使用，HttpURLConnection的使用步驟

• 創建一個URL對象：?URL url = new URL(http://www.baidu.com);
• 調用URL對象的openConnection( )來獲取HttpURLConnection對象實例：?HttpURLConnection conn = (HttpURLConnection) url.openConnection();
• 設置HTTP請求使用的方法:GET或者POST，或者其他請求方式比如：PUT?conn.setRequestMethod("GET");
• 設置連接超時，讀取超時的毫秒數，以及服務器希望得到的一些消息頭?conn.setConnectTimeout(6*1000);conn.setReadTimeout(6 * 1000);
• 調用getInputStream()方法獲得服務器返回的輸入流，然后輸入流進行讀取了?InputStream in = conn.getInputStream();
• 最后調用disconnect()方法將HTTP連接關掉?conn.disconnect();

StreamTool.java:

public class StreamTool {//從流中讀取數據public static byte[] read(InputStream inStream) throws Exception{ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len = 0;while((len = inStream.read(buffer)) != -1){outStream.write(buffer,0,len);}inStream.close();return outStream.toByteArray();}
}

1）HttpURLConnection發送GET請求代碼示例

獲取數據類：GetData.java:

public class GetData {// 定義一個獲取網絡圖片數據的方法:public static byte[] getImage(String path) throws Exception {URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();// 設置連接超時為5秒conn.setConnectTimeout(5000);// 設置請求類型為Get類型conn.setRequestMethod("GET");// 判斷請求Url是否成功if (conn.getResponseCode() != 200) {throw new RuntimeException("請求url失敗");}InputStream inStream = conn.getInputStream();byte[] bt = StreamTool.read(inStream);inStream.close();return bt;}// 獲取網頁的html源代碼public static String getHtml(String path) throws Exception {URL url = new URL(path);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("GET");if (conn.getResponseCode() == 200) {InputStream in = conn.getInputStream();byte[] data = StreamTool.read(in);String html = new String(data, "UTF-8");return html;}return null;}
}

MainActivity.java：

public class MainActivity extends AppCompatActivity {private TextView txtMenu, txtshow;private ImageView imgPic;private WebView webView;private ScrollView scroll;private Bitmap bitmap;private String detail = "";private boolean flag = false;private final static String PIC_URL = "http://ww2.sinaimg.cn/large/7a8aed7bgw1evshgr5z3oj20hs0qo0vq.jpg";private final static String HTML_URL = "http://www.baidu.com";// 用于刷新界面private Handler handler = new Handler() {public void handleMessage(android.os.Message msg) {switch (msg.what) {case 0x001:hideAllWidget();imgPic.setVisibility(View.VISIBLE);imgPic.setImageBitmap(bitmap);Toast.makeText(MainActivity.this, "圖片加載完畢", Toast.LENGTH_SHORT).show();break;case 0x002:hideAllWidget();scroll.setVisibility(View.VISIBLE);txtshow.setText(detail);Toast.makeText(MainActivity.this, "HTML代碼加載完畢", Toast.LENGTH_SHORT).show();break;case 0x003:hideAllWidget();webView.setVisibility(View.VISIBLE);webView.loadDataWithBaseURL("", detail, "text/html", "UTF-8", "");Toast.makeText(MainActivity.this, "網頁加載完畢", Toast.LENGTH_SHORT).show();break;default:break;}};};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);setViews();}private void setViews() {txtMenu = (TextView) findViewById(R.id.txtMenu);txtshow = (TextView) findViewById(R.id.txtshow);imgPic = (ImageView) findViewById(R.id.imgPic);webView = (WebView) findViewById(R.id.webView);scroll = (ScrollView) findViewById(R.id.scroll);registerForContextMenu(txtMenu);}// 定義一個隱藏所有控件的方法:private void hideAllWidget() {imgPic.setVisibility(View.GONE);scroll.setVisibility(View.GONE);webView.setVisibility(View.GONE);}@Override// 重寫上下文菜單的創建方法public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {MenuInflater inflator = new MenuInflater(this);inflator.inflate(R.menu.menus, menu);super.onCreateContextMenu(menu, v, menuInfo);}// 上下文菜單被點擊是觸發該方法
    @Overridepublic boolean onContextItemSelected(MenuItem item) {switch (item.getItemId()) {case R.id.one:new Thread() {public void run() {try {byte[] data = GetData.getImage(PIC_URL);bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);} catch (Exception e) {e.printStackTrace();}handler.sendEmptyMessage(0x001);};}.start();break;case R.id.two:new Thread() {public void run() {try {detail = GetData.getHtml(HTML_URL);} catch (Exception e) {e.printStackTrace();}handler.sendEmptyMessage(0x002);};}.start();break;case R.id.three:if (detail.equals("")) {Toast.makeText(MainActivity.this, "先請求HTML先嘛~", Toast.LENGTH_SHORT).show();} else {handler.sendEmptyMessage(0x003);}break;}return true;}
}

布局：activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><TextViewandroid:id="@+id/txtMenu"android:layout_width="match_parent"android:layout_height="48dp"android:background="#4EA9E9"android:clickable="true"android:gravity="center"android:text="長按我，加載菜單"android:textSize="20sp" /><ImageViewandroid:id="@+id/imgPic"android:layout_width="match_parent"android:layout_height="match_parent"android:visibility="gone" /><ScrollViewandroid:id="@+id/scroll"android:layout_width="match_parent"android:layout_height="match_parent"android:visibility="gone"><TextViewandroid:id="@+id/txtshow"android:layout_width="wrap_content"android:layout_height="wrap_content" /></ScrollView><WebViewandroid:id="@+id/webView"android:layout_width="match_parent"android:layout_height="match_parent" /></LinearLayout>

最后別忘了加上聯網權限：

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

2）HttpURLConnection發送POST請求代碼示例

使用？PostUtils.java

public class PostUtils {public static String LOGIN_URL = "http://172.16.2.54:8080/HttpTest/ServletForPost";public static String LoginByPost(String number,String passwd){String msg = "";try{HttpURLConnection conn = (HttpURLConnection) new URL(LOGIN_URL).openConnection();//設置請求方式,請求超時信息conn.setRequestMethod("POST");conn.setReadTimeout(5000);conn.setConnectTimeout(5000);//設置運行輸入,輸出:conn.setDoOutput(true);conn.setDoInput(true);//Post方式不能緩存,需手動設置為falseconn.setUseCaches(false);//我們請求的數據:String data = "passwd="+ URLEncoder.encode(passwd, "UTF-8")+"&number="+ URLEncoder.encode(number, "UTF-8");//這里可以寫一些請求頭的東東...//獲取輸出流OutputStream out = conn.getOutputStream();out.write(data.getBytes());out.flush();if (conn.getResponseCode() == 200) {  // 獲取響應的輸入流對象  InputStream is = conn.getInputStream();  // 創建字節輸出流對象  ByteArrayOutputStream message = new ByteArrayOutputStream();  // 定義讀取的長度  int len = 0;  // 定義緩沖區  byte buffer[] = new byte[1024];  // 按照緩沖區的大小，循環讀取  while ((len = is.read(buffer)) != -1) {  // 根據讀取的長度寫入到os對象中  message.write(buffer, 0, len);  }  // 釋放資源  
                    is.close();  message.close();  // 返回字符串  msg = new String(message.toByteArray());  return msg;}}catch(Exception e){e.printStackTrace();}return msg;}
}

3）使用HttpURLConnection發送PUT請求

public static String LoginByPut(Context mContext, String mobile, String password, int from, String devid,String version_name, int remember_me) {String resp = "";try {HttpURLConnection conn = (HttpURLConnection) new URL(LOGIN_URL).openConnection();conn.setRequestMethod("PUT");conn.setReadTimeout(5000);conn.setConnectTimeout(5000);conn.setDoOutput(true);conn.setDoInput(true);conn.setUseCaches(false);String data = "mobile=" + mobile + "&password=" + password + "&from=" + from + "&devid=" + "devid"+ "&version_name=" + "version_name" + "&remember_me=" + remember_me;;// 獲取輸出流:OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());writer.write(data);writer.flush();writer.close();// 獲取相應流對象:InputStream in = conn.getInputStream();BufferedReader reader = new BufferedReader(new InputStreamReader(in));StringBuilder response = new StringBuilder();String line;while ((line = reader.readLine()) != null)response.append(line);SPUtils.put(mContext, "session", conn.getHeaderField("Set-Cookie"));// 資源釋放:
        in.close();// 返回字符串Log.e("HEHE", response.toString());return response.toString();} catch (Exception e) {e.printStackTrace();}return "";
}

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