java 和 json 对象间转换
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
commons-lang 2.5
commons-beanutils 1.8.0
commons-collections 3.2.1
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
*/
}
}
}
5.下面提供上面例子所需的资源，包括jar包和代码
/files/mailingfeng/json-lib/json-lib用例所需jar包和java类.rar