java 简单实用的文件下载代码
package wan.url.download; import java.io.File; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.URL; public class FileDownLoad{ public static void main(String[] args) throws Exception { String str="http://www.itconcept.com.hk/mp3/d21.mp3"; DownLoad dl=new DownLoad(str); dl.downLoadBinaryFile(); } } class DownLoad { private String url; public DownLoad(String url){ this.url=url;} public void downLoadBinaryFile(){ try{ URL myurl=new URL(url); HttpURLConnection httpConnect=(HttpURLConnection)myurl.openConnection(); httpConnect.connect(); if(httpConnect.getResponseCode()==HttpURLConnection.HTTP_OK){ InputStream in=httpConnect.getInputStream(); long size=httpConnect.getContentLengthLong(); String[] names=myurl.getFile().split("/"); String name=names[names.length-1]; File dir=new File("h:/temp"); if(!dir.isDirectory()) dir.mkdirs(); File file=new File(dir.getPath()+"/"+name); if(file.exists()) { System.out.println("File is Exists!!!!"); return; } else{ file.createNewFile(); OutputStream out=new FileOutputStream(file); while(file.length()!=size){ byte[] buf=new byte[1024]; int count=0; while((count=in.read(buf))!=-1) out.write(buf, 0, count); } in.close(); out.close();} System.out.println("Download Success!"); } else System.out.println("Connecting error"); }catch(Exception e){ new RuntimeException("DownLoad failed ,please try again"); } } }