学生信息系统界面的实现 - JDBC
writer：pprp
登录界面的实现：
分为两个部分：
1、LoginFrame.java :
用windowbuilder进行快速搭建界面，构建好登录的界面，并用LogConnection类构建对象，进行处理，增加监听器。
2、LogConnection.java:
用基本的JDBC步骤进行处理，其中多加了一个判断用户名和密码匹配问题。
注意的问题：
1、只有在ResultSet对象使用完毕以后才能关掉Connection对象，否则会影响数据的传输，最后将连接关闭。
2、另外要注意在使用ResultSet进行结果查询的时候，需要加入一个判断，if(!rs.next())return ;否则会报错。
3、注意close函数应该在LogConnection中写，在LoginFrame的监听器中调用关闭。
LoginFrame.java
package work2;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
import work3.StudentFrame;
@SuppressWarnings("serial")
public class LoginFrame extends JFrame {
private JPanel contentPane;
private JTextField userFiled;
private JPasswordField pwd;
private LogConnection lc = null;
public static void main(String[] args) {
try {
UIManager
.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception e) {
e.printStackTrace();
}
LoginFrame frame = new LoginFrame();
frame.setVisible(true);
}
public LoginFrame() {
setTitle("学生信息管理系统");
lc = new LogConnection();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
JLabel lblNewLabel = new JLabel("u7528u6237u540DuFF1A");
lblNewLabel.setBounds(63, 68, 54, 15);
contentPane.add(lblNewLabel);
JLabel lblNewLabel_1 = new JLabel("u5BC6 u7801uFF1A");
lblNewLabel_1.setBounds(63, 128, 54, 15);
contentPane.add(lblNewLabel_1);
userFiled = new JTextField();
userFiled.setBounds(127, 65, 224, 23);
contentPane.add(userFiled);
// userFiled.setColumns(10);
pwd = new JPasswordField();
pwd.setBounds(127, 124, 224, 23);
contentPane.add(pwd);
JButton loginBtn = new JButton("u786Eu5B9A");
loginBtn.setBounds(63, 204, 93, 23);
contentPane.add(loginBtn);
JButton cancelBtn = new JButton("u53D6u6D88");
cancelBtn.setBounds(268, 204, 93, 23);
contentPane.add(cancelBtn);
loginBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
String name = userFiled.getText().trim();
String pwdText = String.valueOf(pwd.getPassword()).trim();
if (lc.Judge(name, pwdText)) {
JOptionPane.showMessageDialog(LoginFrame.this, "欢迎您，"
+ name);
@SuppressWarnings("unused")
StudentFrame tmp = new StudentFrame();
tmp.setVisible(true);
} else {
JOptionPane.showMessageDialog(LoginFrame.this, "用 户名或密码错误");
}
}
});
cancelBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
System.exit(0);
lc.close();
}
});
JOptionPane.showMessageDialog(LoginFrame.this, "欢迎登陆学生信息管理系统，请输入账号密码");
}
}
LogConnection.java
package work2;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class LogConnection {
Connection con = null;
Statement sql = null;
public LogConnection() {
// 1 drive
try {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("驱动加载成功");
} catch (ClassNotFoundException e) {
System.out.println("驱动加载失败");
e.printStackTrace();
}
// 2 connect
String url = "jdbc:mysql://localhost/test?useSSL=true";
String user = "root";
String password = "root";
try {
con = DriverManager.getConnection(url, user, password);
System.out.println("链接成功");
} catch (SQLException e) {
System.out.println("链接失败");
e.printStackTrace();
}
// 3 statement object
try {
sql = con.createStatement();
System.out.println("成功生成statement对象");
} catch (SQLException e) {
System.out.println("生成statement对象失败");
e.printStackTrace();
}
}
public boolean Judge(String name, String passwd) {
ResultSet rs = null;
String str = "select * from log where logname = '" + name + "'";
try {
rs = sql.executeQuery(str);
if (!rs.next())
return false;
} catch (SQLException e) {
e.printStackTrace();
return false;
}
try {
String cmpPwd = rs.getString(3);
if (cmpPwd.equals(passwd))
return true;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return false;
}
public void close(){
try {
con.close();
System.out.println("关闭成功");
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("关闭失败");
}
}
}
查询界面的实现：
要求：
设计学生信息管理系统。
使用Navicat的test数据库，创建Student表，包含学生的学号、姓名、年龄信息。根据以下的功能，编写相应的函数：
① 根据学号，可以查询到学生的姓名和年龄；
② 给定学生的学号、姓名、年龄，在表中追加一行信息；
③ 给定学生的学号，可以从表中删除该学生的信息；
使用图形界面实现任务三的学生信息管理系统设计。
分析：
用到上一个部分的登录界面，在登录界面的ActionListener中处理，如果成功登录，则打开查询、更新、删除界面进行操作。
Student.java: 其中是关于JDBC编程内容，为三个需求设计了三个函数，分别实现三个功能要求。
StudentFrame.java: 界面的设计，为四个按钮注册监听器，综合实现三种功能。
知识点：
1、用到的SQL语句比较多，要注意使用的时候需要在适当的时候加双引号，例如:
"insert into Student(sname,age)
values('"+name+"',"+age+")"
其中name和age都是变量。
2、注意数据库中编号是从1开始的，不是从0开始。
3、executeUpdate语句：是执行增删改的操作。
executeQuery语句：是执行查询操作的。
StudentFrame.java
package work3;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
import work2.LoginFrame;
@SuppressWarnings("serial")
public class StudentFrame extends JFrame {
private JPanel contentPane;
private JTextField searchStuNo;
private JTextField NameTextField;
private JTextField AgeTextField;
LoginFrame lf = null;
Student stu = null;
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch(Exception e){
e.printStackTrace();
}
StudentFrame frame = new StudentFrame();
frame.setVisible(true);
}
public StudentFrame() {
stu = new Student();
setTitle("学生信息查询系统");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
contentPane.setBackground(Color.PINK);
JLabel label = new JLabel("u67E5u8BE2u7684u5B66u53F7uFF1A");
label.setBounds(25, 29, 100, 27);
contentPane.add(label);
searchStuNo = new JTextField();
searchStuNo.setBounds(135, 32, 218, 24);
contentPane.add(searchStuNo);
searchStuNo.setColumns(10);
JButton SearchBtn = new JButton("u67E5u8BE2");
SearchBtn.setBounds(94, 66, 77, 23);
contentPane.add(SearchBtn);
JButton DeleteBtn = new JButton("u5220u9664");
DeleteBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
}
});
DeleteBtn.setBounds(276, 66, 77, 23);
contentPane.add(DeleteBtn);
JLabel label_1 = new JLabel(
"u52A0u5165u5B66u751Fu4FE1u606FuFF1A");
label_1.setBounds(25, 138, 100, 37);
contentPane.add(label_1);
NameTextField = new JTextField();
NameTextField.setBounds(177, 146, 58, 21);
contentPane.add(NameTextField);
NameTextField.setColumns(10);
AgeTextField = new JTextField();
AgeTextField.setBounds(286, 146, 58, 21);
contentPane.add(AgeTextField);
AgeTextField.setColumns(10);
JLabel label_2 = new JLabel("u59D3u540D:");
label_2.setBounds(135, 149, 36, 15);
contentPane.add(label_2);
JLabel label_3 = new JLabel("u5E74u9F84:");
label_3.setBounds(251, 149, 54, 15);
contentPane.add(label_3);
JButton SureBtn = new JButton("u786Eu5B9A");
SureBtn.setBounds(94, 203, 77, 23);
contentPane.add(SureBtn);
JButton ExitBtn = new JButton("u9000u51FA");
ExitBtn.setBounds(276, 203, 77, 23);
contentPane.add(ExitBtn);
SearchBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
int ssno = Integer.parseInt(searchStuNo.getText());
String tmp = stu.selectNameAge(ssno);
JOptionPane.showMessageDialog(StudentFrame.this, tmp);
searchStuNo.setText("");
}
});
DeleteBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
int ssno = Integer.parseInt(searchStuNo.getText());
if(stu.DeleteInf(ssno)){
JOptionPane.showMessageDialog(StudentFrame.this, "删除成功！");
}else {
JOptionPane.showMessageDialog(StudentFrame.this, "删除失败！");
}
searchStuNo.setText("");
}
});
ExitBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
System.exit(0);
}
});
SureBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
String ssname = NameTextField.getText();
int sage = Integer.parseInt(AgeTextField.getText());
stu.add(ssname,sage);
NameTextField.setText("");
AgeTextField.setText("");
JOptionPane.showMessageDialog(StudentFrame.this, "插入成功！");
}
});
}
}
Student.java
package work3;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Student {
Connection con = null;
Statement sql = null;
ResultSet rs = null;
public Student() {
// 1 drive
try {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("驱动加载成功");
} catch (ClassNotFoundException e) {
System.out.println("驱动加载失败");
e.printStackTrace();
}
// 2 connect
String url = "jdbc:mysql://localhost/test?useSSL=true";
String user = "root";
String password = "root";
try {
con = DriverManager.getConnection(url, user, password);
System.out.println("链接成功");
} catch (SQLException e) {
System.out.println("链接失败");
e.printStackTrace();
}
// 3 statement object
try {
sql = con.createStatement();
System.out.println("成功生成statement对象");
} catch (SQLException e) {
System.out.println("生成statement对象失败");
e.printStackTrace();
}
}
public String selectNameAge(int sno){
String sqls = "select sname,age from student where sno = '"+String.valueOf(sno)+"'";
try {
rs = sql.executeQuery(sqls);
if(!rs.next()){
return ("不存在！");
}
System.out.println("查询成功");
String stuname = rs.getString(1);
int stuage = rs.getInt(2);
return ("学号为"+sno+"的学生的姓名为:"+stuname+" ,年龄为:" + stuage);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("查询失败");
e.printStackTrace();
}
return "不存在";
}
public void add(String name,int age){
String str = "insert into Student(sname,age) values('"+name+"',"+age+")";
try {
sql.executeUpdate(str);
System.out.println("插入成功");
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("插入失败");
e.printStackTrace();
}
}
public boolean DeleteInf(int no){
String str = "delete from Student where sno = "+no+"";
try {
sql.executeUpdate(str);
System.out.println("删除成功");
return true;
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("删除失败");
e.printStackTrace();
}
return false;
}
}