Android学习之JSON解析(二)使用GSON技术解析JSON-白红宇

前言

本人学生一枚，现阶段也是进行Android学习，若文章中有什么错误，请大l佬指出。

每篇格言:

我可以一落千丈，我偏要一鸣惊人。复制代码

用GSON框架技术解析JSON

GSON框架的官网:https://mvnrepository.com/artifact/com.google.code.gson/gson

如果使用Eclipse可发

选择相应版本的jar包进行下载复制代码

如果使用Android Studio开发

通过Gradle，直接添加以来，不用下载jar包复制代码

Gson解析JSON对象(介绍都在代码注释中)

重要的事说一遍：注意在使用Gson解析JSON对象时，记得创建JavaBean类，并且JavaBean类中的属性名要和JSON的key的名称相同，否则解析就会失败

JSON数据

{	"num": 1,	"age": 20,	"data": {		"chinese": 100,		"english": 90	}}复制代码

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结构：

重要的事说两遍：注意在使用Gson解析JSON对象时，记得创建JavaBean类，并且JavaBean类中的属性名要和JSON的key的名称相同，否则解析就会失败

Data

public class Data {    private int chinese;    private int english;    public int getChinese() {        return chinese;    }    public void setChinese(int chinese) {        this.chinese = chinese;    }    public int getEnglish() {        return english;    }    public void setEnglish(int english) {        this.english = english;    }    @Override    public String toString() {        return "Data{" +                "chinese=" + chinese +                ", english=" + english +                '}';    }}复制代码

重要的事说三遍：注意在使用Gson解析JSON对象时，记得创建JavaBean类，并且JavaBean类中的属性名要和JSON的key的名称相同，否则解析就会失败

Student

public class Student {    private int num;    private int age;    private Data data;    public int getNum() {        return num;    }    public void setNum(int num) {        this.num = num;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public Data getData() {        return data;    }    public void setData(Data data) {        this.data = data;    }    @Override    public String toString() {        return "Student{" +                "num=" + num +                ", age=" + age +                ", data=" + data +                '}';    }}复制代码

NetWorkUtils

public class NetWorkUtils {    private static HttpURLConnection sHttpURLConnection;    private static BufferedReader sBufferedReader;    private static InputStream sInputStream;    /**     * 通过URL获取String     *     * @param urlStr     需要传入的URL     * @param requestWay 需要传入的请求方式(GET/POST)     * @return 返货获取的json字符串     */    public static String sendUrlGetString(String urlStr, String requestWay) {        String jsonStr = null;        try {            // 创建URL对象            URL url = new URL(urlStr);            // 创建HttpURLConnection对象            sHttpURLConnection = (HttpURLConnection) url.openConnection();            // 设置网络的请求方式            sHttpURLConnection.setRequestMethod(requestWay);            // 设置链接主机超时            sHttpURLConnection.setConnectTimeout(8000);            // 设置从主机读取数据超时            sHttpURLConnection.setReadTimeout(8000);            // 获取输入流            sInputStream = sHttpURLConnection.getInputStream();            // 对获取到的输入流进行读取            sBufferedReader = new BufferedReader(new InputStreamReader(sInputStream));            StringBuffer stringBuffer = new StringBuffer();            String line = "";            while ((line = sBufferedReader.readLine()) != null) {                stringBuffer.append(line);            }            jsonStr = stringBuffer.toString();            return jsonStr;        } catch (MalformedURLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } finally {            if (sBufferedReader != null) {                try {                    sBufferedReader.close();                } catch (IOException e) {                    e.printStackTrace();                }            }            if (sHttpURLConnection != null) {                sHttpURLConnection.disconnect();            }        }        return jsonStr;    }}复制代码

MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private TextView mJsonTxt;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initViews();    }    private void initViews() {        Button gsonBtn = findViewById(R.id.gson_btn);        gsonBtn.setOnClickListener(this);        mJsonTxt = findViewById(R.id.json_txt);    }    @Override    public void onClick(View view) {        switch (view.getId()) {            case R.id.gson_btn:                new Thread(new Runnable() {                    @Override                    public void run() {                        paraseJSONWithGSON(NetWorkUtils.sendUrlGetString("http://xxx:8080/JsonThree", "GET"));                    }                }).start();                break;        }    }    private void paraseJSONWithGSON(final String str) {        runOnUiThread(new Runnable() {            @Override            public void run() {                // 创建一个Gson对象                Gson gson = new Gson();                // 调用Gson对象的fromJson(String str,Class
    
      class)                // 第一个参数 : 通过网络请求获取的JSON字符串                // 第二个参数 : 传入一个JavaBean对象                Student student = gson.fromJson(str, Student.class);                mJsonTxt.setText(student.toString());            }        });    }}复制代码

Gson解析JSON数组(介绍都在代码注释中)

JSON数据

[    {        "id": 1,        "name": "Amy",        "age": 20    },    {        "id": 2,        "name": "Tom",        "age": 10    }]复制代码

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People

public class People {    private int id;    private String name;    private int 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 "People{" +                "id=" + id +                ", name='" + name + '\'' +                ", age=" + age +                '}';    }}复制代码

MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private TextView mJsonTxt;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initViews();    }    private void initViews() {        Button gsonArrayBtn = findViewById(R.id.gsonArray_btn);        gsonArrayBtn.setOnClickListener(this);        mJsonTxt = findViewById(R.id.json_txt);    }    @Override    public void onClick(View view) {        switch (view.getId()) {            case R.id.gsonArray_btn:                new Thread(new Runnable() {                    @Override                    public void run() {                        paraseJSONWithGSONArray(NetWorkUtils.sendUrlGetString("http://XXX:8080/JsonTwo", "GET"));                    }                }).start();                break;        }    }    private void paraseJSONWithGSONArray(final String s) {        runOnUiThread(new Runnable() {            @Override            public void run() {                // 创建Gson对象                Gson gson = new Gson();                // 如果解析一段JSON数组会稍微麻烦点。我们需要借助TypeToken将期望解析成的数据类型传入到fromJson方法中。                List
    
      peopleList = gson.fromJson(s, new TypeToken
     
      
       >() {                }.getType());                for (People people : peopleList) {                    mJsonTxt.setText("id = " + people.getId() + "\n" + "name = " + people.getName() + "\n" + "age = " + people.getAge());                }            }        });    }}复制代码

总结

当然本篇文章中都是一些简单的JSON数据格式，适合入门学习，当然在实际开发中会很复杂的JSON数据格式，到时候大家见招拆招，不要死记解析步骤。复制代码