Java downloads files from the server and saves them locally

Yesterday in a project, the use of downloading files from the server and save to the local knowledge, has not been contacted, yesterday made a day, this small function realized, the following simple to say the implementation process;

1. Basic knowledge when we want to download a resource on the site, we get a URL, which is a description of the server location resource, the download process has the following steps: (1) The client initiates a URL request to get the connection object.           (2) The server resolves the URL, and returns the specified resource to the client with an input stream.           (3) Create a stored directory and a saved file name.           (4) Output the write data.     (5) Close the input stream and the output stream. 2. Ways to implement Code

/** * @ feature Download temporary footage interface * @param filePath file will be saved directory * @param method request methods, including post and get * @param URL Request path * @return */ public static File Saveurlas (String url,string filepath,string method) {//system.out.println ("fileName---->" +       FilePath);       Create a different folder directory file File=new file (FilePath);      Determine if the folder exists if (!file.exists ()) {//If the folder does not exist, create a new folder File.mkdirs ();       } FileOutputStream fileout = null;       HttpURLConnection conn = null;       InputStream inputstream = null;           try {//Establish link URL httpurl=new url (url);           Conn= (HttpURLConnection) httpurl.openconnection ();           Submit form by post, default get Mode Conn.setrequestmethod (method);             Conn.setdoinput (TRUE);           Conn.setdooutput (TRUE);           Post mode cannot use cache conn.setusecaches (false);           Connect the specified resource Conn.connect ();           Get the network input stream Inputstream=conn.getinputstream (); BuffEredinputstream bis = new Bufferedinputstream (InputStream);                 Determines whether the file's save path is followed by/ending if (!filepath.endswith ("/")) {FilePath + = "/";           }//write to the file (note that the file name must be appended to the path to save files) Fileout = new FileOutputStream (filepath+ "123.png");                      Bufferedoutputstream BOS = new Bufferedoutputstream (fileout);           byte[] buf = new byte[4096];           int length = Bis.read (BUF);               Save file while (length! =-1) {bos.write (buf, 0, length);           Length = Bis.read (BUF);           } bos.close ();           Bis.close ();      Conn.disconnect ();           } catch (Exception e) {e.printstacktrace (); System.out.println ("Throw an exception!!      ");          } return file;   }

　　

3. Code test Class (main function)

/**       * @param args       *      /public static void main (string[] args)      {          String photourl = "https:// Ss0.bdstatic.com/5av1bjqh_q23odcf/static/superman/img/logo/bd_logo1_31bdc765.png ";                                              String fileName = photourl.substring (Photourl.lastindexof ("/"));           System.out.println ("fileName---->" +filename);          String FilePath = "D:";            File File = Saveurlas (Photourl, FilePath + fileName, "GET");            System.out.println ("Run ok!/n<br>get URL File" + file);          }  

　　

Java downloads files from the server and saves them locally