package Student_system;   import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.io.*; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.Statement; import java.util.*; /*class Stu implements java.io.Serializable{  String number,name,specialty,grade,borth,sex;  public Stu(){};  public void setNumber(String number){ this.number=number;}  public String getNumber(){ return number;}  public void setName(String name){ this.name=name;}  public String getName(){ return name;}  public void setSex(String sex){ this.sex=sex;}  public String getSex(){ return sex;}  public void setSpecialty(String specialty){ this.specialty=specialty;}  public String getSpecialty(){ return specialty;}  public void setGrade(String grade){ this.grade=grade;}  public String getGrade(){ return grade;}  public void setBorth(String borth){ this.borth=borth;}  public String getBorth(){ return borth;} }*/  public class StudentSystem extends JFrame{  public static void main(String[] args){   JFrame frame = new JFrame();   frame.setTitle("信息管理系統");   frame.setSize(500, 500);   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   Container container = frame.getContentPane();   container.setLayout(new FlowLayout());  JLabel lb=new JLabel("錄入請先輸入記錄，查詢、刪除請先輸入學號，修改是對查詢" +    "內容改后的保存！");  final JTextField 學號; final JTextField 姓名; final JTextField 專業; final JTextField 年級; final JTextField 出生;  final JRadioButton 男; final JRadioButton 女;  ButtonGroup group=null;  JButton 錄入,查詢,刪除,修改,顯示;  JPanel p1,p2,p3,p4,p5,p6,pv,ph;  學號=new JTextField(10);  姓名=new JTextField(10);  專業=new JTextField(10);  年級=new JTextField(10);  出生=new JTextField(10);  group=new ButtonGroup();  男=new JRadioButton("男");  女=new JRadioButton("女");  group.add(男);  group.add(女);  錄入=new JButton("錄入");  查詢=new JButton("查詢");  刪除=new JButton("刪除");  修改=new JButton("修改");  顯示=new JButton("顯示");  修改.setEnabled(false);    //添加輸入框及文本框  p1=new JPanel();  p1.add(new JLabel("學號:",JLabel.CENTER));  p1.add(學號);  p2=new JPanel();  p2.add(new JLabel("姓名:",JLabel.CENTER));  p2.add(姓名);  p3=new JPanel();  p3.add(new JLabel("性別:",JLabel.CENTER));  p3.add(男);  p3.add(女);  p4=new JPanel();  p4.add(new JLabel("專業:",JLabel.CENTER));  p4.add(專業);  p5=new JPanel();  p5.add(new JLabel("年級:",JLabel.CENTER));  p5.add(年級);  p6=new JPanel();  p6.add(new JLabel("出生:",JLabel.CENTER));  p6.add(出生);  pv=new JPanel();  pv.setLayout(new GridLayout(6,1));  pv.add(p1);  pv.add(p2);  pv.add(p3);  pv.add(p4);  pv.add(p5);  pv.add(p6);  ph=new JPanel();  ph.add(錄入);  ph.add(查詢);  ph.add(修改);  ph.add(刪除);  ph.add(顯示);  frame.add(lb);  frame.add(ph);  frame.add(p1);  frame.add(p2);  frame.add(p3);  frame.add(p4);  frame.add(p5);  frame.add(p6);  frame.add(pv);  frame.add(ph);     class MyListener implements ActionListener {   public void actionPerformed (ActionEvent e) {            //判斷選中是男是女     /*if(e.getSource().equals(男)){      if(男.isSelected()) {       System.out.println("男被選中了");      } else {       System.out.println("男被取消選中了");      }     }         if(e.getSource().equals(女)){      if(女.isSelected()) {       System.out.println("女被選中了");      } else {       System.out.println("女被取消選中了");      }     }*/        //錄入 的功能    if(e.getActionCommand() == "錄入") {          String text1 = 學號.getText().trim();     String text2 = 姓名.getText();     String text3 = 專業.getText();     String text4 = 年級.getText();     String text5 = 出生.getText();     String text6 = null;     String text7 = "- - - - -我是分割線 - - - - -";     if(男.isSelected()) {      text6 = "男";     }          if(女.isSelected()) {      text6 = "女";     }               //用texts包含此次所有錄入信息     String texts = "/n/n學號：" + text1 + "/n/n" + "姓名：" + text2 + "/n/n" + "專業：" + text3 + "/n/n" + "年級：" + text4 + "/n/n" + "出生：" + text5 + "/n/n" + "性別：" + text6 + "/n/n" ;          //顯示框     int m = JOptionPane.showConfirmDialog(null, "是否錄入該條記錄：" + texts , "錄入" , JOptionPane.YES_NO_OPTION);//n = 1/0;     if(m==0) {      insert_Student(text1,text2,text3,text4,text5);           } else {      JOptionPane.showMessageDialog(null, "已取消該次錄入??！");     }    }        //顯示 的功能    if(e.getActionCommand() == "顯示") {               int n = JOptionPane.showConfirmDialog(null, "是否顯示所有記錄" , "顯示" , JOptionPane.YES_NO_OPTION);//n = 1/0;          if(n ==0 ) {     try {            File file = new File("D:/file.txt");      InputStreamReader reader = new InputStreamReader(        new FileInputStream(file));//創建一個輸入流對象            BufferedReader bufferReader = new BufferedReader(reader);            String line = "";      String lines = null;      line = bufferReader.readLine();      while(line != null) {              System.out.println(line);       if(lines != null) {       lines = lines + "/n" + line + "/n";       } else {        lines = line + "/n" ;       }       line = bufferReader.readLine();      }      //JOptionPane.showMessageDialog(null, lines , "顯示",JOptionPane.INFORMATION_MESSAGE);           } catch (Exception e1) {      e1.printStackTrace();     }     } else {      JOptionPane.showMessageDialog(null, "已取消該次查詢");     }         }        //查詢 的功能    if(e.getActionCommand() == "查詢") {     File file = new File("D:/file.txt");     BufferedReader reader = null;     String text7 = "- - - - -我是分割線 - - - - -";     try {            //InputStreamReader reader = new InputStreamReader(       // new FileInputStream(file));//創建一個輸入流對象             reader = new BufferedReader(new FileReader(file));            //暫時僅允許查詢學號      String text1 = 學號.getText();      int n = JOptionPane.showConfirmDialog(null, "查詢的學號為：" + text1 , "查詢" , JOptionPane.YES_NO_OPTION);//n = 1/0;      if(n == 0){      String line = null;      String lines = null;            while((line = reader.readLine())!= null) {        if(line.equals(text1)) {        System.out.println(line);        while(!(line.equals(text7))){         line = reader.readLine();         if(lines == null) {          lines = line + "/n";         } else {          lines = lines + line + "/n";         }        System.out.println(line);        }                } else {         continue;        }                     }      JOptionPane.showMessageDialog(null, lines , "查詢",JOptionPane.INFORMATION_MESSAGE);      reader.close();      } else {       JOptionPane.showMessageDialog(null, "已取消查詢功能");      }     } catch (Exception e1) {      e1.printStackTrace();     } finally {      if(reader != null) {       try {        reader.close();       }catch (IOException e1){               }      }     }    }            //刪除 的功能    if(e.getActionCommand() == "刪除") {     String text1 = 學號.getText().trim();     delete_Student(text1);    }       }   }   //------------注冊監聽-------------    MyListener listener = new MyListener();  MyListener listen = new MyListener();  顯示.addActionListener(listener);  錄入.addActionListener(listener);  查詢.addActionListener(listener);  刪除.addActionListener(listener);  男.addActionListener(listen);  女.addActionListener(listen);  frame.setVisible(true);  }    /*   * ---------------------- 功能函數 ---------------------  */     //獲取所有的數據  //  public static void getAllMessage(){  try {   //添加JDBC驅動   Class.forName("com.mysql.jdbc.Driver");   String url = "jdbc:mysql://localhost/test";   String user = "root";   String password = "root";   Connection connect = DriverManager.getConnection(url,user,password);   Statement stmt = connect.createStatement();   System.out.println("success to connect ");      //讀取所有的數據       String sql1 = "select * from StudentSystem";   ResultSet rs = stmt.executeQuery(sql1);   System.out.println("學號/t姓名/t專業/t年級/t出生");   String lines = null;   while(rs.next()) {    System.out.print(rs.getString(1)+ "/t");    System.out.print(rs.getString(2)+ "/t");    System.out.print(rs.getString(3)+ "/t");    System.out.print(rs.getString(4)+ "/t");    System.out.print(rs.getString(5)+ "/t");    System.out.println();    if(lines != null){    lines = lines + "學號__姓名__專業__年級__出生/n" + rs.getString(1)+ "  "+ rs.getString(2)+ "  "+ rs.getString(3)      + " "+ rs.getString(4)+ "  "+ rs.getString(5)+ "   " + "/n/n";    } else {     lines ="數據庫中所有數據：/n/n" + "學號__姓名__專業__年級__出生/n" + rs.getString(1)+ ""+ rs.getString(2)+ " "+ rs.getString(3)       + "  "+ rs.getString(4)+ "   "+ rs.getString(5)+ " " + "/n";    }   }   JOptionPane.showMessageDialog(null, lines , "顯示",JOptionPane.INFORMATION_MESSAGE);    } catch (Exception e) {   e.printStackTrace();  }    }    /**   * 插入功能   */     public static void insert_Student(String str1,String str2,String str3,String str4,String str5){    try {     //添加JDBC驅動     Class.forName("com.mysql.jdbc.Driver");     String url = "jdbc:mysql://localhost/test";     String user = "root";     String password = "root";     //連接數據庫     Connection connect = DriverManager.getConnection(url,user,password);     Statement stmt = connect.createStatement();     System.out.println("success to connect ");          /**      *      */       String lines = null;     String sql = "select * from StudentSystem";//要執行的SQL     String sql2 = "delete from StudentSystem where id =?";     String sql3 = "insert into StudentSystem(id,name,study,grade,birthplace)VALUES(?,?,?,?,?)";//SQL命令               PreparedStatement pst = (PreparedStatement)connect.prepareStatement(sql3);     pst = connect.prepareStatement(sql3);                 pst.setNString(1,str1);//1,2,3,為對應上面的參數，切記?。。。?！這里”12“傳給了第一個問號代表的 ID      pst.setString(2,str2);      pst.setString(3,str3);      pst.setString(4,str4);      pst.setString(5,str5);                     pst.executeUpdate();     JOptionPane.showMessageDialog(null, "該次錄入成功??！");          ResultSet rs = stmt.executeQuery(sql);     System.out.println("學號/t姓名/t專業/t年級/t出生");     while(rs.next()) {      System.out.print(rs.getString(1)+ "/t");      System.out.print(rs.getString(2)+ "/t");      System.out.print(rs.getString(3)+ "/t");      System.out.print(rs.getString(4)+ "/t");      System.out.print(rs.getString(5)+ "/t");      System.out.println();      if(lines != null){      lines = lines + "學號__姓名__專業__年級__出生/n" + rs.getString(1)+ "  "+ rs.getString(2)+ "  "+ rs.getString(3)        + " "+ rs.getString(4)+ "  "+ rs.getString(5)+ "   " + "/n/n";      } else {       lines ="數據庫中所有數據：/n/n" + "學號__姓名__專業__年級__出生/n" + rs.getString(1)+ ""+ rs.getString(2)+ " "+ rs.getString(3)         + "  "+ rs.getString(4)+ "   "+ rs.getString(5)+ " " + "/n";      }     }          JOptionPane.showMessageDialog(null, lines , "顯示",JOptionPane.INFORMATION_MESSAGE);    } catch (Exception e) {     e.printStackTrace();    }       }   /**    * ------------刪除功能------------    */   public static void delete_Student(String str){    try {     //添加JDBC驅動     Class.forName("com.mysql.jdbc.Driver");     String url = "jdbc:mysql://localhost/test";     String user = "root";     String password = "root";     //連接數據庫     Connection connect = DriverManager.getConnection(url,user,password);     Statement stmt = connect.createStatement();     System.out.println("success to connect ");            //**     String lines = null;     String sql = "select * from StudentSystem";//要執行的SQL     String sql2 = "delete from StudentSystem where id =?";     PreparedStatement pst = (PreparedStatement)connect.prepareStatement(sql2);     pst = connect.prepareStatement(sql2);     pst.setString(1,str);     pst.executeUpdate();          JOptionPane.showMessageDialog(null, "已刪除該條記錄", "刪除" ,JOptionPane.INFORMATION_MESSAGE);          ResultSet rs = stmt.executeQuery(sql);     System.out.println("學號/t姓名/t專業/t年級/t出生");     while(rs.next()) {      System.out.print(rs.getString(1)+ "/t");      System.out.print(rs.getString(2)+ "/t");      System.out.print(rs.getString(3)+ "/t");      System.out.print(rs.getString(4)+ "/t");      System.out.print(rs.getString(5)+ "/t");      System.out.println();      if(lines != null){      lines = lines + "學號__姓名__專業__年級__出生/n" + rs.getString(1)+ "  "+ rs.getString(2)+ "  "+ rs.getString(3)        + " "+ rs.getString(4)+ "  "+ rs.getString(5)+ "   " + "/n/n";      } else {       lines ="數據庫中所有數據：/n/n" + "學號__姓名__專業__年級__出生/n" + rs.getString(1)+ ""+ rs.getString(2)+ " "+ rs.getString(3)         + "  "+ rs.getString(4)+ "   "+ rs.getString(5)+ " " + "/n";      }     }          JOptionPane.showMessageDialog(null, lines , "顯示",JOptionPane.INFORMATION_MESSAGE);        } catch (Exception e) {     e.printStackTrace();    }       }  }