java中ftp入门实例

mrmcggyloa

　　这几天学习Java中大文件上传的方法，先看了ftp的方式，网上搜索了一些资料，整理了一下。
　　首先：
　　在服务器端分配客户端登录用的用户名和密码，我用的是本地电脑，具体方式：

• 安装iis:我的是Windows XP系统，默认不安装IIS组件，需要手工添加安装。进入控制面板，找到“添加／删除程序”->“添加／删除Windows组件”->“Windows组件向导”->“Internet信息服务（IIS）”，勾上。再点击右下角的“详细信息”，在弹出的“Internet信息服务（IIS）”窗口中，找到“文件传输协议（FTP）服务”，选中后确定即可。
  
  安装完后需要重启。
  
• 设置账户：点击“开始→所有程序→管理工具→Internet信息服务”，进入“Internet信息服务”窗口后，找到“默认FTP站点”，右击鼠标，在弹出的右键菜单中选择“属性”。在“属性”中，我们可以设置FTP服务器的名称、IP、端口、访问账户、FTP目录位置、用户进入FTP时接收到的消息等。
  

• 想知道更多的信息可以度娘，谷哥……
  

　　然后：
　　然后就是代码了，建一个web项目，名字随意，在它下面建FtpApplet类，具体代码如下：

package ftpTest;
import sun.net.ftp.*;
import sun.net.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.io.*;
public class FtpApplet extends Applet {
FtpClient aftp;
DataOutputStream outputs;
TelnetInputStream ins;
TelnetOutputStream outs;
TextArea lsArea;
Label LblPrompt;
Button BtnConn;
Button BtnClose;
TextField TxtUID;
TextField TxtPWD;
TextField TxtHost;
int ch;
public String a = "没有连接主机";
String hostname = "";
public void init() {
setBackground(Color.white);
setLayout(new GridBagLayout());
GridBagConstraints GBC = new GridBagConstraints();
LblPrompt = new Label("没有连接主机");
LblPrompt.setAlignment(Label.LEFT);
BtnConn = new Button("连接");
BtnClose = new Button("断开");
BtnClose.enable(false);
TxtUID = new TextField("", 15);
TxtPWD = new TextField("", 15);
TxtPWD.setEchoCharacter('*');
TxtHost = new TextField("", 20);
Label LblUID = new Label("User ID:");
Label LblPWD = new Label("PWD:");
Label LblHost = new Label("Host:");
lsArea = new TextArea(30, 80);
lsArea.setEditable(false);
GBC.gridwidth = GridBagConstraints.REMAINDER;
GBC.fill = GridBagConstraints.HORIZONTAL;
((GridBagLayout) getLayout()).setConstraints(LblPrompt, GBC);
add(LblPrompt);
GBC.gridwidth = 1;
((GridBagLayout) getLayout()).setConstraints(LblHost, GBC);
add(LblHost);
GBC.gridwidth = GridBagConstraints.REMAINDER;
((GridBagLayout) getLayout()).setConstraints(TxtHost, GBC);
add(TxtHost);
GBC.gridwidth = 1;
((GridBagLayout) getLayout()).setConstraints(LblUID, GBC);
add(LblUID);
GBC.gridwidth = 1;
((GridBagLayout) getLayout()).setConstraints(TxtUID, GBC);
add(TxtUID);
GBC.gridwidth = 1;
((GridBagLayout) getLayout()).setConstraints(LblPWD, GBC);
add(LblPWD);
GBC.gridwidth = 1;
((GridBagLayout) getLayout()).setConstraints(TxtPWD, GBC);
add(TxtPWD);
GBC.gridwidth = 1;
GBC.weightx = 2;
((GridBagLayout) getLayout()).setConstraints(BtnConn, GBC);
add(BtnConn);
GBC.gridwidth = GridBagConstraints.REMAINDER;
((GridBagLayout) getLayout()).setConstraints(BtnClose, GBC);
add(BtnClose);
GBC.gridwidth = GridBagConstraints.REMAINDER;
GBC.fill = GridBagConstraints.HORIZONTAL;
((GridBagLayout) getLayout()).setConstraints(lsArea, GBC);
add(lsArea);
}
public boolean connect(String hostname, String uid, String pwd) {
this.hostname = hostname;
LblPrompt.setText("正在连接，请等待.....");
try {
aftp = new FtpClient(hostname);
aftp.login(uid, pwd);
aftp.binary();
showFileContents();
} catch (FtpLoginException e) {
a = "无权限与主机:" + hostname + "连接!";
LblPrompt.setText(a);
return false;
} catch (IOException e) {
a = "连接主机:" + hostname + "失败!";
LblPrompt.setText(a);
return false;
} catch (SecurityException e) {
a = "无权限与主机:" + hostname + "连接!";
LblPrompt.setText(a);
return false;
}
LblPrompt.setText("连接主机:" + hostname + "成功!");
return true;
}
public void stop() {
try {
aftp.closeServer();
} catch (IOException e) {
}
}
public void paint(Graphics g) {
}
public boolean action(Event evt, Object obj) {
if (evt.target == BtnConn) {
LblPrompt.setText("正在连接，请等待.....");
if (connect(TxtHost.getText(), TxtUID.getText(), TxtPWD.getText())) {
BtnConn.setEnabled(false);
BtnClose.setEnabled(true);
}
return true;
}
if (evt.target == BtnClose) {
stop();
BtnConn.enable(true);
BtnClose.enable(false);
LblPrompt.setText("与主机" + hostname + "连接已断开!");
return true;
}
return super.action(evt, obj);
}
public boolean sendFile(String filepathname) {
boolean result = true;
if (aftp != null) {
LblPrompt.setText("正在粘贴文件,请耐心等待....");
String contentperline;
try {
a = "粘贴成功!";
String fg = new String("\\");
int index = filepathname.lastIndexOf(fg);
String filename = filepathname.substring(index + 1);
File localFile;
localFile = new File(filepathname);
RandomAccessFile sendFile = new RandomAccessFile(filepathname,
"r");
//
sendFile.seek(0);
outs = aftp.put(filename);
outputs = new DataOutputStream(outs);
while (sendFile.getFilePointer() < sendFile.length()) {
ch = sendFile.read();
outputs.write(ch);
}
outs.close();
sendFile.close();
} catch (IOException e) {
a = "粘贴失败!";
result = false;
}
LblPrompt.setText(a);
showFileContents();
} else {
result = false;
}
return result;
}
public void showFileContents() {
StringBuffer buf = new StringBuffer();
lsArea.setText("");
try {
ins = aftp.list();
while ((ch = ins.read()) >= 0) {
buf.append((char) ch);
}
lsArea.appendText(buf.toString());
ins.close();
} catch (IOException e) {
}
}
public static void main(String args[]) {
Frame f = new Frame("FTP Client");
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
FtpApplet ftp = new FtpApplet();
ftp.init();
ftp.start();
f.add(ftp);
f.pack();
f.setVisible(true);
}
}