虽然android自带了json处理,但是没有封装,总觉得不方便,网上找了gson的处理,觉得还行。
//转换器 GsonBuilder builder = new GsonBuilder(); // 不转换没有 @Expose 注解的字段 builder.excludeFieldsWithoutExposeAnnotation(); Gson gson = builder.create(); //1、对象转string Student stu = new Student(); stu.setStudentId(333); stu.setStudentName("qqq"); String stuStr = gson.toJson(stu); System.out.println(stuStr); //{"studentName":"qqq","studentId":333} //2、string转对象 Student user2 = gson.fromJson(stuStr, Student.class); System.out.println(user2); String stuTemp = "{\"studentName\":\"qqq2\",\"studentId\":3335}"; Student user4 = gson.fromJson(stuTemp, Student.class); System.out.println(user4); //3、对象List转string List<Student> testBeanList = new ArrayList<Student>(); Student testBean = new Student(); testBean.setStudentId(555); testBean.setStudentName("552"); testBeanList.add(testBean); //Gson gsonList = new Gson(); Type type = new TypeToken<List<Student>>(){}.getType(); //指定集合对象属性 String beanListToJson = gson.toJson(testBeanList, type); System.out.println(beanListToJson); //[{"studentName":"552","studentId":555}] //集合string转对象list List<Student> testBeanListFromJson = gson.fromJson(beanListToJson, type); System.out.println(testBeanListFromJson); //[555:552] //4、集合如果不指定类型 默认为String List<String> testList = new ArrayList<String>(); testList.add("first"); testList.add("second"); String listToJson = gson.toJson(testList); System.out.println(listToJson); //["first","second"] //5、集合字符串转回来需要指定类型 List<String> testList2 = (List<String>) gson.fromJson(listToJson, new TypeToken<List<String>>() { }.getType()); System.out.println(testList2); //6、 将HashMap字符串转换为 JSON Map<String, String> testMap = new HashMap<String, String>(); testMap.put("id", "id.first"); testMap.put("name", "name.second"); String mapToJson = gson.toJson(testMap); System.out.println(mapToJson); //{"id":"id.first","name":"name.second"} //7、stringMap转对象 Map<String, String> userMap2 = (Map<String, String>) gson.fromJson(mapToJson, new TypeToken<Map<String, String>>() { }.getType()); System.out.println(userMap2); //{id=id.first, name=name.second} //8、对象含有普通对象、集合、map情况 Student user1 = new Student(); user1.setStudentId(1001); user1.setStudentName("张三"); Student user3 = new Student(); user3.setStudentId(1002); user3.setStudentName("李四"); Map<String, Student> userMap = new HashMap<String, Student>(); userMap.put("user1", user1); userMap.put("user3", user3); List<Student> userList = new ArrayList<Student>(); userList.add(user1); userList.add(user3); Teacher groupBean = new Teacher(); groupBean.setStudent(user1); groupBean.setStus(userList); groupBean.setMap((HashMap)userMap); //groupBean.setUserList(userList); Gson gsonGroup = new Gson(); String sGroupBean = gsonGroup.toJson(groupBean, new TypeToken<Teacher>() { }.getType()); System.out.println(sGroupBean); /*{"stus":[{"studentName":"张三","studentId":1001},{"studentName":"李四","studentId":1002}],"student":{"studentName":"张三","studentId":1001},"map":{"user3":{"studentName":"李四","studentId":1002},"user1":{"studentName":"张三","studentId":1001}},"id":0,"age":0}*/
//9、复杂对象string转对象 Teacher groupBean2 = (Teacher) gson.fromJson(sGroupBean, new TypeToken<Teacher>() { }.getType()); System.out.println(groupBean2);
package com.andtools; import com.google.gson.annotations.Expose; public class Student { @Expose private String studentName; @Expose private int studentId; public Student(){} public Student(int studentId,String studentName){ this.setStudentId(studentId); this.setStudentName(studentName); } public String toString(){ return this.getStudentId() + ":" + this.getStudentName(); } public String getStudentName() { return studentName; } public void setStudentName(String studentName) { this.studentName = studentName; } public int getStudentId() { return studentId; } public void setStudentId(int studentId) { this.studentId = studentId; } }
package com.andtools; import java.util.HashMap; import java.util.List; import java.util.Map; import com.google.gson.annotations.Expose; public class Teacher { @Expose private int id; @Expose private String name; @Expose private int age; @Expose private Student student; @Expose private List stus; @Expose private HashMap map; public String toString(){ return this.getId()+":"+this.getName()+":"+this.getAge() +":"+ this.getStudent().toString() + ":" + this.getStus() + ":" + this.getMap(); } 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; } public Student getStudent() { return student; } public void setStudent(Student student) { this.student = student; } public List getStus() { return stus; } public void setStus(List stus) { this.stus = stus; } public HashMap getMap() { return map; } public void setMap(HashMap map) { this.map = map; } }
附件为网上找的文档。