JSON与JAVA的数据转换

本文介绍如何使用JSON-lib这个Java类包实现Java的数据转换。通过此类包可以把bean，map和XML转换成JSON并能够把JSON转回成bean和DynaBean。
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

boolean[] boolArray = new boolean[]{true,false,true};       
JSONArray jsonArray1 = JSONArray.fromObject( boolArray );      
System.out.println( jsonArray1 );      
// prints [true,false,true]     
   
List list = new ArrayList();      
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"]      

boolean[] boolArray = new boolean[]{true,false,true};    
JSONArray jsonArray1 = JSONArray.fromObject( boolArray );    
System.out.println( jsonArray1 );    
  // prints [true,false,true]   
   
  List list = new ArrayList();    
  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



Map map = new HashMap();      
map.put( "name", "json" );      
map.put( "bool", Boolean.TRUE );      
   
map.put( "int", new Integer(1) );      
map.put( "arr", new String[]{"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}   

Map map = new HashMap();    
map.put( "name", "json" );    
map.put( "bool", Boolean.TRUE );    
  
map.put( "int", new Integer(1) );    
map.put( "arr", new String[]{"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

       
   JSONObject jsonObject = JSONObject.fromObject( new JsonBean() );      
   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]; }}     


JSONObject jsonObject = JSONObject.fromObject( new JsonBean() );    
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

     
List list = new ArrayList();   
        JsonBean2 jb1 = new JsonBean2();   
        jb1.setCol(1);   
        jb1.setRow(1);   
        jb1.setValue("xx");   
           
        JsonBean2 jb2 = new JsonBean2();   
        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}]   

   
List list = new ArrayList(); 
        JsonBean2 jb1 = new JsonBean2(); 
        jb1.setCol(1); 
        jb1.setRow(1); 
        jb1.setValue("xx"); 
         
        JsonBean2 jb2 = new JsonBean2(); 
        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

    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" ) );     

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" ) );    

  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" ),new Integer( bean.getCol())  );      
      assertEquals( jsonObject.get( "row" ), new Integer( bean.getRow() ) );      
      assertEquals( jsonObject.get( "value" ), bean.getValue() );     

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" ),new Integer( bean.getCol())  );    
    assertEquals( jsonObject.get( "row" ), new Integer( 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]; }]