Java Json 序列化与反序列化
JSON</strong>(JavaScript Object Notation) 是一种轻量级的数据交换格式。 易于人阅读和编写。同时也易于机器解析和生成。 它基于JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999的一个子集。 JSON采用完全独立于语言的文本格式，这些特性使JSON成为理想的数据交换语言。</span> 下面介绍两款自己在开发中常用的处理Json的Java开源类库：Gson和Fastjson 1、Gson Gson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of. Gson官网：http://code.google.com/p/google-gson/ Gson User Guide：https://sites.google.com/site/gson/gson-user-guide 2、Fastjson Fastjson是一个json处理工具包，由阿里巴巴公司开发，包括“序列化”和“反序列化”两部分，它具备如下特征：
package com.example.testjson.entity; import java.util.Date; import java.util.List; import java.util.Map; public class Person { private String name; private FullName fullName; private int age; private Date birthday; private List<String> hobbies; private Map<String, String> clothes; private List<Person> friends; public String getName() { return name; } public void setName(String name) { this.name = name; } public FullName getFullName() { return fullName; } public void setFullName(FullName fullName) { this.fullName = fullName; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public List<String> getHobbies() { return hobbies; } public void setHobbies(List<String> hobbies) { this.hobbies = hobbies; } public Map<String, String> getClothes() { return clothes; } public void setClothes(Map<String, String> clothes) { this.clothes = clothes; } public List<Person> getFriends() { return friends; } public void setFriends(List<Person> friends) { this.friends = friends; } @Override public String toString() { String str= "Person [name=" + name + ", fullName=" + fullName + ", age=" + age + ", birthday=" + birthday + ", hobbies=" + hobbies + ", clothes=" + clothes + "]\n"; if(friends!=null){ str+="Friends:\n"; for (Person f : friends) { str+="\t"+f; } } return str; } } class FullName { private String firstName; private String middleName; private String lastName; public FullName(){ } public FullName(String firstName, String middleName, String lastName) { super(); this.firstName = firstName; this.middleName = middleName; this.lastName = lastName; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getMiddleName() { return middleName; } public void setMiddleName(String middleName) { this.middleName = middleName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } @Override public String toString() { return "[firstName=" + firstName + ", middleName=" + middleName + ", lastName=" + lastName + "]"; } }
</div> package com.example.testjson.entity; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class PersonFactory { private static Person createABSPerson(String name,List<Person> friends) { Person newPerson = new Person(); newPerson.setName(name); newPerson.setFullName(new FullName(name+"_first", name+"_middle", name+"_last")); newPerson.setAge(24); List<String> hobbies=new ArrayList<String>(); hobbies.add("篮球"); hobbies.add("游泳"); hobbies.add("coding"); newPerson.setHobbies(hobbies); Map<String,String> clothes=new HashMap<String, String>(); clothes.put("coat", "Nike"); clothes.put("trousers", "adidas"); clothes.put("shoes", "安踏"); newPerson.setClothes(clothes); newPerson.setFriends(friends); return newPerson; } public static Person create(String name){ List<Person> friends=new ArrayList<Person>(); friends.add(createABSPerson("小明",null)); friends.add(createABSPerson("Tony",null)); friends.add(createABSPerson("陈小二",null)); return createABSPerson(name,friends); } }
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package com.example.testjson.gson; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonElement; import com.google.gson.JsonParser; public class GsonUtil { private static Gson gson = new GsonBuilder().create(); public static String bean2Json(Object obj){ return gson.toJson(obj); } public static <T> T json2Bean(String jsonStr,Class<T> objClass){ return gson.fromJson(jsonStr, objClass); } public static String jsonFormatter(String uglyJsonStr){ Gson gson = new GsonBuilder().setPrettyPrinting().create(); JsonParser jp = new JsonParser(); JsonElement je = jp.parse(uglyJsonStr); String prettyJsonString = gson.toJson(je); return prettyJsonString; } }
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package com.example.testjson.fastjson; import com.alibaba.fastjson.JSON; public class FastJsonUtil { public static String bean2Json(Object obj){ return JSON.toJSONString(obj); } public static <T> T json2Bean(String jsonStr,Class<T> objClass){ return JSON.parseObject(jsonStr, objClass); } }
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package com.example.testjson; import com.example.testjson.entity.Person; import com.example.testjson.entity.PersonFactory; import com.example.testjson.gson.GsonUtil; public class GsonTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Person p = PersonFactory.create("Kobe"); String json = GsonUtil.bean2Json(p); String prettyJsonString = GsonUtil.jsonFormatter(json); System.out.println("FastJson Serializing="+json); System.out.println("FastJson Serializing PrettyPrinting="+prettyJsonString); Person newPerson = GsonUtil.json2Bean(json, Person.class); System.out.println("FastJson Deserializing="+newPerson); } }
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package com.example.testjson; import com.example.testjson.entity.Person; import com.example.testjson.entity.PersonFactory; import com.example.testjson.fastjson.FastJsonUtil; public class FastJsonTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Person p = PersonFactory.create("Kobe"); String json = FastJsonUtil.bean2Json(p); System.out.println("FastJson Serializing="+json); Person newPerson = FastJsonUtil.json2Bean(json, Person.class); System.out.println("FastJson Deserializing="+newPerson); } }