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// get 请求，取得响应public class GetRunnable implements Runnable { private Handler myhand; public MyRunnable(Handler hand) { this.myhand = hand; } @Override public void run() { // http://192.168.1.29:8080/itheima83/servlet/LoginServlet?username=sdafsad&pwd=fsadf String message = ""; try { URL url = new URL("http://192.168.1.29:8080/itheima83/servlet/LoginServlet?username=sdafsad&pwd=fsadf"); HttpURLConnection http = (HttpURLConnection) url.openConnection(); http.setConnectTimeout(10000); http.setRequestMethod("GET"); int status = http.getResponseCode(); if (status < 300) { InputStream is = http.getInputStream(); ByteArrayOutputStream bos = new ByteArrayOutputStream(); byte[] buffer = new byte[1024 * 10]; int len = 0; while ((len = is.read(buffer)) != -1) { bos.write(buffer, 0, len); } message = bos.toString(); bos.close(); } Message msg = new Message(); msg.obj = message; myhand.sendMessage(msg); } catch (Exception e) { e.printStackTrace(); } }} // post 请求，取得响应 URL url = new URL("http://192.168.1.29:8080/itheima83/servlet/LoginServlet"); HttpURLConnection http = (HttpURLConnection) url.openConnection(); http.setConnectTimeout(10000); http.setRequestMethod("POST"); http.setDoOutput(true); //下面两行，不加同样可以被服务器解析。最好加上。 http.setRequestProperty("Content-type", "application/x-www-form-urlencoded");// multipart/form-data http.setRequestProperty("Content-Length", content.length()+""); http.getOutputStream().write("username=sdafsad&pwd=fsadf".getBytes()); int status = http.getResponseCode(); if (status < 300) { //获得输入流，进行读取使用 } // post 提交文件 一般不用这个，因为post提交的标准请求体格式不好包装。尤其是 multipart类型的包装。 这个包装包括请求头的 content的长度，编码等内容。。 当然，如果自己写服务端，就无所谓了。 //下载。这个没什么总结的。通过无论什么请求，服务器把响应返回。 //响应包含响应头，里面有文件大小等信息 //单线程下载，多线程下载 //多线程的 Range 请求。和 content-Length的平均startIndex，endIndex。 // 断点续传，记录下载的位置点 class MyRunnable implements Runnable{ private String url_st; private String file_path; private int start; private int end; public MyRunnable(String url_st, String file_path, int start, int end) { this.url_st = url_st; this.file_path = file_path; this.start = start; this.end = end; System.out.println(">>>>>>>>>开启一个新的线程。start:"+start+" end:"+end); } @Override public void run() { if(cacheFile.exsit()){ FileInputStream fileInputStream = new FileInputStream(file3); BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(fileInputStream)); lastSaveIndex = Integer.parseInt(bufferedReader.readLine();); } try { URL url = new URL(url_st); HttpURLConnection http = (HttpURLConnection) url.openConnection(); http.setRequestMethod("GET"); http.setRequestProperty("Range", "bytes="+start+"-"+end); http.setConnectTimeout(10000); //开始写 InputStream is = http.getInputStream(); RandomAccessFile raf = new RandomAccessFile(file_path,"rwd"); raf.seek(start); byte[] buffer = new byte[1024*10]; int len =0; while((len = is.read(buffer)) != -1){ raf.write(buffer, 0, len); //标记写的位置，可以用来续传 File file2 = new File( getdownloadPath()+threadId+".txt"); RandomAccessFile randomAccessFile2 = new RandomAccessFile(file2, "rwd"); randomAccessFile2.write(String.valueOf(currentThreadDownloadPosition).getBytes()); randomAccessFile2.close(); //利用 progressbard 的引用。改变 progressbar 的进度。 progressBar2.setProgress(progress); } raf.close(); http.disconnect(); } catch (MalformedURLException e) { e.printStackTrace(); }catch(IOException e){ e.printStackTrace(); } }} 转载地址：http://pbegi.baihongyu.com/