簡書手機版下載
做一個解析網站并將網站轉換為字符串的小應用，如下圖所示
運行結果.jpg
步驟如下：
1、UI布局
2、在MainActivity中
首先找到添加的控件
privatevoidfindViews(){? ? ? ? mEditText = (EditText) findViewById(R.id.editText);? ? ? ? mTextView = (TextView) findViewById(R.id.textView);? ? ? ? mButton = (Button) findViewById(R.id.button);? ? }
設置點擊事件
privatevoidsetListeners(){? ? ? ? mButton.setOnClickListener(this);? ? }
在onClick()事件中添加EditText網址的讀取
privateStringgetEditText(){returnmEditText !=null? mEditText.getText().toString() :"";? ? }
在onClick()事件中添加AsyncTask異步任務處理
classRequestNetworkDataTaskextendsAsyncTask{//在后臺work之前@Overrideprotectedvoid onPreExecute() {super.onPreExecute();//主線程//UI Loading}@OverrideprotectedStringdoInBackground(String[] params) {//請求網絡數據Stringresult = requestData(params[0]);returnresult;? ? ? ? }@Overrideprotectedvoid onPostExecute(Stringresult) {super.onPostExecute(result);//設置TextViewmTextView.setText(result);? ? ? ? }? ? }
請求網絡數據
privateStringrequestData(String urlString){try{? ? ? ? ? ? URL url =newURL(urlString);? ? ? ? ? ? HttpURLConnection connection = (HttpURLConnection) url.openConnection();? ? ? ? ? ? connection.setConnectTimeout(30000);? ? ? ? ? ? connection.setRequestMethod("GET");? ? ? ? ? ? connection.connect();intresponseCode = connection.getResponseCode();? ? ? ? ? ? String result =null;if(responseCode == HttpURLConnection.HTTP_OK) {? ? ? ? ? ? ? ? InputStream inputStream = connection.getInputStream();? ? ? ? ? ? ? ? Reader reader =newInputStreamReader(inputStream,"UTF-8");char[] buffer =newchar[1024];? ? ? ? ? ? ? ? reader.read(buffer);? ? ? ? ? ? ? ? result =newString(buffer);? ? ? ? ? ? }else{? ? ? ? ? ? }returnresult;? ? ? ? }catch(IOException e) {? ? ? ? ? ? e.printStackTrace();? ? ? ? }returnnull;? ? }
3、在AndroidManifest中添加網絡權限
完整項目代碼
packagecom.geekband.networkdemo;importandroid.os.AsyncTask;importandroid.support.v7.app.AppCompatActivity;importandroid.os.Bundle;importandroid.view.View;importandroid.widget.Button;importandroid.widget.EditText;importandroid.widget.TextView;importjava.io.IOException;importjava.io.InputStream;importjava.io.InputStreamReader;importjava.io.Reader;importjava.net.HttpURLConnection;importjava.net.URL;publicclassMainActivityextendsAppCompatActivityimplementsView.OnClickListener{privateEditText mEditText;privateButton mButton;privateTextView mTextView;@OverrideprotectedvoidonCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);? ? ? ? setContentView(R.layout.activity_main);? ? ? ? findViews();? ? ? ? setListeners();? ? }privatevoidsetListeners(){? ? ? ? mButton.setOnClickListener(this);? ? }privatevoidfindViews(){? ? ? ? mEditText = (EditText) findViewById(R.id.editText);? ? ? ? mButton = (Button) findViewById(R.id.button);? ? ? ? mTextView = (TextView) findViewById(R.id.textView);? ? }@OverridepublicvoidonClick(View v){switch(v.getId()) {caseR.id.button:? ? ? ? ? ? ? ? String url = getEditText();//申請網絡權限//? ? ? ? ? ? ? ? String data = requestData(url);newRequestNetworkDataTask().execute(url);break;? ? ? ? }? ? }privateStringgetEditText(){returnmEditText !=null? mEditText.getText().toString() :"";? ? }//異步任務處理classRequestNetworkDataTaskextendsAsyncTask{//在后臺work之前@OverrideprotectedvoidonPreExecute(){super.onPreExecute();//主線程//UI Loading}@OverrideprotectedStringdoInBackground(String[] params){//請求網絡數據String result = requestData(params[0]);returnresult;? ? ? ? }@OverrideprotectedvoidonPostExecute(String result){super.onPostExecute(result);//設置TextViewmTextView.setText(result);? ? ? ? }? ? }privateStringrequestData(String urlString){try{? ? ? ? ? ? URL url =newURL(urlString);? ? ? ? ? ? HttpURLConnection connection = (HttpURLConnection) url.openConnection();? ? ? ? ? ? connection.setConnectTimeout(30000);? ? ? ? ? ? connection.setRequestMethod("GET");? ? ? ? ? ? connection.connect();intresponseCode = connection.getResponseCode();? ? ? ? ? ? String result =null;if(responseCode == HttpURLConnection.HTTP_OK) {? ? ? ? ? ? ? ? InputStream inputStream = connection.getInputStream();? ? ? ? ? ? ? ? Reader reader =newInputStreamReader(inputStream,"UTF-8");char[] buffer =newchar[1024];? ? ? ? ? ? ? ? reader.read(buffer);? ? ? ? ? ? ? ? result =newString(buffer);? ? ? ? ? ? }else{? ? ? ? ? ? }returnresult;? ? ? ? }catch(IOException e) {? ? ? ? ? ? e.printStackTrace();? ? ? ? }returnnull;? ? }}
