1.下载Jar包
http://repo1.maven.org/maven2/com/alibaba/fastjson/
2.将jar包导入工程
3.示例
package nc.testFastJson;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;
public class TestFastJson {
public static void main(String[] args) {
// java对象 转 json
People p1 = new People("people_1","Male",1);
String p1_Json = JSON.toJSONString(p1);
System.out.println(p1_Json.toString());
// json 转 java对象
String p2_Json = "{'name':'people_2','sex':'Male','age':2}";
People p2 = JSON.parseObject(p2_Json, People.class);
System.out.println(p2.toString());
// java对象LinkedList集合 转 json
LinkedList<People> p_list = new LinkedList<>();
People p3 = new People("people_3","Male",3);
People p4 = new People("people_4","Male",4);
People p5 = new People("people_5","Male",5);
p_list.add(p3);
p_list.add(p4);
p_list.add(p5);
String p_list_Json = JSON.toJSONString(p_list);
System.out.println(p_list_Json);
// json 转 java对象List集合
List<People> p_list_2 = JSON.parseArray(p_list_Json, People.class);
for (People people : p_list_2) {
System.out.println(people.toString());
}
// java对象ArrayList 转 json
ArrayList<People> arrayList = new ArrayList<>();
arrayList.add(p3);
arrayList.add(p4);
arrayList.add(p5);
String arrays_json = JSON.toJSONString(arrayList);
System.out.println(arrays_json);
// json 转 java对象List集合
List<People> arrayList2 = JSON.parseArray(arrays_json, People.class);
for (People people : arrayList2) {
System.out.println(people.toString());
}
// map 转 json
HashMap<String ,People> map = new HashMap<>();
map.put("p3", p3);
map.put("p4", p4);
map.put("p5", p5);
String map_json = JSON.toJSONString(map);
System.out.println(map_json);
// json 转 map
Map<String, String> map2 = JSONObject.parseObject(map_json.toString(), new TypeReference<Map<String, String>>(){});
Set<Entry<String, String>> entrySet = map2.entrySet();
for (Entry<String, String> entry : entrySet) {
String key = entry.getKey();
String value = entry.getValue();
People p = JSON.parseObject(value, People.class);
System.out.println(key+":"+p.toString());
}
}
}
package nc.testFastJson;
public class People {
private String name ;
private String sex ;
private int age ;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "People [name=" + name + ", sex=" + sex + ", age=" + age + "]";
}
public People() {
super();
}
public People(String name, String sex, int age) {
super();
this.name = name;
this.sex = sex;
this.age = age;
}
}

来源:https://www.cnblogs.com/NEWHOM/p/7299634.html