JSON与JAVA数据的转换

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"]   

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}

3、BEAN

/**
     * Bean.java 
        private String name = "json";   
        private int pojoId = 1;   
        private char[] options = 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( 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

/**
      * private int row ;
          private int col ;
          private String value ;
      *
      */
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 = "{\"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]; }] 

评论

9 楼 rubylover 2009-06-10  

郁闷，我用BufferedReader的方式从一个xml文件里把内容读出来，形成一个xml格式的字符串xmlTxt。使用

JSONArray json = (JSONArray) XMLSerializer.read(xmlTxt);

咋就不能转成json对象呢。博主解答一下啊。

8 楼 minfirefox 2008-09-26  

您好！
请问我想只生成部分字段怎么办？

7 楼 falchion 2008-06-26  

引用

这个date类型显然不能填充到文本框中（文本框的格式为1988-04-28），那应该怎么转？

这个问题可以参考一下
如何转换日期格式的字段

6 楼 falchion 2008-06-24  

先生成树对象，然后转换成json数据。

5 楼 jlaccp 2008-06-23  

  你好 我想让数据库的字段形成json格式，你这有代码吗？
{
id:4,
text:'长途',
children:[
{
id:'4-1',
text:'G',
leaf:true
}
]
},
{
id:5,
text:'高速',
children:[
{
id:'5-1',
text:'H',
leaf:true
}
]
}
]
我想让数据库的值转换成json的形式后，可以形成前台的数据树。（树形结构）

4 楼 andrew.yulong 2008-06-17  

public class Demo {
	private String id;
	
	private Integer money;
	
	private Date bth;
	
	public Date getBth() {
		return bth;
	}

	public void setBth(Date bth) {
		this.bth = bth;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public Integer getMoney() {
		return money;
	}

	public void setMoney(Integer money) {
		this.money = money;
	}

	public static void main(String args[]){
		Demo demo = new Demo();
		demo.setId("1");
		demo.setMoney(Integer.valueOf(100));
		demo.setBth(new Date());
		JSONArray array = JSONArray.fromObject(demo);
		System.out.println(array.toString());
	}

}

一个bean里面又个date类型，转为json的话为

[{"money":100,"bth":{"month":5,"day":2,"year":108,"time":1213748332812,"seconds":52,"timezoneOffset":420,"date":17,"hours":17,"minutes":18},"id":"1"}]

这个date类型显然不能填充到文本框中（文本框的格式为1988-04-28），那应该怎么转？

3 楼 andrew.yulong 2008-06-17  

好像是的，我在测测是不是其他的问题
  谢了！

2 楼 falchion 2008-06-13  

andrew-yulong:你好！

引用

andrew.yulong 昨天 删除
你好，我想问下
如果我一个bean里面有个set集合，那该怎么办？JSONObject array = JSONObject.fromObject(bean);这个会报错

兄弟，没问题哪！

看看下面例子：

Bean.java

public class Bean {
	private String var1;
	private Set set1;
	
	public String getVar1() {
		return var1;
	}
	public void setVar1(String var1) {
		this.var1 = var1;
	}
	public Set getSet1() {
		return set1;
	}
	public void setSet1(Set set1) {
		this.set1 = set1;
	}
	
	
}

TestJSON.java

public class TestJSON {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Bean bean = new Bean();
		bean.setVar1("var1");
		Set set1 =  new HashSet();

		set1.add("test1");
		set1.add("test2");
		set1.add("test3");
		set1.add("test4");
		set1.add("test5");
		
		
		bean.setSet1(set1);
		JSONObject array = JSONObject.fromObject(bean);
		
		System.out.println(array);
		
	}

}

输出结果为

{"var1":"var1","set1":["test2","test3","test5","test4","test1"]}

1 楼 andrew.yulong 2008-06-11  

你好，我想问下
如果我一个bean里面有个set集合，那该怎么办？JSONObject array = JSONObject.fromObject(bean);这个会报错