Gson对Java嵌套对象和JSON字符串之间的转换

矫情吗；* 2022-06-10 04:53 207阅读 0赞

JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式，具有良好的跨平台特性。近几年来已经和XML一样成为C/S架构中广泛采用的数据格式。有关JSON的更多知识，请参考以下内容：http://json.org/json-zh.html

在服务器和客户端之间使用JSON数据格式进行通信，经常会涉及到JAVA对象和JSON字符串之间的转换。通常，我们可以使用一些JSON解析工具，例如：Gson，FastJson等。当然，我们也可以手动解析，只是会比较繁琐。

下面通过一个实例来介绍使用Gson来进行JAVA嵌套对象和JSON字符串之间的相互转换。

**实例工程下载：[http://download.csdn.net/download/yang\_hui1986527/4403352][http_download.csdn.net_download_yang_hui1986527_4403352]**

MainActivity

package com.example.jsonsample;
    
    import java.util.ArrayList;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.view.Menu;
    import android.widget.TextView;
    
    import com.example.jsonsample.data.Student;
    import com.example.jsonsample.data.Subject;
    import com.google.gson.Gson;
    
    public class MainActivity extends Activity {
    
        private TextView mTextView;
        
        
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            
            mTextView = (TextView)findViewById(R.id.MyTextView);
            
            Gson gson = new Gson();
            //创建一个学生对象        
            Student originStudent = getStudent();
            
            //将学生对象转换成JSON串
            String reponse = gson.toJson(originStudent);
            
            //将JSON串再还原成一个学生对象
            Student newstudent = gson.fromJson(reponse, Student.class);
    
            mTextView.setText(reponse);
        }
    
        public Student getStudent() {
            Subject sub1 = new Subject();
            sub1.setSubject_name("语文");
            sub1.setTeacher_name("张老师");
            
            Subject sub2 = new Subject();
            sub2.setSubject_name("数学");
            sub2.setTeacher_name("黄老师");  
            
            Subject sub3 = new Subject();
            sub3.setSubject_name("英文");
            sub3.setTeacher_name("林老师");  
            
            ArrayList<Subject> subjects = new ArrayList<Subject>();
            subjects.add(sub1);
            subjects.add(sub2);
            subjects.add(sub3);
            
            Student student = new Student();
            student.setName("杨辉");
            student.setSubjects(subjects);
    
            return student;
        }
        
        
        
    
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            getMenuInflater().inflate(R.menu.activity_main, menu);
            return true;
        }
    }

Student

package com.example.jsonsample.data;
    
    import java.io.Serializable;
    import java.util.ArrayList;
    /**
     * 学生类，包含学生名字和学科列表
     * 
     * @author yanghui<yanghui1986527@gmail.com>
     */
    public class Student implements Serializable {
    
        /**
         * Serializable
         */
        private static final long serialVersionUID = -2689979321936117293L;
        
        private String name;
        
        private ArrayList<Subject> subjects;
    
        /**
         * 
         * @return name 学生名字
         */
        public String getName() {
            return name;
        }
    
        /**
         * 
         * @param name 学生名字
         */
        public void setName(String name) {
            this.name = name;
        }
    
        /**
         * 
         * @return subjects 学科列表
         */
        public ArrayList<Subject> getSubjects() {
            return subjects;
        }
    
        /**
         * 
         * @param subjects 学科列表
         */
        public void setSubjects(ArrayList<Subject> subjects) {
            this.subjects = subjects;
        }
    
        
    }

Subject

package com.example.jsonsample.data;
    
    import java.io.Serializable;
    
    /**
     * 学科类，包含学科名字和学科老师名字
     * 
     * @author yanghui<yanghui1986527@gmail.com>
     */
    public class Subject implements Serializable{
    
    	/**
    	 * serialVersionUID
    	 */
    	private static final long serialVersionUID = -2574980011831897251L;
    
    	private String subject_name;
    	private String teacher_name;
    
    	/**
    	 * 
    	 * @return  subject_name 学科名称
    	 */
    	public String getSubject_name() {
    		return subject_name;
    	}
    
    	/**
    	 * @param  subject_name 学科名称
    	 */
    	public void setSubject_name(String subject_name) {
    		this.subject_name = subject_name;
    	}
    
    	/**
    	 *
    	 * @return  teacher_name 学科老师的名字
    	 */
    	public String getTeacher_name() {
    		return teacher_name;
    	}
    
    	/**
    	 * 
    	 * @param teacher_name 学科老师的名字
    	 */
    	public void setTeacher_name(String teacher_name) {
    		this.teacher_name = teacher_name;
    	}
    }

图片预览：

![1341047601_5233.png][]

[http_download.csdn.net_download_yang_hui1986527_4403352]: http://download.csdn.net/download/yang_hui1986527/4403352
[1341047601_5233.png]: https://img-my.csdn.net/uploads/201206/30/1341047601_5233.png