java 从服务器下载_Java从web服务器下载文件到本地

/*从服务器中下载文件到本地*/

/*url:文件存放在服务器的地址；target:要保存的路径*/

public String DownloadFile(String url,String target){

URLConnection con=null;

URL theUrl=null;

try {

theUrl=new URL(url);//建立地址

con = theUrl.openConnection();//打开连接

con.setConnectTimeout(30000);

con.connect();//连接

} catch (MalformedURLException e) {

Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, e);

return "给定的URL地址有误，请查看";

}

catch (IOException e) {

Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, e);

return "无法连接到远程机器，请重试！";

}

jLabel5.setText("√");

Process++;

File file = new File(gbl_ParentPath+"/UpdateTemp");

if(file.exists()==false){

file.mkdir();

}

String type = con.getContentType();

if (type != null) {

byte[] buffer = new byte[4 * 1024];

int read;

try {

FileOutputStream os = new FileOutputStream(target);

InputStream in = con.getInputStream();//重定向输入

while ((read = in.read(buffer)) > 0) {//读取输出

os.write(buffer, 0, read);//写入本地文件

}

os.close();

in.close();

jLabel6.setText("√");

Process++;

} catch (FileNotFoundException e) {

Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, e);

return "所要下载的文件不存在！";

}catch (IOException e) {

Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, e);