java ftp文件上传详解

先我们来看两段简单的代码

将本地文件上传到ftp服务器上，代码如下：

 @test
 public void testuploadfromdisk(){
  try {
   fileinputstream in=new fileinputstream(new file("d:/test.txt"));
   boolean flag = uploadfile("127.0.0.1", 21, "test", "test", "d:/ftp", "test.txt", in);
   system.out.println(flag);
  } catch (filenotfoundexception e) {
   e.printstacktrace();
  }
 }

在ftp服务器上生成一个文件，并将一个字符串写入到该文件中

@test
 public void testuploadfromstring(){
  try {
   inputstream input = new bytearrayinputstream("test ftp".getbytes("utf-8"));
   boolean flag = uploadfile("127.0.0.1", 21, "test", "test", "d:/ftp", "test.txt", input);
   system.out.println(flag);
  } catch (unsupportedencodingexception e) {
   e.printstacktrace();
  }
 }

完整实例

import java.io.file;
import it.sauronsoftware.ftp4j.ftpclient;
import it.sauronsoftware.ftp4j.ftpfile;

public class javaftp {
private ftpclient client =null;
public void init(){
try {
client = new ftpclient();
client.connect("192.168.1.248", 21);
client.login("db2inst1", "db2inst1");
} catch (exception e) {
e.printstacktrace();
}
}
public static void main(string[] args) {
try {
javaftp javaftp=new javaftp();
javaftp.init();
javaftp.download("e://test", "/test/");
javaftp.close();
} catch (exception e) {
e.printstacktrace();
}
}
public void download(string localpath,string clientpath){
try {
if(clientpath!=null&&clientpath.length()>=0){
client.changedirectory(clientpath);
}
ftpfile[] list = client.list();

for(int i=0;i<list.length;i++){
ftpfile file = list[i];
system.out.println(file.gettype());
if(file.gettype()==ftpfile.type_directory){
file temp=new file(localpath+file.separator+file.getname());
if(!temp.exists()){
temp.mkdir();
}
download(localpath+file.separator+file.getname(),file.getname());
}
else if(file.gettype()==ftpfile.type_file){
file localfile=new file(localpath+file.separator+file.getname());
client.download(file.getname(), localfile);
}
}
} catch (exception e) {
e.printstacktrace();
}
}
public void close(){
try {
client.disconnect(true);
} catch (exception e) {
e.printstacktrace();
}
}
}

 从ftp服务器下载文件
 

* @version1.0 jul 27, 2008 5:32:36 pm by 崔红保（cuihongbao@d-heaven.com）创建
  * @param url ftp服务器hostname
  * @param port ftp服务器端口
  * @param username ftp登录账号
  * @param password ftp登录密码
  * @param remotepath ftp服务器上的相对路径
  * @param filename 要下载的文件名
  * @param localpath 下载后保存到本地的路径
  * @return
  */
 public static boolean downfile(string url, int port,string username, string password, string remotepath,string filename,string localpath) {
  boolean success = false;
  ftpclient ftp = new ftpclient();
  try {
   int reply;
   ftp.connect(url, port);
   //如果采用默认端口，可以使用ftp.connect(url)的方式直接连接ftp服务器
   ftp.login(username, password);//登录
   reply = ftp.getreplycode();
   if (!ftpreply.ispositivecompletion(reply)) {
    ftp.disconnect();
    return success;
   }
   ftp.changeworkingdirectory(remotepath);//转移到ftp服务器目录
   ftpfile[] fs = ftp.listfiles();
   for(ftpfile ff:fs){
    if(ff.getname().equals(filename)){
     file localfile = new file(localpath+"/"+ff.getname());
     
     outputstream is = new fileoutputstream(localfile);
     ftp.retrievefile(ff.getname(), is);
     is.close();
    }
   }
   
   ftp.logout();
   success = true;
  } catch (ioexception e) {
   e.printstacktrace();
  } finally {
   if (ftp.isconnected()) {
    try {
     ftp.disconnect();
    } catch (ioexception ioe) {
    }
   }
  }
  return success;
 }