maven工程的依赖
<dependency>
<groupId>com.alibabagroupId>
<artifactId>fastjsonartifactId>
<version>1.2.45version>
dependency>
fastjsonJar包
创建两个实体类 一个是部门类,一个是部门员工类
部门员工类
public class Person {
private Integer id;
private String name;
private Integer age;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
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;
}
@Override
public String toString() {
return "Person{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
'}';
}
}
部门类
public class Dept {
private String deptName;
private List personList;
public String getDeptName() {
return deptName;
}
public void setDeptName(String deptName) {
this.deptName = deptName;
}
public List getPersonList() {
return personList;
}
public void setPersonList(List personList) {
this.personList = personList;
}
@Override
public String toString() {
return "Dept{" +
"deptName='" + deptName + '\'' +
", personList=" + personList +
'}';
}
}
对象转为json字符串格式
JSON.toJSONString(Object object)
@Test
public void fun1(){
List personArrayList = new ArrayList();
Person person = new Person();
person.setId(1);
person.setName("张三");
person.setAge(18);
System.out.println(JSON.toJSONString(person));
personArrayList.add(person);
Person person1 = new Person();
person1.setId(2);
person1.setName("李四");
person1.setAge(18);
personArrayList.add(person1);
System.out.println(JSON.toJSONString(person1));
Dept dept = new Dept();
dept.setDeptName("财务部");
dept.setPersonList(personArrayList);
String jsonString = JSON.toJSONString(personArrayList);
System.out.println(jsonString);
}
JSON字符串转JavaBean
JSON.parseObject(String text,Class clazz)
@Test
public void fun2(){
String str1="{\"age\":18,\"id\":1,\"name\":\"张三\"}";
System.out.println(JSON.parseObject(str1,Person.class));
String str2="{\"age\":18,\"id\":2,\"name\":\"李四\"}";
System.out.println(JSON.parseObject(str2,Person.class));
}
JSON字符串数组转List集合
JSON.parseArray(String text, Class clazz)
@Test
public void fun3(){
String str="[{\"age\":18,\"id\":1,\"name\":\"张三\"},{\"age\":18,\"id\":2,\"name\":\"李四\"}]";
List PersonList=JSON.parseArray(str,Person.class);
System.out.println(PersonList);
}
Map集合转json
JSON.toJSONString(Object object)
@Test
public void fun4(){
Map personMap=new HashMap();
Person person = new Person();
person.setId(1);
person.setName("张三");
person.setAge(18);
personMap.put("zhangsan",person);
Person person1 = new Person();
person1.setId(2);
person1.setName("李四");
person1.setAge(18);
personMap.put("lisi",person1);
String json = JSON.toJSONString(personMap);
System.out.println(json);
}
MapJson字符串转Map集合
(Map)JSON.parse(Object object)
@Test
public void fun5(){
String str="{\"lisi\":{\"age\":18,\"id\":2,\"name\":\"李四\"},\"zhangsan\":{\"age\":18,\"id\":1,\"name\":\"张三\"}}";
Map map = (Map)JSONObject.parse(str);
System.out.println(map.get("lisi"));
System.out.println(map.get("zhangsan"));
}