package com.android.fastjson.bean; 
public class Student { 
 private int id; 
 private String name; 
 private int age; 
 /** 
  * 默认的构造方法必须不能省，不然不能解析 
  */ 
 public Student(){ 
 } 
 public Student(int id,String name,int age) { 
  this.id = id; 
  this.name = name; 
  this.age = age; 
 } 
 public int getId() { 
  return id; 
 } 
 public void setId(int id) { 
  this.id = id; 
 } 
 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 "Student [id=" + id + ", name=" + name + ", age=" + age + "]"; 
 } 
} 

package com.android.fastjson.bean; 
import java.util.List; 
public class Teacher { 
 private int id; 
 private String name; 
 private List<Student> students; 
 /** 
  * 默认的构造方法必须不能省，不然不能解析 
  */ 
 public Teacher() { 
 } 
 public Teacher(int id,String name) { 
  this.id = id; 
  this.name = name; 
 } 
 public int getId() { 
  return id; 
 } 
 public void setId(int id) { 
  this.id = id; 
 } 
 public String getName() { 
  return name; 
 } 
 public void setName(String name) { 
  this.name = name; 
 } 
 public List<Student> getStudents() { 
  return students; 
 } 
 public void setStudents(List<Student> students) { 
  this.students = students; 
 } 
 @Override 
 public String toString() { 
  return "Teacher [id=" + id + ", name=" + name + ", mStudents=" 
    + students + "]"; 
 } 
} 

Student student = new Student(0, "Aaron", 24); 
  System.out.println(JSON.toJSONString(student)); 

List<Student> students = new ArrayList<Student>(); 
  for(int i=0;i<5;i++) { 
   Student stu = new Student(i, "Student" + i, 18 +i); 
   students.add(stu); 
  } 

[{"age":18,"id":0,"name":"Student0"},{"age":19,"id":1,"name":"Student1"},{"age":20,"id":2,"name":"Student2"},{"age":21,"id":3,"name":"Student3"},{"age":22,"id":4,"name":"Student4"}] 

List<Teacher> teaList = new ArrayList<Teacher>(); 
  long time = System.currentTimeMillis(); 
  for(int i=0;i<10;i++) { 
   Teacher teacher = new Teacher(i, "Teacher " + i); 
   List<Student> stus = new ArrayList<Student>(); 
   for(int j = 0 ;j<4;j++) { 
    Student s = new Student(j, "Student" + j, 18 +j); 
    stus.add(s); 
   } 
   teacher.setStudents(stus); 
   teaList.add(teacher); 
  } 
  String jsonTeach = JSON.toJSONString(teaList); 
  System.out.println("fastjson = " + jsonTeach); 

fastjson = [{"id":0,"name":"Teacher 0","students":[{"age":18,"id":0,"name":"Student0"},{"age":19,"id":1,"name":"Student1"}]},{"id":1,"name":"Teacher 1","students":[{"age":18,"id":0,"name":"Student0"},{"age":19,"id":1,"name":"Student1"}]},{"id":2,"name":"Teacher 2","students":[{"age":18,"id":0,"name":"Student0"},{"age":19,"id":1,"name":"Student1"}]},{"id":3,"name":"Teacher 3","students":[{"age":18,"id":0,"name":"Student0"},{"age":19,"id":1,"name":"Student1"}]}] 

Student student = new Student(0, "Aaron", 24); 
  System.out.println(JSON.toJSONString(student,true)); 

{ 
"age":24, 
"id":0, 
"name":"Aaron" 
} 

SimplePropertyPreFilter filter = new SimplePropertyPreFilter(Student.class, "id","age"); 
  String jsonStu =JSON.toJSONString(students,filter); 

Student student = new Student(0, "Aaron", 24); 
  String str = JSON.toJSONString(student,true); 
  System.out.println(JSON.parseObject(str,Student.class)); 

 List<Student> students = new ArrayList<Student>(); 
  for(int i=0;i<5;i++) { 
   Student stu = new Student(i, "Student" + i, 18 +i); 
   students.add(stu); 
  } 
  // 过滤哪些属性需要转换 
//  SimplePropertyPreFilter filter = new SimplePropertyPreFilter(Student.class, "id","age"); 
//  String jsonStu =JSON.toJSONString(students,filter); 
  String jsonStu =JSON.toJSONString(students); 
  System.out.println(jsonStu); 
   
  List<Student> stu =JSON.parseObject(jsonStu, new TypeReference<List<Student>>(){}); 
  for(int i=0;i<stu.size();i++) 
  { 
   System.out.println(stu.get(i)); 
  } 

Student [id=0, name=Student0, age=18] 
Student [id=1, name=Student1, age=19] 
Student [id=2, name=Student2, age=20] 
Student [id=3, name=Student3, age=21] 
Student [id=4, name=Student4, age=22]