Android JetPack学习总结（十一）

Json

依赖

dependencies {
  implementation 'com.google.code.gson:gson:2.8.6'
}

序列化

Student student1 =new Student("Jack",20);
Gson gson=new Gson();
String jsonStudent1=gson.toJson(student1);


Gson gson=new Gson();
        Student student1=new Student("Mike",20,new Score(90,80,70));
        Student student2=new Student("Lisa",21,new Score(91,81,71));
        Student[] students={student1,student2};
        String jsonStudents=gson.toJson(students);


Gson gson=new Gson();
        Student student1=new Student("Mike",20,new Score(90,80,70));
        Student student2=new Student("Lisa",21,new Score(91,81,71));
        List<Student> studentList=new ArrayList<>();
        studentList.add(student1);
        studentList.add(student2);
        String jsonStudents=gson.toJson(studentList);

反序列化

Gson gson=new Gson();
String jsonStudent1="{\"age\":20,\"name\":\"Jack\"}";
Student student1=gson.fromJson(jsonStudent1,Student.class);

Gson gson=new Gson();
        String jsonStudents="[{\"age\":20,\"name\":\"Mike\",\"score\":{\"Chinese\":70,\"English\":80,\"math\":90}},{\"age\":21,\"name\":\"Lisa\",\"score\":{\"Chinese\":71,\"English\":81,\"math\":91}}]";
        Student[] students=gson.fromJson(jsonStudents,Student[].class);




Gson gson=new Gson();
Score(91,81,71));
        List<Student> studentList=new ArrayList<>();
        String jsonStudents="[\n" +
                "  {\n" +
                "    \"age\": 20,\n" +
                "    \"name\": \"Mike\",\n" +
                "    \"score\": {\n" +
                "      \"Chinese\": 70,\n" +
                "      \"English\": 80,\n" +
                "      \"math\": 90\n" +
                "    }\n" +
                "  },\n" +
                "  {\n" +
                "    \"age\": 21,\n" +
                "    \"name\": \"Lisa\",\n" +
                "    \"score\": {\n" +
                "      \"Chinese\": 71,\n" +
                "      \"English\": 81,\n" +
                "      \"math\": 91\n" +
                "    }\n" +
                "  }\n" +
                "]";
        Type typeStudents=new TypeToken<List<Student>>(){}.getType();
        studentList=gson.fromJson(jsonStudents,typeStudents);

字段重命名

在类中添加@SerializedName(“student_name”)：

public class Student {
    @SerializedName("student_name")
    private String name;
    private int age;
    private Score score;
}

此时序列化结果name更名为student_name：

{
  "age": 20,
  "student_name": "Rose",
  "score": {
    "Chinese": 33,
    "English": 22,
    "math": 11
  }
}

序列化中忽略某字段

使用transient关键字。