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 + '\'' +
'}';
}
}
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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>
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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);
}
}
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2、org.json
maven依赖如下
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<dependency>
<groupid>org.json</groupid>
<artifactid>json</artifactid>
<version>20170516</version>
</dependency>
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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);
}
}
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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>
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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();
}
}
}
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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>
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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);
}
}
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5、fastjson
maven依赖
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<dependency>
<groupid>com.alibaba</groupid>
<artifactid>fastjson</artifactid>
<version>1.2.37</version>
</dependency>
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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);
}
}
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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
ps：关于json操作，这里再为大家推荐几款比较实用的json在线工具供大家参考使用：
在线json代码检验、检验、美化、格式化工具：https://tool.zzvips.com/t/jsonjiexi/
json在线格式化工具：https://tool.zzvips.com/t/jsonformat/
在线excel/json互相转换工具：https://tool.zzvips.com/t/excel2json/
json/excel互相转换工具：https://tool.zzvips.com/t/json2excel/
在线json压缩/转义工具：https://tool.zzvips.com/t/jsonzip/
希望本文所述对大家java程序设计有所帮助。
原文链接：https://blog.csdn.net/n447194252/article/details/77747465