org.josql.functions

类 CollectionFunctions

java.lang.Object

org.josql.functions.AbstractFunctionHandler

org.josql.functions.CollectionFunctions

所有已实现的接口:

FunctionHandler

public class CollectionFunctions
extends AbstractFunctionHandler

Defines a set of functions that operate on "collections" of objects in some way.

字段概要

字段

限定符和类型	字段和说明
static String	HANDLER_ID The id that can be used to get the "CollectionFunctions" handler object from the Query object.

从类继承的字段 org.josql.functions.AbstractFunctionHandler

q

构造器概要

构造器

构造器和说明
CollectionFunctions()

方法概要

限定符和类型	方法和说明
List	collect(Expression exp)
List	collect(List allobjs, Expression exp)
List	collect(List objs, Expression exp, String saveValueName)
int	count(Expression exp)
int	count(List allobjs, Expression exp)
int	count(List objs, Expression exp, Object value)
List	find(List objs, Expression exp)
List	foreach(Expression exp)
List	foreach(Expression listFunction, Expression exp)
List	foreach(List allobjs, Expression exp)
List	foreach(List objs, String exp)
Object	get(List l, Number n)
Object	get(Map m, Expression exp) Get a value from the specified Map.
Map	grp(List objs, Expression exp) Group objects from the List based upon the expression passed in.
Map	map(List objs, Expression exp) Create a map of the objects passed in, the key will be the object in the list and the value will be the result of calling the expression on the object.
Map	map(List objs, Expression keyExp, Expression valExp)
List	sort(List objs) Sort a list according to it's "natural" ordering (see Collections.sort(List)).
List	sort(Map m) Sort a Map by the keys in ascending order (for more optionality in the sort and ordering see: sort(Map,String,String)).
List	sort(Map m, String type) Sort a Map by it's keys or values in ascending order (for more optionality in the sort and ordering see: sort(Map,String,String)).
List	sort(Map m, String type, String dir)
List	toList(Expression exp)
List	toList(List allobjs, Expression exp)
List	toList(List allobjs, Expression exp, String saveValueName)
List	unique(Expression exp)
List	unique(List objs)
List	unique(List objs, Expression exp)

从类继承的方法 org.josql.functions.AbstractFunctionHandler

setQuery

从类继承的方法 java.lang.Object

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

字段详细资料

HANDLER_ID

public static final String HANDLER_ID

The id that can be used to get the "CollectionFunctions" handler object from the Query object.

另请参阅:

常量字段值

构造器详细资料

CollectionFunctions

public CollectionFunctions()

方法详细资料

sort

public List sort(List objs)

Sort a list according to it's "natural" ordering (see Collections.sort(List)).

参数:

objs - The list of objects to sort.

返回:

The sorted list, according to their natural ordering.

sort

public List sort(Map m)

Sort a Map by the keys in ascending order (for more optionality in the sort and ordering see: sort(Map,String,String)).

参数:

m - The map to sort.

返回:

A List sorted according to the key in ascending order.

sort

public List sort(Map m,
                 String type)

Sort a Map by it's keys or values in ascending order (for more optionality in the sort and ordering see: sort(Map,String,String)).

参数:

m - The map to sort.

type - Should be either: "key" or "value" to indicate which item to sort on. Use null for key.

返回:

A List sorted according to the key in ascending order.

sort

public List sort(Map m,
                 String type,
                 String dir)

get

public Object get(Map m,
                  Expression exp)
           throws QueryExecutionException

Get a value from the specified Map.

参数:

m - The map of objects.

exp - The expression is evaluated (in the context of the current object) and the value returned used as the key to the Map, the value it maps to (which may be null) is returned.

返回:

The value that the exp value maps to, may be null.

抛出:

QueryExecutionException

get

public Object get(List l,
                  Number n)

count

public int count(List objs,
                 Expression exp,
                 Object value)
          throws QueryExecutionException

抛出:

QueryExecutionException

count

public int count(Expression exp)
          throws QueryExecutionException

抛出:

QueryExecutionException

count

public int count(List allobjs,
                 Expression exp)
          throws QueryExecutionException

抛出:

QueryExecutionException

toList

public List toList(List allobjs,
                   Expression exp,
                   String saveValueName)
            throws QueryExecutionException

抛出:

QueryExecutionException

unique

public List unique(List objs)

unique

public List unique(Expression exp)
            throws QueryExecutionException

抛出:

QueryExecutionException

unique

public List unique(List objs,
                   Expression exp)
            throws QueryExecutionException

抛出:

QueryExecutionException

collect

public List collect(List objs,
                    Expression exp,
                    String saveValueName)
             throws QueryExecutionException

抛出:

QueryExecutionException

collect

public List collect(Expression exp)
             throws QueryExecutionException

抛出:

QueryExecutionException

collect

public List collect(List allobjs,
                    Expression exp)
             throws QueryExecutionException

抛出:

QueryExecutionException

toList

public List toList(Expression exp)
            throws QueryExecutionException

抛出:

QueryExecutionException

toList

public List toList(List allobjs,
                   Expression exp)
            throws QueryExecutionException

抛出:

QueryExecutionException

foreach

public List foreach(Expression exp)
             throws QueryExecutionException

抛出:

QueryExecutionException

foreach

public List foreach(List allobjs,
                    Expression exp)
             throws QueryExecutionException

抛出:

QueryExecutionException

foreach

public List foreach(List objs,
                    String exp)
             throws QueryExecutionException

抛出:

QueryExecutionException

foreach

public List foreach(Expression listFunction,
                    Expression exp)
             throws QueryExecutionException

抛出:

QueryExecutionException

find

public List find(List objs,
                 Expression exp)
          throws QueryExecutionException

抛出:

QueryExecutionException

grp

public Map grp(List objs,
               Expression exp)
        throws QueryExecutionException

Group objects from the List based upon the expression passed in. The expression is evaulated for each object, by calling: Expression.getValue(Object,Query) and the return value used as the key to the Map. All objects with that value are added to a List held against the key. To maintain the ordering of the keys (if desirable) a LinkedHashMap is used as the return Map. Note: in accordance with the general operating methodology for the Query object, the ":_allobjs" special bind variable will be set to the the List passed in and the "_currobj" will be set to the relevant object in the List.

参数:

objs - The List of objects to search.

exp - The expression to evaulate against each object in the List.

返回:

The LinkedHashMap of matching objects, grouped according to the return value of executing the expression against each object in the input List.

抛出:

QueryExecutionException - If the expression cannot be evaulated against each object.

map

public Map map(List objs,
               Expression exp)
        throws QueryExecutionException

Create a map of the objects passed in, the key will be the object in the list and the value will be the result of calling the expression on the object. The expression is evaulated for each object, by calling: Expression.getValue(Object,Query) and the return value used as the value to the Map. To maintain the ordering of the keys (if desirable) a LinkedHashMap is used as the return Map. Note: in accordance with the general operating methodology for the Query object, the ":_allobjs" special bind variable will be set to the the List passed in and the "_currobj" will be set to the relevant object in the List.

参数:

objs - The List of objects to map.

exp - The expression to evaulate against each object in the List.

返回:

The LinkedHashMap of mapped objects.

抛出:

QueryExecutionException - If the expression cannot be evaulated against each object.

map

public Map map(List objs,
               Expression keyExp,
               Expression valExp)
        throws QueryExecutionException

抛出:

QueryExecutionException