Android使用网络技术

Android使用网络技术

1.WebView的用法

 <WebView
        android:id="@+id/web_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/&gt;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        WebView webview=(WebView) findViewById(R.id.web_view);
        webview.getSettings().setJavaScriptEnabled(true);
        webview.setWebViewClient(new WebViewClient());
        webview.loadUrl("http://www.baidu.com");
    }
}

AndroidManifest.xml授权

 <uses-permission android:name="android.permission.INTERNET"/&gt;

2.使用HTTP协议访问网络

1.使用HttpURLConnection

<Button
       android:id="@+id/send_request"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="Send Request"/&gt;
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"/&gt;
    <TextView
        android:id="@+id/response_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/&gt;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView reponseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest=(Button) findViewById(R.id.send_request);
        reponseText=(TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if(view.getId()==R.id.send_request){
            sendRequestWithHttpURLConnection();
        }
    }
    private void sendRequestWithHttpURLConnection(){
        //开启线程来发起网络请求
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection=null;
                BufferedReader reader=null;
                try {
                    URL url=new URL("https://www.baidu.com");
                    connection=(HttpURLConnection)url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    InputStream in=connection.getInputStream();
                    //下面对获取到的输入流进行读取
                    reader=new BufferedReader(new InputStreamReader(in));
                    StringBuilder response=new StringBuilder();
                    String line;
                    while ((line=reader.readLine())!=null){
                        response.append(line);
                    }
                    showResponse(response.toString());
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if(reader!=null){
                        try {
                            reader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if(connection!=null){
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }
    private void showResponse(final String response){
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                //在这里进行UI操作,将结果显示到界面上
                reponseText.setText(response);
            }
        });
    }
}

声明权限

<uses-permission android:name="android.permission.INTERNET"/>

如果想要使用post提交数据

connection.setRequestMethod("POST");
DataOutputStream out=new DataOutputStream(connection.getOutputStream());
out.writeBytes("username=admin&password=123456");

2.使用OkHttp

依赖库
implementation 'com.squareup.okhttp3:okhttp:4.1.0'

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView reponseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest=(Button) findViewById(R.id.send_request);
        reponseText=(TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if(view.getId()==R.id.send_request){
            sendRequestWithOKHttp();
        }
    }
    private void sendRequestWithOKHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client=new OkHttpClient();
                    Request request=new Request.Builder()
                            .url("http://www.baidu.com")
                            .build();
                    Response response=client.newCall(request).execute();
                    String responseData=response.body().string();
                    showResponse(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    private void sendRequestWithHttpURLConnection(){
        //开启线程来发起网络请求
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection=null;
                BufferedReader reader=null;
                try {
                    URL url=new URL("https://www.baidu.com");
                    connection=(HttpURLConnection)url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    InputStream in=connection.getInputStream();
                    //下面对获取到的输入流进行读取
                    reader=new BufferedReader(new InputStreamReader(in));
                    StringBuilder response=new StringBuilder();
                    String line;
                    while ((line=reader.readLine())!=null){
                        response.append(line);
                    }
                    showResponse(response.toString());
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if(reader!=null){
                        try {
                            reader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if(connection!=null){
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }
    private void showResponse(final String response){
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                //在这里进行UI操作,将结果显示到界面上
                reponseText.setText(response);
            }
        });
    }
}

3.解析XML格式数据

1.Pull解析方式

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView reponseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest=(Button) findViewById(R.id.send_request);
        reponseText=(TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if(view.getId()==R.id.send_request){
            sendRequestWithOKHttp();
        }
    }
    private void sendRequestWithOKHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client=new OkHttpClient();
                    Request request=new Request.Builder()
                            .url("http://10.0.2.2/get_data.xml")
                            .build();
                    Response response=client.newCall(request).execute();
                    String responseData=response.body().string();
                   parseXMLWithPull(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    private void parseXMLWithPull(String xmlData){
        try {
            XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
            XmlPullParser xmlPullParser=factory.newPullParser();
            //将服务器返回的XML数据设置进去,可以解析
            xmlPullParser.setInput(new StringReader(xmlData));
            //得到当前的解析事件
            int eventType=xmlPullParser.getEventType();
            String id="";
            String name="";
            String version="";
            //通过getName()方法得到当前节点的名字
            while (eventType!=XmlPullParser.END_DOCUMENT){
                String nodeName=xmlPullParser.getName();
                switch (eventType){
                    //开始解析某个节点
                    case XmlPullParser.START_TAG:{
                        if("id".equals(nodeName)){
                            id=xmlPullParser.nextText();
                        }else if ("name".equals(nodeName)){
                            name=xmlPullParser.nextText();
                        }else if("version".equals(nodeName)){
                            version=xmlPullParser.nextText();
                        }
                        break;
                    }
                    //完成解析某个节点
                        case XmlPullParser.END_TAG:{
                            if("app".equals(nodeName)){
                                Log.d("MainActivity","id is"+id);
                                Log.d("MainActivity","name is"+name);
                                Log.d("MainActivity","version is"+version);
                            }
                            break;
                        }
                    default:
                        break;
                }
                eventType=xmlPullParser.next();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

2.SAX解析方式

public class MyHandler extends DefaultHandler {
    //在开始XML解析的时候调用
    @Override
    public void startDocument() throws SAXException {
        super.startDocument();
    }
    //在开始解析某个节点的时候调用
    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        super.startElement(uri, localName, qName, attributes);
    }
    //在获取节点中内容的时候调用
    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        super.characters(ch, start, length);
    }
    //在完成解析某个结点的时候调用
    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        super.endElement(uri, localName, qName);
    }
    //在完成整个XML解析的时候调用
    @Override
    public void endDocument() throws SAXException {
        super.endDocument();
    }
}

public class ContentHandler extends DefaultHandler {
    private String nodeName;
    private StringBuilder id;
    private StringBuilder name;
    private StringBuilder version;
    @Override
    public void startDocument() throws SAXException {
        id = new StringBuilder();
        name = new StringBuilder();
        version = new StringBuilder();
    }

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        // 记录当前结点名
        nodeName = localName;
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        // 根据当前的结点名判断将内容添加到哪一个StringBuilder对象中
        if ("id".equals(nodeName)) {
            id.append(ch, start, length);
        } else if ("name".equals(nodeName)) {
            name.append(ch, start, length);
        } else if ("version".equals(nodeName)) {
            version.append(ch, start, length);
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        if ("app".equals(localName)) {
            Log.d("ContentHandler", "id is " + id.toString().trim());
            Log.d("ContentHandler", "name is " + name.toString().trim());
            Log.d("ContentHandler", "version is " + version.toString().trim());
            // 最后要将StringBuilder清空掉
            id.setLength(0);
            name.setLength(0);
            version.setLength(0);
        }
    }

    @Override
    public void endDocument() throws SAXException {
        super.endDocument();
    }

}

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView reponseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest=(Button) findViewById(R.id.send_request);
        reponseText=(TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if(view.getId()==R.id.send_request){
            sendRequestWithOKHttp();
        }
    }
    private void sendRequestWithOKHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client=new OkHttpClient();
                    Request request=new Request.Builder()
                            .url("http://10.0.2.2/get_data.xml")
                            .build();
                    Response response=client.newCall(request).execute();
                    String responseData=response.body().string();
                   parseXMLWithSAX(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    private void parseXMLWithSAX(String xmlData){
        try {
            SAXParserFactory factory = SAXParserFactory.newInstance();
            XMLReader xmlReader = factory.newSAXParser().getXMLReader();
            ContentHandler handler = new ContentHandler();
            // 将ContentHandler的实例设置到XMLReader中
            xmlReader.setContentHandler(handler);
            // 开始执行解析
            xmlReader.parse(new InputSource(new StringReader(xmlData)));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

4.解析JSON格式数据

1.使用JSONObject

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView reponseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest=(Button) findViewById(R.id.send_request);
        reponseText=(TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if(view.getId()==R.id.send_request){
            sendRequestWithOKHttp();
        }
    }
    private void sendRequestWithOKHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client=new OkHttpClient();
                    Request request=new Request.Builder()
                            .url("http://10.0.2.2/get_data.json")
                            .build();
                    Response response=client.newCall(request).execute();
                    String responseData=response.body().string();
                    parseJSONWithJSONObject(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    private void parseJSONWithJSONObject(String jsonData) {
        try {
            JSONArray jsonArray = new JSONArray(jsonData);
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                String id = jsonObject.getString("id");
                String name = jsonObject.getString("name");
                String version = jsonObject.getString("version");
                Log.d("MainActivity", "id is " + id);
                Log.d("MainActivity", "name is " + name);
                Log.d("MainActivity", "version is " + version);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

2.使用GSON

引入GSON依赖

 implementation 'com.google.code.gson:gson:2.8.5'

public class App {
    private String id;
    private String name;
    private String version;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getVersion() {
        return version;
    }

    public void setVersion(String version) {
        this.version = version;
    }
}

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView reponseText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button sendRequest=(Button) findViewById(R.id.send_request);
        reponseText=(TextView) findViewById(R.id.response_text);
        sendRequest.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if(view.getId()==R.id.send_request){
            sendRequestWithOKHttp();
        }
    }
    private void sendRequestWithOKHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client=new OkHttpClient();
                    Request request=new Request.Builder()
                            .url("http://10.0.2.2/get_data.json")
                            .build();
                    Response response=client.newCall(request).execute();
                    String responseData=response.body().string();
                    parseJSONWithGSON(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    private void parseJSONWithGSON(String jsonData) {
        Gson gson = new Gson();
        List<App> appList = gson.fromJson(jsonData, new TypeToken<List<App>>() {}.getType());
        for (App app : appList) {
            Log.d("MainActivity", "id is " + app.getId());
            Log.d("MainActivity", "name is " + app.getName());
            Log.d("MainActivity", "version is " + app.getVersion());
        }
    }
}

代码007普通

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