用java的.net包和http的post实现upload和download- -

用java的.net包和http的post实现upload和download- -

                                      

　　用java的.net包和http的post实现upload和download。需要用到的对象有URL, HttpURLConnection, OutputStreamWriter等．下面给出源码： 

1.文件上传：

HttpURLConnection conn = null;BufferedWriter bWriter = null;OutputStream os = null;OutputStreamWriter osw = null;String strData = "filename=postest.txt&data=1234566778888";try {URL url1 = new URL("http://yoururl/upload.php");conn = (HttpURLConnection)url1.openConnection();conn.setRequestMethod("POST");conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");conn.setRequestProperty("Connection", "Keep-Alive");conn.setUseCaches( false);conn.setDoOutput(true);osw = new OutputStreamWriter(conn.getOutputStream());osw.write("filename=postest.txt&data=1234567890");osw.flush() ;osw.close() ;if (conn.getResponseCode() != HttpURLConnection.HTTP_OK)System.out.println( "connect failed!");}catch (Exception e) {e.printStackTrace(System.out);}finally{if (osw != null)try {osw.close() ;} catch (IOException e1) {e1.printStackTrace(System.out);}if (conn != null)conn.disconnect() ;}php根据上传数据写文件的代码（一些额外的代码都被去掉了）：if($data!=""){$path="filepath/".trim($filename);$fp = fopen($path,"a");if($fp){flock($fp,2);$fw=fputs($fp,$data);fclose($fp);Header("Location: http://yourhost/succes.php");}else{Header("Location: http://yourhost/error.php");}}else{Header("Location: http://yourhost/error.php");}

2.文件下载：

HttpURLConnection conn = null;RandomAccessFile f=null;InputStream is = null;int contentlength = 0;int spos = 0;int epos = 0;int nread = 0;try{URL url1 = new URL("yoururl/download.rar");conn = (HttpURLConnection)url1.openConnection();conn.setRequestMethod("GET");conn.setRequestProperty("User-Agent", "NetFox");conn.setRequestProperty("Connection", "Keep-Alive");for (int i=1;; i++){String head = conn.getHeaderFieldKey(i);if (head == null)break;System.out.println(head+": "+ conn.getHeaderField(head));}epos = contentlength = conn.getContentLength() ;is = conn.getInputStream();int unitsize = contentlength<1024?contentlength:1024;byte[] b = new byte[unitsize];f = new RandomAccessFile("C:/eclipse/workspace/pgtest/download/posttest.rar", "rw");System.out.println("Receive data beginning:");while ((nread=is.read(b, 0, unitsize))>0 && spos小于epos){f.write(b);spos += unitsize;System.out.println("has received bytes:" + spos);}}catch (FileNotFoundException fnfe){System.out.println("file " + f.toString() + " is not found.");} catch (Exception e) {e.printStackTrace(System.out);}finally{if (f != null)try {f.close() ;} catch (IOException e1) {e1.printStackTrace(System.out);}if (is != null)try {is.close();} catch (IOException ioe) {ioe.printStackTrace(System.out);}if (conn != null)conn.disconnect() ;}System.out.println("download success!");

From:

http://jimjava.bokee.com/414949.html