Gson和fastjson分别为谷歌和阿里巴巴对JSON数据进行处理封装的jar包
两者异同点：
相同点：都是根据JSON数据创建相应的类
不同点：
1.调用方式区别
谷歌：方法都是非静态的，需要先创建对象，再去调用
阿里：方法都是静态的，直接用类调用，不需要创建对象
2.方法区别：
谷歌：fromJson（参数1，参数2）
阿里：JSON.parseXX（参数1，参数2）
具体是parseObject（）还是parseArray（），根据需要定
要求：解析下面JSON数据
1.String string = “{name:’zhangsan’,age:18}”;
2.String string = “{persons:[{name:’zhangsan’,age:20},{name:’lisi’,age:21},{name:’wangwu’,age:22}]}”;
3.String string = “{no:1,name:’android’,employees:[{name:’zhangsan’,age:20},{name:’lisi’,age:21},{name:’wangwu’,age:22}]}”;
代码：
第一题：
package 谷歌和阿里解析JSON数据;
import com.google.gson.Gson;
public class Test {
public static void main(String[] args) {
//Gson解析JSON数据
//1.创建对象Person，有属性：name，age--创建结束
String string = "{name:'zhangsan',age:18}";
Gson gson=new Gson();
Person person=gson.fromJson(string, Person.class);
System.out.println(person.getName()+","+person.getAge());
}
}
class Person{
private String name;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + "]";
}
public Person(String name, int age) {
super();
this.name = name;
this.age = age;
}
public Person() {
super();
}
}
运行结果：
第2题：
package 谷歌和阿里解析JSON数据;
import java.util.ArrayList;
import com.google.gson.Gson;
public class Test2 {
public static void main(String[] args) {
//Gson解析时，遇到对象创建对象，这个对象里所有的内容键都作为对象的属性
//1.创建第一个对象，有属性：persons，且为集合
//2.persons集合里是对象，设对象为Person
//3.Person，它有两个属性：name，age
//4.相应的类创建完毕后，就可以解析了
String string = "{persons:[{name:'zhangsan',age:20},{name:'lisi',age:21},{name:'wangwu',age:22}]}";
Gson gson=new Gson();
Persons persons=gson.fromJson(string, Persons.class);
System.out.println(persons);
}
}
class Persons{
private ArrayList<Person1> persons;
public ArrayList<Person1> getPersons() {
return persons;
}
public void setPersons(ArrayList<Person1> persons) {
this.persons = persons;
}
@Override
public String toString() {
return "Persons [persons=" + persons + "]";
}
public Persons(ArrayList<Person1> persons) {
super();
this.persons = persons;
}
public Persons() {
super();
}
}
class Person1{
private String name;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + "]";
}
public Person1(String name, int age) {
super();
this.name = name;
this.age = age;
}
public Person1() {
super();
}
}
运行结果
第三题：
package 谷歌和阿里解析JSON数据;
import java.util.ArrayList;
import com.google.gson.Gson;
public class Test3 {
public static void main(String[] args) {
//1.第一个对象有属性：no，name，employees，且employees为集合
//2.employees数组中有对象，设该对象为Person
//3.Person有属性：name，age----创建结束
String string = "{no:1,name:'android',employees:[{name:'zhangsan',age:20},{name:'lisi',age:21},{name:'wangwu',age:22}]}";
Gson gson=new Gson();
Demo demo=gson.fromJson(string, Demo.class);
System.out.println(demo);
}
}
class Demo{
private int no;
private String name;
private ArrayList<Person2> employees;
public int getNo() {
return no;
}
public void setNo(int no) {
this.no = no;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public ArrayList<Person2> getEmployees() {
return employees;
}
public void setEmployees(ArrayList<Person2> employees) {
this.employees = employees;
}
@Override
public String toString() {
return "Demo [no=" + no + ", name=" + name + ", employees=" + employees + "]";
}
public Demo(int no, String name, ArrayList<Person2> employees) {
super();
this.no = no;
this.name = name;
this.employees = employees;
}
public Demo() {
super();
}
}
class Person2{
private String name;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + "]";
}
public Person2(String name, int age) {
super();
this.name = name;
this.age = age;
}
public Person2() {
super();
}
}
运行结果：