Flex 对Java端返回Collection的处理方法

将Flex与Spring集成后（BlazeDS 与Spring集成指南 ），第一个面临的问题就是：对于Java端返回的各种Java类型的对象，Flex中能否有相应的数据类型来映射。

处理，尤其是List、Set、Map及POJO对象值。

在 BlazeDS 与Spring集成指南 例子的基础上，调整相关的测试代码如下：

 1、Java端
 1.1、com.yeeach.HelloWorldService
 package com.yeeach; 

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set; 

 public class HelloWorldService {
     public String hello(String var1) {
         return "hello " + var1;
     }
     public String world(String var1) {
         return "world " + var1;
     }
     public Map<String,List<String>> getMap() {
         ArrayList<String> list1=new ArrayList<String>();
         list1.add("value11");
         list1.add("value12");
         list1.add("value13");
         ArrayList<String> list2=new ArrayList<String>();
         list2.add("value21");
         list2.add("value22");
         list2.add("value23");
         ArrayList<String> list3=new ArrayList<String>();
         list3.add("value31");
         list3.add("value32");
         list3.add("value33");
         HashMap<String,List<String>> map=new HashMap<String,List<String>>();
         map.put("key1", list1);
         map.put("key2", list2);
         map.put("key3", list3);
         return map;
     }
     public ArrayList<Person> getList() {
         ArrayList <Person> list=new ArrayList<Person>();
         Person p1=new Person();
         p1.setName("name1");
         p1.setPass("pass1");
         Person p2=new Person();
         p2.setName("name2");
         p2.setPass("pass2");
         Person p3=new Person();
         p3.setName("name3");
         p3.setPass("pass3");
         list.add(p1);
         list.add(p2);
         list.add(p3);
         return list;
     }
     public Set<Person> getSet() {
         HashSet<Person>  set=new HashSet<Person>();
         Person p1=new Person();
         p1.setName("name1");
         p1.setPass("pass1");
         Person p2=new Person();
         p2.setName("name2");
         p2.setPass("pass2");
         Person p3=new Person();
         p3.setName("name3");
         p3.setPass("pass3");
         set.add(p1);
         set.add(p2);
         set.add(p3);
         return set;
     }
 } 

 1.2、com.yeeach.Person
 package com.yeeach; 

 public class Person { 

         public String getName() {
             return name;
         }
         public void setName(String name) {
             this.name = name;
         }
         public String getPass() {
             return pass;
         }
         public void setPass(String pass) {
             this.pass = pass;
         }
         private String name;
         private String pass; 

 }

2、Flex 端

2.1、helloworld.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
                layout="vertical">
    <mx:RemoteObject destination="test1"
                     id="test1">
        <mx:method name="hello"
                   result="sayHelloResult(event)"/>
        <mx:method name="world"
                   result="sayWorldResult(event)"/>
        <mx:method name="getMap"
                   result="getMapResult(event)"/>
        <mx:method name="getList"
                   result="getListResult(event)"/>
        <mx:method name="getSet"
                   result="getSetResult(event)"/>
    </mx:RemoteObject>
    <mx:HBox>
        <mx:Label text="输入："/>
        <mx:TextInput id="inputStr"/>
        <mx:Button label="say hello"
                   click="sayHello(event);"/>
        <mx:Button label="say world"
                   click="sayWorld(event);"/>
        <mx:Button label="get map"
                   click="test1.getMap()"/>
        <mx:Button label="get list"
                   click="test1.getList()"/>
        <mx:Button label="get set"
                   click="test1.getSet()"/>
    </mx:HBox>
    <mx:HBox>
        <mx:Label text="结果："/>
        <mx:TextArea id="result"/>
    </mx:HBox> 

    <mx:Script> 

        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.rpc.events.FaultEvent;
            import mx.controls.Alert;
            import mx.rpc.events.ResultEvent;
            import com.yeeach.Person;
            [Bindable]
            public var person:Person;
            [Bindable] 

            public var map:ArrayCollection=null; 

            function sayHello(event:Event):void
            {
                var inputVar:String=inputStr.text;
                test1.hello(inputVar); 

            } 

            function sayWorld(event:Event):void
            {
                var inputVar:String=inputStr.text;
                test1.world(inputVar); 

            } 

            private function sayHelloResult(event:ResultEvent):void
            {
                result.text=event.result.toString();
                Alert.show(event.result.toString(), "返回结果");
            } 

            private function sayWorldResult(event:ResultEvent):void
            {
                result.text=event.result.toString();
                Alert.show(event.result.toString(), "返回结果");
            } 

            private function getMapResult(event:ResultEvent):void
            {
                for (var key:String in event.result)
                {
                    var list:ArrayCollection=event.result[key] as ArrayCollection;
                    for (var key1:Object in list)
                    {
                        Alert.show("map item key is: " + key + " value is: " + key1);
                    } 

                }
            } 

            private function getList():void
            {
                test1.getList();
            } 

            private function getListResult(event:ResultEvent):void
            {
                var ac:ArrayCollection=event.result as ArrayCollection;
                for (var i:int=0; i < ac.length; i++)
                {
                    var p1:Person=ac.getItemAt(i) as Person;
                    Alert.show("list item name is: " + p1.name+" \n another usage : "+ac.getItemAt(i).name);
                } 

            }
            private function getSet():void
            {
                test1.getSet();
            } 

            private function getSetResult(event:ResultEvent):void
            {
                var ac:ArrayCollection=event.result as ArrayCollection;
                for (var i:int=0; i < ac.length; i++)
                {
                    var p1:Person=ac.getItemAt(i) as Person;
                    Alert.show("set item name  is: " + p1.name);
                } 

            }
        ]]>
    </mx:Script>
</mx:Application>

2.2、com.yeeach.Person.as
package com.yeeach
{
    [Bindable]
    [RemoteClass(alias="com.yeeach.Person")]
    public class Person
    {
        public var name:String;
        public var pass:String;
    }
}

　　

1、JavaBean从Java端返回给Flex，可以通过Flex的Meta Tag [RemoteClass (alias=” “)]来标识服务器端对应的Java的类（一般为POJO对象）。

注意位置，是在class声明前。

2、Java Collection返回给Flex，都可以通过转化为mx.collections.ArrayCollection来进行处理。

3、Flex对于服务器端返回的java其他类型的处理，相对简单，可以参考

http://livedocs.adobe.com/flex/3/html/help.html?content=data_access_4.html