JSON与JAVA的数据转换

http://developer.51cto.com/art/200906/129090.htm

 

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。

AD：

 

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]; }]