org.josql.utils

类 JoSQLComparator

java.lang.Object

org.josql.utils.JoSQLComparator

所有已实现的接口:

Comparator

public class JoSQLComparator
extends Object
implements Comparator

构造器概要

构造器

构造器和说明
JoSQLComparator(Query q) Init this file filter with the query already built and parsed.
JoSQLComparator(String q) Init this filter with the query.

方法概要

限定符和类型	方法和说明
void	clearCache() Clear the cache, it is VITAL that you call this method before you use the comparator (if it has been used before) otherwise data objects will be "left around" and preventing the GC from cleaning them up.
int	compare(Object o1, Object o2) Compares the objects as according to the ORDER BY clause.
void	doExecuteOn(List l) Execute the EXECUTE ON ALL expressions.
Exception	getException() The Comparator.compare(Object,Object) method does not allow for any exceptions to be thrown however since the execution of the ORDER BY clause on the objects can cause the throwing of a QueryParseException it should be captured.
Query	getQuery() Get the Query we are using to process objects.
boolean	isCaching() Return whether this comparator uses caching to improve performance.
void	setCaching(boolean b) Set whether the comparator should use caching to improve performance.
void	setQuery(Query q) Set a new Query object for use in this filter.
void	setQuery(String q) Set a new Query (string form) for use in this filter.

从类继承的方法 java.lang.Object

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

从接口继承的方法 java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

构造器详细资料

JoSQLComparator

public JoSQLComparator(String q)
                throws QueryParseException

Init this filter with the query.

参数:

q - The query.

抛出:

QueryParseException - If there is an issue with the parsing of the query.

JoSQLComparator

public JoSQLComparator(Query q)
                throws IllegalStateException,
                       QueryParseException

Init this file filter with the query already built and parsed.

参数:

q - The query.

抛出:

IllegalStateException - If the Query object has not been parsed.

QueryParseException - If the FROM class is not as expected.

方法详细资料

doExecuteOn

public void doExecuteOn(List l)
                 throws QueryExecutionException

Execute the EXECUTE ON ALL expressions.

参数:

l - The list to execute the expressions on.

抛出:

QueryExecutionException

clearCache

public void clearCache()

Clear the cache, it is VITAL that you call this method before you use the comparator (if it has been used before) otherwise data objects will be "left around" and preventing the GC from cleaning them up.

isCaching

public boolean isCaching()
                  throws IllegalStateException

Return whether this comparator uses caching to improve performance.

返回:

true if caching is on.

抛出:

IllegalStateException - If the query has not yet been parsed or set.

setCaching

public void setCaching(boolean b)
                throws IllegalStateException

Set whether the comparator should use caching to improve performance.

参数:

b - Set to true to turn caching on.

抛出:

IllegalStateException - If the query has not yet been parsed or set.

compare

public int compare(Object o1,
                   Object o2)

Compares the objects as according to the ORDER BY clause.

指定者:

compare 在接口中 Comparator

参数:

o1 - The first object.

o2 - The second object.

getException

public Exception getException()

The Comparator.compare(Object,Object) method does not allow for any exceptions to be thrown however since the execution of the ORDER BY clause on the objects can cause the throwing of a QueryParseException it should be captured. If the exception is thrown then this method will return it.

返回:

The exception thrown by the execution of the ORDER BY clause in compare(Object,Object) or by sub-class/interface specific methods, this may be null if no exception was thrown.

setQuery

public void setQuery(String q)
              throws QueryParseException

Set a new Query (string form) for use in this filter.

参数:

q - The Query to use.

抛出:

QueryParseException - If there is an issue with the parsing of the query, or if the FROM class is not as expected.

setQuery

public void setQuery(Query q)
              throws IllegalStateException,
                     QueryParseException

Set a new Query object for use in this filter.

参数:

q - The Query to use.

抛出:

IllegalStateException - If the Query object has not been parsed.

QueryParseException - If the FROM class is not as expected.

getQuery

public Query getQuery()

Get the Query we are using to process objects.

返回:

The Query.