一个通过Socket或URLConnection传文件的示例

package com.net.demo; //Download by HTTP //For other protocol, do it yourself import java.net.*; import java.io.*; public class HttpDownLoad { public static void main(String args[]) { HttpDownLoad dl = new HttpDownLoad(); String downfile = "http://www.chinagps.cc/download/StormII_244.exe"; // can be any file type! Not only htm files can be downloaded. String saveplace = "d:\\temp\\StormII_244.exe"; if (dl.downLoadFile(downfile, saveplace)) System.out.println("下载完毕!"); if (dl.downLoadServerFile(downfile, "d:\\temp\\StormII_244_1.exe")) System.out.println("下载完毕!"); } public boolean downLoadFile(String fileurl, String savepath) { try { URL url = new URL(fileurl); URLConnection conn = url.openConnection(); InputStream is = conn.getInputStream(); int filelen = conn.getContentLength(); byte[] filebuf = new byte[filelen]; byte[] tmpbuf = new byte[1024]; int readcount = 0; int readnum = 0; while (readcount < filelen && readnum != -1) { readnum = is.read(tmpbuf); if (readnum > -1) { System.arraycopy(tmpbuf, 0, filebuf, readcount, readnum); readcount = readcount + readnum; } } if (readcount < filelen) { System.out.println("下载文件错误！"); return false; } File savefile = new File(savepath); if (!savefile.exists()) savefile.createNewFile(); FileOutputStream fos = new FileOutputStream(savefile); fos.write(filebuf); fos.close(); } catch (Exception e) { e.printStackTrace(); return false; } return true; } public boolean downLoadServerFile(String fileurl, String savepath) {//Things need to do: //Set connection timeout //Try more times to download //Catch a general Exception is not so good //... try { int httpStatusCode; URL url = new URL(fileurl); URLConnection conn = url.openConnection(); conn.connect(); HttpURLConnection httpconn = (HttpURLConnection) conn; httpStatusCode = httpconn.getResponseCode(); if (httpStatusCode != HttpURLConnection.HTTP_OK) {//HttpURLConnection return an error code System.out.println("连接 " + fileurl+ " 错误,返回的代码是:" + httpStatusCode); return false; } int filelen = conn.getContentLength(); InputStream is = conn.getInputStream(); byte[] tmpbuf = new byte[1024]; File savefile = new File(savepath); if (!savefile.exists()) savefile.createNewFile(); FileOutputStream fos = new FileOutputStream(savefile); int readnum = 0; if (filelen < 0)//for http://www.csdn.net/expert/topic/204/204361.shtm, conn.getContentLength() return -1. { while (readnum > -1) { readnum = is.read(tmpbuf); if (readnum > 0) fos.write(tmpbuf, 0, readnum); } } else { int readcount = 0; while (readcount < filelen && readnum != -1) { readnum = is.read(tmpbuf); if (readnum > -1) { fos.write(tmpbuf, 0, readcount); readcount = readcount + readnum; } } if (readcount < filelen) { System.out.println("下载错误"); is.close(); fos.close(); savefile.delete(); return false; } } fos.flush(); fos.close(); is.close(); } catch (Exception e) { e.printStackTrace(); return false; } return true; } }