JSON解析工具-json-lib使用教程
jopen
10年前
一、简介
json-lib是一个Java类库，提供将Java对象，包括beans,maps,collections,java arrays和xml等转换成JSON,或者反向转换的功能。
二、准备
在使用json-lib之前，我们应该到官方网址下载如下包：
-
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
并将这些jar包引入到Eclipse项目当中，即可调用。
三、讲解
在进行下面的代码演示之前，我们先将几个基本的类介绍一下：
MyBean类：
public class MyBean { private String id = null; private String name = null; private Date date = null; private List cardNum = null; private String[] cardType = {"身份证", "银行卡" , "公车卡"}; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Date getDate() { return date; } public void setDate(Date date) { this.date = date; } public List getCardNum() { return cardNum; } public void setCardNum(List cardNum) { this.cardNum = cardNum; } public String[] getCardType() { return cardType; } public void setCardType(String[] cardType) { this.cardType = cardType; } } Person类：
public class Person { private String name = null; public Person(){ } public Person(String name){ this.name = name; } public String getName() { return name; } public void setName(String name) { this.name = name; } } MyBeanWithPerson类： public class MyBeanWithPerson { private List<Person> list = null; private Map<String,Person> map = null; public List getList() { return list; } public void setList(List list) { this.list = list; } public Map getMap() { return map; } public void setMap(Map map) { this.map = map; } } 1.将json字符串转换成JSON，根据情况用JSONArray或JSONObject
public static void testJsonStrToJSON() { JSONArray jsonArray = JSONArray.fromObject("[\"json\",\"is\",\"easy\"]"); System.out.println(jsonArray); } 2.将Java Bean转换成JSON对象
public static 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); } 3.将一般的数组转换成JSON
public static void testArrayToJSON() { boolean[] boolArray = new boolean[] { true, false, true }; JSONArray jsonArray = JSONArray.fromObject(boolArray); System.out.println(jsonArray); } 4.将Collection对象转换成JSON
public static void testListToJSON() { List list = new ArrayList(); list.add("first"); list.add("second"); JSONArray jsonArray = JSONArray.fromObject(list); System.out.println(jsonArray); }
5.将Map转换成JSON
public static 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); } 6.将普通类型的JSON字符串转换成JSON
public static void testJSONToObject() throws Exception { // 将JSon字符串转换成JsonObject对象 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); // 将JsonObject对象转换成JavaBean对象 Object bean = JSONObject.toBean(jsonObject); 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); } }
7.将复合类型的JSON字符串转换成复合对象，包含List
public static void testJSONToBeanHavaList() { 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()); } } } 8.将复合类型的JSON字符串转换成复合对象，包含Map
public static void testJSONToBeanHavaMap() { // 把Map看成一个对象 String json = "{list:[{name:\"test1\"},{name:\"test2\"}],map:{test1:{name:\"test1\"},test2:{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); ?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()); } }