使用json-lib进行Java和JSON之间的转换【转载】
1. json-lib是一个java类库，提供将Java对象，包括beans, maps, collections, java arrays and XML等转换成JSON，或者反向转换的功能。
2. json-lib 主页 ： http://json-lib.sourceforge.net/
3.执行环境
需要以下类库支持
- jakarta commons-lang 2.5
- jakarta commons-beanutils 1.8.0
- jakarta commons-collections 3.2.1
- jakarta commons-logging 1.1.1
- ezmorph 1.0.6
4.功能示例
这里通过JUnit-Case例子给出代码示例
package com.mai.json; import static org.junit.Assert.assertEquals; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import net.sf.ezmorph.Morpher; import net.sf.ezmorph.MorpherRegistry; import net.sf.ezmorph.bean.BeanMorpher; import net.sf.json.JSONArray; import net.sf.json.JSONObject; import net.sf.json.util.JSONUtils; import org.apache.commons.beanutils.PropertyUtils; import org.junit.Test; public class JsonLibTest { /* * 普通类型、List、Collection等都是用JSONArray解析 * * Map、自定义类型是用JSONObject解析 * 可以将Map理解成一个对象，里面的key/value对可以理解成对象的属性/属性值 * 即{key1:value1,key2,value2......} * * 1.JSONObject是一个name:values集合，通过它的get(key)方法取得的是key后对应的value部分(字符串) * 通过它的getJSONObject(key)可以取到一个JSONObject，--> 转换成map, * 通过它的getJSONArray(key) 可以取到一个JSONArray ， * * */ //一般数组转换成JSON @Test public void testArrayToJSON(){ boolean[] boolArray = new boolean[]{true,false,true}; JSONArray jsonArray = JSONArray.fromObject( boolArray ); System.out.println( jsonArray ); // prints [true,false,true] } //Collection对象转换成JSON @Test public void testListToJSON(){ List list = new ArrayList(); list.add( "first" ); list.add( "second" ); JSONArray jsonArray = JSONArray.fromObject( list ); System.out.println( jsonArray ); // prints ["first","second"] } //字符串json转换成json， 根据情况是用JSONArray或JSONObject @Test public void testJsonStrToJSON(){ JSONArray jsonArray = JSONArray.fromObject( "['json','is','easy']" ); System.out.println( jsonArray ); // prints ["json","is","easy"] } //Map转换成json， 是用jsonObject @Test public void testMapToJSON(){ 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 jsonObject = JSONObject.fromObject( map ); System.out.println( jsonObject ); } //复合类型bean转成成json @Test public void testBeadToJSON(){ MyBean bean = new MyBean(); bean.setId("001"); bean.setName("银行卡"); bean.setDate(new Date()); List cardNum = new ArrayList(); cardNum.add("农行"); cardNum.add("工行"); cardNum.add("建行"); cardNum.add(new Person("test")); bean.setCardNum(cardNum); JSONObject jsonObject = JSONObject.fromObject(bean); System.out.println(jsonObject); } //普通类型的json转换成对象 @Test public void testJSONToObject() throws Exception{ String json = "{name=\"json\",bool:true,int:1,double:2.2,func:function(a){ return a; },array:[1,2]}"; JSONObject jsonObject = JSONObject.fromObject( json ); System.out.println(jsonObject); 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" ) ); System.out.println(PropertyUtils.getProperty(bean, "name")); System.out.println(PropertyUtils.getProperty(bean, "bool")); System.out.println(PropertyUtils.getProperty(bean, "int")); System.out.println(PropertyUtils.getProperty(bean, "double")); System.out.println(PropertyUtils.getProperty(bean, "func")); System.out.println(PropertyUtils.getProperty(bean, "array")); List arrayList = (List)JSONArray.toCollection(jsonObject.getJSONArray("array")); for(Object object : arrayList){ System.out.println(object); } } //将json解析成复合类型对象, 包含List @Test public void testJSONToBeanHavaList(){ String json = "{list:[{name:'test1'},{name:'test2'}],map:{test1:{name:'test1'},test2:{name:'test2'}}}"; // String json = "{list:[{name:'test1'},{name:'test2'}]}"; Map classMap = new HashMap(); classMap.put("list", Person.class); MyBeanWithPerson diyBean = (MyBeanWithPerson)JSONObject.toBean(JSONObject.fromObject(json),MyBeanWithPerson.class , classMap); System.out.println(diyBean); List list = diyBean.getList(); for(Object o : list){ if(o instanceof Person){ Person p = (Person)o; System.out.println(p.getName()); } } } //将json解析成复合类型对象, 包含Map @Test public void testJSONToBeanHavaMap(){ //把Map看成一个对象 String json = "{list:[{name:'test1'},{name:'test2'}],map:{testOne:{name:'test1'},testTwo:{name:'test2'}}}"; Map classMap = new HashMap(); classMap.put("list", Person.class); classMap.put("map", Map.class); //使用暗示，直接将json解析为指定自定义对象，其中List完全解析,Map没有完全解析 MyBeanWithPerson diyBean = (MyBeanWithPerson)JSONObject.toBean(JSONObject.fromObject(json),MyBeanWithPerson.class , classMap); System.out.println(diyBean); System.out.println("do the list release"); List<Person> list = diyBean.getList(); for(Person o : list){ Person p = (Person)o; System.out.println(p.getName()); } System.out.println("do the map release"); //先往注册器中注册变换器，需要用到ezmorph包中的类 MorpherRegistry morpherRegistry = JSONUtils.getMorpherRegistry(); Morpher dynaMorpher = new BeanMorpher( Person.class, morpherRegistry); morpherRegistry.registerMorpher( dynaMorpher ); Map map = diyBean.getMap(); /*这里的map没进行类型暗示，故按默认的，里面存的为net.sf.ezmorph.bean.MorphDynaBean类型的对象*/ System.out.println(map); /*输出: {testOne=net.sf.ezmorph.bean.MorphDynaBean@f73c1[ {name=test1} ], testTwo=net.sf.ezmorph.bean.MorphDynaBean@186c6b2[ {name=test2} ]} */ List<Person> output = new ArrayList(); for( Iterator i = map.values().iterator(); i.hasNext(); ){ //使用注册器对指定DynaBean进行对象变换 output.add( (Person)morpherRegistry.morph( Person.class, i.next() ) ); } for(Person p : output){ System.out.println(p.getName()); /*输出: test1 test2 */ } } }
