java对象怎么转json数组

JSON-lib这个Java类包用于把bean,map和XML转换成JSON并能够把JSON转回成bean和DynaBean。

下载地址:http://json-lib.sourceforge.net/
还要需要的第3方包:
org.apache.commons(3.2以上版本)
org.apache.oro
net.sf.ezmorph(ezmorph-1.0.4.jar)
nu.xom

1、List
Java代码
boolean[] boolArray =newboolean[]{true,false,true};     
            JSONArray jsonArray1 = JSONArray.fromObject( boolArray );     
            System.out.println( jsonArray1 );     
           // prints [true,false,true]   
             
            List list =newArrayList();     
            list.add("first");     
            list.add("second");     
            JSONArray jsonArray2 = JSONArray.fromObject( list );     
            System.out.println( jsonArray2 );     
           // prints ["first","second"]   
 
            JSONArray jsonArray3 = JSONArray.fromObject("['json','is','easy']");     
            System.out.println( jsonArray3 );     
           // prints ["json","is","easy"]    

2、Map
Java代码
Map map =newHashMap();     
          map.put("name","json");     
          map.put("bool", Boolean.TRUE );     
           
          map.put("int",newInteger(1) );     
          map.put("arr",newString[]{"a","b"} );     
          map.put("func","function(i){ return this.arr[i]; }");     
          JSONObject json = JSONObject.fromObject( map );     
          System.out.println( json );     
         //{"func":function(i){ return this.arr[i]; },"arr":["a","b"],"int":1,"name":"json","bool":true} 

3、BEAN
Java代码
/**
      * Bean.java
         private String name = "json";  
         private int pojoId = 1;  
         private char[] ptions = new char[]{'a','f'};  
         private String func1 = "function(i){ return this.options[i]; }";  
         private JSONFunction func2 = new JSONFunction(new String[]{"i"},"return this.options[i];");
     */ 
JSONObject jsonObject = JSONObject.fromObject(newJsonBean() );     
System.out.println( jsonObject );     
//{"func1":function(i){ return this.options[i]; },"pojoId":1,"name":"json","options":["a","f"],"func2":function(i){ return this.options[i]; }}   

4、BEANS
Java代码
/**
       * private int row ;
           private int col ;
           private String value ;
       *
       */ 
List list =newArrayList();  
          JsonBean2 jb1 =newJsonBean2();  
          jb1.setCol(1);  
          jb1.setRow(1);  
          jb1.setValue("xx");  
           
          JsonBean2 jb2 =newJsonBean2();  
          jb2.setCol(2);  
          jb2.setRow(2);  
          jb2.setValue("");  
           
           
          list.add(jb1);  
          list.add(jb2);  
           
          JSONArray ja = JSONArray.fromObject(list);  
          System.out.println( ja.toString() );  
         //[{"value":"xx","row":1,"col":1},{"value":"","row":2,"col":2}] 

5、String to bean
Java代码
String json ="{name=\"json\",bool:true,int:1,double:2.2,func:function(a){ return a; },array:[1,2]}";     
JSONObject jsonObject = JSONObject.fromString(json);     
Object bean = JSONObject.toBean( jsonObject );     
assertEquals( jsonObject.get("name"), PropertyUtils.getProperty( bean,"name") );     
   assertEquals( jsonObject.get("bool"), PropertyUtils.getProperty( bean,"bool") );     
   assertEquals( jsonObject.get("int"), PropertyUtils.getProperty( bean,"int") );     
    assertEquals( jsonObject.get("double"), PropertyUtils.getProperty( bean,"double") );     
    assertEquals( jsonObject.get("func"), PropertyUtils.getProperty( bean,"func") );     
   List expected = JSONArray.toList( jsonObject.getJSONArray("array") );     
   assertEquals( expected, (List) PropertyUtils.getProperty( bean,"array") );   


Java代码
String json ="{\"value\":\"xx\",\"row\":1,\"col\":1}";     
JSONObject jsonObject = JSONObject.fromString(json);  
   JsonBean2 bean = (JsonBean2) JSONObject.toBean( jsonObject, JsonBean2.class);     
    assertEquals( jsonObject.get("col"),newInteger( bean.getCol())   );     
      assertEquals( jsonObject.get("row"),newInteger( bean.getRow() ) );     
      assertEquals( jsonObject.get("value"), bean.getValue() );   


6 json to xml
1)
JSONObject json = new JSONObject( true );
String xml = XMLSerializer.write( json );

<o class="object" null="true">

2)
JSONObject json = JSONObject.fromObject("{\"name\":\"json\",\"bool\":true,\"int\":1}");
String xml = XMLSerializer.write( json );
<o class="object">
<name type="string">json</name>
<bool type="boolean">true</bool>
<int type="number">1</int>
</o>
<o class="object">
<name type="string">json</name>
<bool type="boolean">true</bool>
<int type="number">1</int>
</o>
3)
JSONArray json = JSONArray.fromObject("[1,2,3]");
String xml = XMLSerializer.write( json );
<a class="array">
<e type="number">1</e>
<e type="number">2</e>
<e type="number">3</e>
</a>

7 、xml to json
<a class="array">
<e type="function" params="i,j">
return matrix[i][j];
</e>
</a>
<a class="array">
<e type="function" params="i,j">
return matrix[i][j];
</e>
</a>

JSONArray json = (JSONArray) XMLSerializer.read( xml );
System.out.println( json );
// prints [function(i,j){ return matrix[i][j]; }]