- 创建一个URL对象： URL url = new URL(http://www.baidu.com);
- 调用URL对象的openConnection( )来获取HttpURLConnection对象实例： HttpURLConnection conn = (HttpURLConnection) url.openConnection();
- 设置HTTP请求使用的方法:GET或者POST，或者其他请求方式比如：PUT conn.setRequestMethod("GET");
- 设置连接超时，读取超时的毫秒数，以及服务器希望得到的一些消息头 conn.setConnectTimeout(6*1000);conn.setReadTimeout(6 * 1000);
- 调用getInputStream()方法获得服务器返回的输入流，然后输入流进行读取了 InputStream in = conn.getInputStream();
- 最后调用disconnect()方法将HTTP连接关掉 conn.disconnect();
StreamTool.java:
public class StreamTool { //从流中读取数据 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发送GET请求代码示例
获取数据类：GetData.java:
public class GetData { // 定义一个获取网络图片数据的方法: public static byte[] getImage(String path) throws Exception { URL url = new URL(path); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); // 设置连接超时为5秒 conn.setConnectTimeout(5000); // 设置请求类型为Get类型 conn.setRequestMethod("GET"); // 判断请求Url是否成功 if (conn.getResponseCode() != 200) { throw new RuntimeException("请求url失败"); } InputStream inStream = conn.getInputStream(); byte[] bt = StreamTool.read(inStream); inStream.close(); return bt; } // 获取网页的html源代码 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, "图片加载完毕", Toast.LENGTH_SHORT).show(); break; case 0x002: hideAllWidget(); scroll.setVisibility(View.VISIBLE); txtshow.setText(detail); Toast.makeText(MainActivity.this, "HTML代码加载完毕", Toast.LENGTH_SHORT).show(); break; case 0x003: hideAllWidget(); webView.setVisibility(View.VISIBLE); webView.loadDataWithBaseURL("", detail, "text/html", "UTF-8", ""); Toast.makeText(MainActivity.this, "网页加载完毕", Toast.LENGTH_SHORT).show(); break; default: break; } } ; }; @Override protected 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); } // 定义一个隐藏所有控件的方法: private void hideAllWidget() { imgPic.setVisibility(View.GONE); scroll.setVisibility(View.GONE); webView.setVisibility(View.GONE); } @Override // 重写上下文菜单的创建方法 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); } // 上下文菜单被点击是触发该方法 @Override public 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, "先请求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"> <TextView android:id="@+id/txtMenu" android:layout_width="match_parent" android:layout_height="48dp" android:background="#4EA9E9" android:clickable="true" android:gravity="center" android:text="长按我，加载菜单" android:textSize="20sp" /> <ImageView android:id="@+id/imgPic" android:layout_width="match_parent" android:layout_height="match_parent" android:visibility="gone" /> <ScrollView android:id="@+id/scroll" android:layout_width="match_parent" android:layout_height="match_parent" android:visibility="gone"> <TextView android:id="@+id/txtshow" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </ScrollView> <WebView android:id="@+id/webView" android:layout_width="match_parent" android:layout_height="match_parent" /> </LinearLayout>
最后别忘了加上联网权限：
<uses-permission android:name="android.permission.INTERNET" />
2）HttpURLConnection发送POST请求代码示例
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(); //设置请求方式,请求超时信息 conn.setRequestMethod("POST"); conn.setReadTimeout(5000); conn.setConnectTimeout(5000); //设置运行输入,输出: conn.setDoOutput(true); conn.setDoInput(true); //Post方式不能缓存,需手动设置为false conn.setUseCaches(false); //我们请求的数据: String data = "passwd="+ URLEncoder.encode(passwd, "UTF-8")+ "&number="+ URLEncoder.encode(number, "UTF-8"); //这里可以写一些请求头的东东... //获取输出流 OutputStream out = conn.getOutputStream(); out.write(data.getBytes()); out.flush(); if (conn.getResponseCode() == 200) { // 获取响应的输入流对象 InputStream is = conn.getInputStream(); // 创建字节输出流对象 ByteArrayOutputStream message = new ByteArrayOutputStream(); // 定义读取的长度 int len = 0; // 定义缓冲区 byte buffer[] = new byte[1024]; // 按照缓冲区的大小，循环读取 while ((len = is.read(buffer)) != -1) { // 根据读取的长度写入到os对象中 message.write(buffer, 0, len); } // 释放资源 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发送PUT请求
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; ; // 获取输出流: OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream()); writer.write(data); writer.flush(); writer.close(); // 获取相应流对象: 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")); // 资源释放: in.close(); // 返回字符串 Log.e("HEHE", response.toString()); return response.toString(); } catch (Exception e) { e.printStackTrace(); } return ""; }