Update UI.java

src/ftp/UI.java

 package ftp;
 
-public class UI {
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public  class UI extends JFrame  {
+
+    JButton jButton1 = new JButton("连接");
+    JButton jButton2 = new JButton("断开连接");
+    JButton jButton3 = new JButton("上传");
+    JButton jButton4 = new JButton("下载");
+
+    JTextField jTextField1 = new JTextField();
+    JTextField jTextField2 = new JTextField();
+    JTextField jTextField3 = new JTextField();
+    JPasswordField jPasswordField = new JPasswordField();
+    public  UI (){
+        setTitle("ftp软件");
+
+        setLayout(null);
+
+        setBounds(0,0,1000,700);
+
+        Container c = getContentPane();
+        JLabel jLabel1 = new JLabel("ip地址");
+        JLabel jLabel2 = new JLabel("端口号");
+        JLabel jLabel3 = new JLabel("用户名");
+        JLabel jLabel4 = new JLabel("密码");
+        jButton1.addActionListener(new jButton1event());
+        jButton2.addActionListener(new jButton2event());
+        jButton3.addActionListener(new jButton3event());
+        jButton4.addActionListener(new jButton4event());
+        jLabel1.setBounds(30,20,40,20);
+        jLabel2.setBounds(210,20,40,20);
+        jLabel3.setBounds(390,20,40,20);
+        jLabel4.setBounds(570,20,40,20);
+        jTextField1.setBounds(70,20,130,20);
+        jTextField2.setBounds(250,20,130,20);
+        jTextField3.setBounds(430,20,130,20);
+        jPasswordField.setBounds(610,20,130,20);
+        jButton1.setBounds(750,20,60,20);
+        jButton2.setBounds(820,20,100,20);
+        jButton3.setBounds(30,50,90,40);
+        jButton4.setBounds(170,50,90,40);
+
+
+        c.add(jLabel1);
+        c.add(jLabel2);
+        c.add(jLabel3);
+        c.add(jLabel4);
+        c.add(jTextField1);
+        c.add(jTextField2);
+        c.add(jTextField3);
+        c.add(jPasswordField);
+        c.add(jButton1);
+        c.add(jButton2);
+        c.add(jButton3);
+        c.add(jButton4);
+
+        setVisible(true);
+
+        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+
+
+    }
+
+    /*@Override
+    public void actionPerformed(ActionEvent e) {
+
+
+        if (e.getActionCommand() == "连接") {
+            if(jTextField1.getText()==null||jTextField2.getText()==""||jTextField3.getText()==""||jPasswordField.getText()==""){
+
+                JOptionPane .showMessageDialog(null,"输入不能为空","",JOptionPane.PLAIN_MESSAGE);
+
+            }
+            else{
+                //建立连接的代码
+            }
+
+
+        } else if (e.getActionCommand() == "断开连接") {//如果事件源是 jbClear,那么清除文本框的文字
+            //断开连接的代码
+        }
+    }*/
+    class jButton1event implements ActionListener{
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            String password=new String(jPasswordField.getPassword());
+
+            if(jTextField1.getText().trim().equals("")||jTextField2.getText().trim().equals("")||jTextField3.getText().trim().equals("")||password.trim().equals("")){
+
+                JOptionPane.showMessageDialog(null,"输入不能为空","",JOptionPane.PLAIN_MESSAGE);
+
+            }
+            else{
+                //建立连接的操作
+            }
+        }
+    }
+    class jButton2event implements ActionListener{
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            //断开连接的操作
+        }
+    }
+    class jButton3event implements ActionListener{
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            //上传操作
+        }
+    }
+    class jButton4event implements ActionListener{
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            //下载操作
+        }
+    }
+
+
+
+
+
+
 
 }