals any value in the specified array.
static Filter	lt(java.lang.String field, java.lang.Object value) Creates a lesser than filter which matches those documents where the value of the value is less than (i.e.
static Filter	lte(java.lang.String field, java.lang.Object value) Creates a lesser equal filter which matches those documents where the value of the value is lesser than or equals to (i.e.
static Filter	not(Filter filter) Creates a not filter which performs a logical NOT operation on a filter and selects the documents that do not satisfy the filter.
static Filter	or(Filter... filters) Creates an or filter which performs a logical OR operation on two filters and selects the documents that satisfy at least one of the filter.
static Filter	regex(java.lang.String field, java.lang.String value) Creates a string filter which provides regular expression capabilities for pattern matching strings in documents.
static Filter	text(java.lang.String field, java.lang.String value) Creates a text filter which performs a text search on the content of the fields indexed with a full-text index.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ALL

public static final Filter ALL

A filter to select all elements.

Method Detail

eq

public static Filter eq(java.lang.String field,
                        java.lang.Object value)

Creates an equality filter which matches documents where the value of a field equals the specified value.

Example

// matches all documents where 'age' field has value as 30
collection.find(eq("age", 30));

Parameters:

field - the value

value - the value

Returns:

the equality filter.

and

public static Filter and(Filter... filters)

Creates an and filter which performs a logical AND operation on two filters and selects the documents that satisfy both filters.

Example

// matches all documents where 'age' field has value as 30 and
// 'name' field has value as John Doe
collection.find(and(eq("age", 30), eq("name", "John Doe")));

Parameters:

filters - operand filters

Returns:

the and filter

or

public static Filter or(Filter... filters)

Creates an or filter which performs a logical OR operation on two filters and selects the documents that satisfy at least one of the filter.

Example

// matches all documents where 'age' field has value as 30 or
// 'name' field has value as John Doe
collection.find(or(eq("age", 30), eq("name", "John Doe")));

Parameters:

filters - operand filters

Returns:

the or filter

not

public static Filter not(Filter filter)

Creates a not filter which performs a logical NOT operation on a filter and selects the documents that do not satisfy the filter. This also includes documents that do not contain the value.

Example

// matches all documents where 'age' field has value not equals to 30
collection.find(not(eq("age", 30)));

Parameters:

filter - the filter

Returns:

the not filter

gt

public static Filter gt(java.lang.String field,
                        java.lang.Object value)

Creates a greater than filter which matches those documents where the value of the value is greater than (i.e. >) the specified value.

Example

// matches all documents where 'age' field has value greater than 30
collection.find(gt("age", 30));

Parameters:

field - the value

value - the value

Returns:

the greater than filter

gte

public static Filter gte(java.lang.String field,
                         java.lang.Object value)

Creates a greater equal filter which matches those documents where the value of the value is greater than or equals to (i.e. >=) the specified value.

Example

// matches all documents where 'age' field has value greater than or equal to 30
collection.find(gte("age", 30));

Parameters:

field - the value

value - the value

Returns:

the greater or equal filter

lt

public static Filter lt(java.lang.String field,
                        java.lang.Object value)

Creates a lesser than filter which matches those documents where the value of the value is less than (i.e. <) the specified value.

Example

// matches all documents where 'age' field has value less than 30
collection.find(lt("age", 30));

Parameters:

field - the value

value - the value

Returns:

the lesser than filter

lte

public static Filter lte(java.lang.String field,
                         java.lang.Object value)

Creates a lesser equal filter which matches those documents where the value of the value is lesser than or equals to (i.e. ⇐) the specified value.

Example

// matches all documents where 'age' field has value lesser than or equal to 30
collection.find(lte("age", 30));

Parameters:

field - the value

value - the value

Returns:

the lesser equal filter

text

public static Filter text(java.lang.String field,
                          java.lang.String value)

Creates a text filter which performs a text search on the content of the fields indexed with a full-text index.

Example

// matches all documents where 'address' field has value 'roads'.
collection.find(text("address", "roads"));

Parameters:

field - the value

value - the text value

Returns:

the text filter

See Also:

TextIndexingService, TextTokenizer

regex

public static Filter regex(java.lang.String field,
                           java.lang.String value)

Creates a string filter which provides regular expression capabilities for pattern matching strings in documents.

Example

// matches all documents where 'name' value starts with 'jim' or 'joe'.
collection.find(regex("name", "^(jim|joe).*"));

Parameters:

field - the value

value - the regular expression

Returns:

the regex filter

in

public static Filter in(java.lang.String field,
                        java.lang.Object... values)

Creates an in filter which matches the documents where the value of a field equals any value in the specified array.

Example

// matches all documents where 'age' field has value in [20, 30, 40]
collection.find(in("age", 20, 30, 40));

Parameters:

field - the value

values - the range values

Returns:

the in filter

elemMatch

public static Filter elemMatch(java.lang.String field,
                               Filter filter)

Creates an element match filter that matches documents that contain an array value with at least one element that matches the specified filter.

Example

// matches all documents which has an array field - 'color' and the array
// contains a value - 'red'.
collection.find(elemMatch("color", eq("$", "red"));

Parameters:

field - the value

filter - the filter to satisfy

Returns:

the element match filter