java - 寻找一种简单的方法来解析 JSON

Question

我正在尝试使用 Java 解析以下 JSON:

{ "student_id": "123456789", "student_name": "Bart Simpson", "student_absences": 1}

实现这一目标的最简单方法是什么？我尝试按照下面的方式进行操作，但认为一定有更简单的方法。

 import org.json.*
 JSONObject obj = new JSONArray("report");

 for(int i = 0; I < arr.length(); i++){
     String studentname =     
         arr.getJSONObject(i).getString("student_id");
         arr.getJSONObject(i).getString("student_name");
         arr.getJSONObject(i).getString("student_name");
 }

Answer 1

有Gson:

import com.google.gson.Gson;
import com.google.gson.annotations.SerializedName;

public class Main {
  public static void main(String[] args) {
    String json = "{ \"student_id\": \"123456789\", \"student_name\": \"Bart Simpson\", \"student_absences\": 1}";
    Student student = new Gson().fromJson(json, Student.class);
    System.out.println(student);
  }
}

class Student {

  @SerializedName("student_id")
  String studentId;

  @SerializedName("student_name")
  String studentName;

  @SerializedName("student_absences")
  Integer studentAbsences;

  @Override
  public String toString() {
    return "Student{" +
      "studentId='" + studentId + '\'' +
      ", studentName='" + studentName + '\'' +
      ", studentAbsences=" + studentAbsences +
      '}';
  }
}

另一个流行的是Jackson:

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;

public class Main {
  public static void main(String[] args) throws Exception {
    String json = "{ \"student_id\": \"123456789\", \"student_name\": \"Bart Simpson\", \"student_absences\": 1}";
    Student student = new ObjectMapper().readValue(json, Student.class);
    System.out.println(student);
  }
}

class Student {

  @JsonProperty("student_id")
  String studentId;

  @JsonProperty("student_name")
  String studentName;

  @JsonProperty("student_absences")
  Integer studentAbsences;

  @Override
  public String toString() {
    return "Student{" +
      "studentId='" + studentId + '\'' +
      ", studentName='" + studentName + '\'' +
      ", studentAbsences=" + studentAbsences +
      '}';
  }
}

在这两种情况下，运行 Main 将打印:

Student{studentId='123456789', studentName='Bart Simpson', studentAbsences=1}

编辑

在不创建 Student 类的情况下，您可以尝试一下 JsonPath 之类的东西。