这篇文章主要介绍了Java实现Json字符串与Object对象相互转换的方式,结合实例形式总结分析了java基于Json-Lib、Org.Json、Jackson、Gson、FastJson五种方式转换json类型相关操作技巧,需要的朋友可以参考下
本文实例总结了Java实现Json字符串与Object对象相互转换的方式。分享给大家供大家参考,具体如下:
Json-Lib、Org.Json、Jackson、Gson、FastJson五种方式转换json类型
只列举了最省事的方式。不涉及复制情况和速度。
测试用例,一个User类,属性name,age,location。重写toString()。
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public class User {
private String name; private Integer age; private String location; public User() {
} public User(String name) {
this .name = name; } public User(String name, Integer age) {
this .name = name; this .age = age; } public User(String name, Integer age, String location) {
this .name = name; this .age = age; this .location = location; } public String getName() {
return name; } public void setName(String name) {
this .name = name; } public Integer getAge() {
return age; } public void setAge(Integer age) {
this .age = age; } public String getLocation() {
return location; } public void setLocation(String location) {
this .location = location; } @Override public String toString() {
return "User{" + "name='" + name + '\ '' + ", age=" + age + ", location='" + location + '\ '' + '}' ; } } |
1、Json-Lib
maven依赖如下,需注意<classifier>jdk15</classifier>,jar包区分jdk1.3和jdk1.5版本
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< dependency > < groupId >net.sf.json-lib</ groupId > < artifactId >json-lib</ artifactId > < version >2.4</ version > < classifier >jdk15</ classifier > </ dependency > |
测试demo
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import net.sf.json.JSONObject; public class JsonLibDemo {
public static void main(String[] args) {
//创建测试object User user = new User( "李宁" , 24 , "北京" ); System.out.println(user); //转成json字符串 JSONObject jsonObject = JSONObject.fromObject(user); String json = jsonObject.toString(); System.out.println(json); //json字符串转成对象 JSONObject jsonObject1 = JSONObject.fromObject(json); User user1 = (User) JSONObject.toBean(jsonObject1,User. class ); System.out.println(user1); } } |
2、org.json
maven依赖如下
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< dependency > < groupId >org.json</ groupId > < artifactId >json</ artifactId > < version >20170516</ version > </ dependency > |
测试demo
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import org.json.JSONObject; public class OrgJsonDemo {
public static void main(String[] args) {
//创建测试object User user = new User( "李宁" , 24 , "北京" ); System.out.println(user); //转成json字符串 String json = new JSONObject(user).toString(); System.out.println(json); //json字符串转成对象 JSONObject jsonObject = new JSONObject(json); String name = jsonObject.getString( "name" ); Integer age = jsonObject.getInt( "age" ); String location = jsonObject.getString( "location" ); User user1 = new User(name,age,location); System.out.println(user1); } } |
3、Jackson
maven依赖
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< dependency > < groupId >com.fasterxml.jackson.core</ groupId > < artifactId >jackson-databind</ artifactId > < version >2.9.0</ version > </ dependency > |
测试demo
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import com.fasterxml.jackson.databind.ObjectMapper; public class JacksonDemo {
public static void main(String[] args) {
//创建测试object User user = new User( "李宁" , 24 , "北京" ); System.out.println(user); //转成json字符串 ObjectMapper mapper = new ObjectMapper(); try {
String json = mapper.writeValueAsString(user); System.out.println(json); //json字符串转成对象 User user1 = mapper.readValue(json,User. class ); System.out.println(user1); } catch (java.io.IOException e) {
e.printStackTrace(); } } } |
4、Gson
maven依赖
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< dependency > < groupId >com.google.code.gson</ groupId > < artifactId >gson</ artifactId > < version >2.8.1</ version > </ dependency > |
测试demo
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import com.google.gson.Gson; public class GsonDemo {
public static void main(String[] args) {
//创建测试object User user = new User( "李宁" , 24 , "北京" ); System.out.println(user); //转成json字符串 Gson gson = new Gson(); String json = gson.toJson(user); System.out.println(json); //json字符串转成对象 User user1 = gson.fromJson(json,User. class ); System.out.println(user1); } } |
5、FastJson
maven依赖
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< dependency > < groupId >com.alibaba</ groupId > < artifactId >fastjson</ artifactId > < version >1.2.37</ version > </ dependency > |
测试demo
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import com.alibaba.fastjson.JSON; public class FastJsonDemo {
public static void main(String[] args) {
//创建测试object User user = new User( "李宁" , 24 , "北京" ); System.out.println(user); //转成json字符串 String json = JSON.toJSON(user).toString(); System.out.println(json); //json字符串转成对象 User user1 = JSON.parseObject(json,User. class ); System.out.println(user1); } } |
json-lib时间有些久远,jar包只更新到2010年
org.json用起来有些繁琐
Jackson、Gson、FastJson只需一两句话就可以搞定