㈠ 求一个简单又经典的java数据库连接的例子,要有源代码哦!
我就弄的用户登入的代码吧.这个挺简单的.
这是题目:
用户登陆验证：
1.创建数据库Test，并新建用户表users
字段包含：username varchar(20) not null
userpwd varchar(20) not null
在JBUILDER中编写Long类，实现登陆界面，并在用户输入用户名和密码后，
完成按纽的单击事件，对用户输入的数据进行验证，
（需要严整数据是否为空，密码长度必须是15位）,
并实现与数据库的连接，将用户输入的用户名密码与表中的记录比较，
若用户名正确且密码正确，弹出提示框告知登陆成功，否则登陆失败。
这是代码:
//连接数据库
boolean isLogin(String name,String pwd){
boolean flag=false;
Connection conn=null;
PreparedStatement pst=null;
ResultSet rs=null;
//加载驱动
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
//连接数据库
try {
conn=DriverManager.getConnection("jdbc:odbc:login");
String sql="select * from [user] where username=? and userpwd=?";
pst=conn.prepareStatement(sql);
pst.setString(1,name);
pst.setString(2,pwd);
rs=pst.executeQuery();
if(rs.next())
flag=true;
} catch (Exception ex) {
ex.printStackTrace();
}finally{
try {
conn.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
return flag;
}
//验证方法
public void jButton1_actionPerformed(ActionEvent e) {
String name=jTextField1.getText();
String pwd=jTextField2.getText();
//错误处理
if(name.equals("")||pwd.equals(""))
JOptionPane.showMessageDialog(this,"请输入完整的信息");
else {
if(isLogin(name,pwd))
JOptionPane.showMessageDialog(this,"登陆成功");
else
JOptionPane.showMessageDialog(this,"用户名或密码错误");
}
}
}
.....
.....
这是在事件里写的,
㈡ 用JAVA编程的通过SQL连接数据库的商品库存管理系统的源代码
导jar包,你给我邮箱我给你发一个jar包....
㈢ 求Java 注册登录 连接到数据库的源代码。
package cc.icoc.javaxu.;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class MySQLOprea { /** * 增加记录 INSERT INTO 表名(字段名，字段名) VALUES (值，值)； * 删除记录 DELETE FROM 表名 WHERE 条件() * 修改记录 UPDATE 表名 SET 字段=值，字段=值 WHERE 条件 * 查询记录 SELECT 字段，字段 FROM 表名 WHERE 条件 */ ResultSet rs = null; Connection conn = null; Statement statement = null; //链接 public Connection connSQL() { String DRIVER = "com.mysql.jdbc.Driver";// 数据库驱动 String URL = "jdbc:mysql://localhost:3306/mydata?useUnicode=true&characterEncoding=gb2312";// String DBNAME = "root";// 用户名 String DBPASS = "341341";// 密码 try { Class.forName(DRIVER).newInstance();// 注册驱动 conn = DriverManager.getConnection(URL, DBNAME, DBPASS); statement = conn.createStatement(); } catch (Exception e) {} return conn; } //增 /** * 插入新记录的操作 * @param table 表名 * @param userName 插入的用户名 * @param passWord 插入的用户密码 * @return true代表插入成功，false代表插入失败 */ public String insert(String table, String userName, String passWord) { connSQL(); String s = "注册成功"; try { String insert = "insert into "+table+"(userName,passWord) values ("+"'"+userName+"'"+","+"'"+passWord+"'"+")"; statement.executeUpdate(insert); closeDB(); } catch (Exception e) { // TODO: handle exception s = "注册失败"+e.toString(); } return s; } //删 public void delete(String table, String whereValue) throws SQLException { String delete = "Delete from "+table+" where userName = "+whereValue; statement.executeUpdate(delete); } //改 public void update(String table, String whereValue , String newValue) throws SQLException { String update = "Update "+table+" set passWord ="+newValue+" where userName ="+whereValue; statement.executeUpdate(update); } //查 public String query(String table , String whereValue1 ,String whereValue2, String whatCol1, String whatCol2) throws SQLException { connSQL(); String query = null;// ResultSet set= null; try { query = "select "+whatCol1+","+whatCol2+" from "+table +" where "+whatCol1+"="+'"'+whereValue1+'"'+" and "+whatCol2+"="+'"'+whereValue2+'"'; rs = statement.executeQuery(query); closeDB(); } catch (Exception e) { // TODO: handle exception return "false exception:"+e.toString(); } if(rs.next()) { return "true:"; } return "false:"; } private void closeDB() { // TODO Auto-generated method stub try { if(rs != null) { rs.close(); } if(statement != null) { statement.close(); } if(conn != null) { conn.close(); } } catch (Exception e) { // TODO: handle exception System.out.println("数据库关闭时出现异常"); } }}
㈣ 急求java学生信息管理系统源代码，带有连接数据库的，万分感谢
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.SwingConstants;
public class MainFrame extends JFrame implements ActionListener{
InsertPanel ip = null;
SelectPanel sp = null;
JPanel pframe;
JButton jb1,jb2,jb3;
JMenuItem jm11,jm21,jm22,jm23,jm31,jm32,jm41,jm42;
CardLayout clayout;
public MainFrame(String s){
super(s);
JMenuBar mb = new JMenuBar();
this.setJMenuBar(mb);
JMenu m1 = new JMenu("系统");
JMenu m2 = new JMenu("基本信息");
JMenu m3 = new JMenu("成绩");
JMenu m4 = new JMenu("奖惩");
mb.add(m1);
mb.add(m2);
mb.add(m3);
mb.add(m4);
jm11 = new JMenuItem("退出系统");
jm21 = new JMenuItem("输入");
jm22 = new JMenuItem("查询");
jm23 = new JMenuItem("更改");
jm31 = new JMenuItem("输入成绩");
jm32 = new JMenuItem("查询成绩");
jm41 = new JMenuItem("奖励");
jm42 = new JMenuItem("处分");
m1.add(jm11);
m2.add(jm21);
m2.add(jm22);
m2.add(jm23);
m3.add(jm31);
m3.add(jm32);
m4.add(jm41);
m4.add(jm42);
Icon i1 = new ImageIcon();
Icon i2 = new ImageIcon();
Icon i3 = new ImageIcon();
jb1 = new JButton(i1);
jb1.setToolTipText("输入");
jb2 = new JButton(i2);
jb2.setToolTipText("查询");
jb3 = new JButton(i3);
jb3.setToolTipText("退出");
JToolBar tb = new JToolBar("系统工具");
tb.add(jb1);
tb.add(jb2);
tb.add(jb3);
add(tb,BorderLayout.NORTH);
jm11.addActionListener(this);
jm21.addActionListener(this);
jm22.addActionListener(this);
jb1.addActionListener(this);
jb2.addActionListener(this);
jb3.addActionListener(this);
clayout = new CardLayout();
pframe = new JPanel(clayout);
add(pframe);
JPanel mainp = new JPanel(new BorderLayout());
JLabel mainl = new JLabel("学生信息管理平台",SwingConstants.CENTER);
mainl.setFont(new Font("serif",Font.BOLD,30));
mainp.add(mainl);
pframe.add(mainp,"main");
clayout.show(pframe, "main");
}
public void actionPerformed(ActionEvent e){
if(e.getSource() == jm21 || e.getSource() == jb1){
if(ip == null){
ip= new InsertPanel();
pframe.add(ip,"insert");
}
clayout.show(pframe, "insert");
this.setTitle("输入学生信息");
}
else if(e.getSource() == jm22 || e.getSource() == jb2){
if(sp == null){
sp= new SelectPanel();
pframe.add(sp,"select");
}
clayout.show(pframe, "select");
this.setTitle("查询学生信息");
}
else if(e.getSource() == jm11 || e.getSource() == jb3){
System.exit(0);
}
}
}
第二个：
import javax.swing.JFrame;
public class MainTest {
public static void main(String [] args){
MainFrame f = new MainFrame("学生信息管理平台");
f.setSize(400,300);
f.setLocation(350,250);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
第二个：
import java.sql.Connection;
import java.sql.DriverManager;
public class MySQLConnection {
static Connection getCon(){
Connection con = null;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost/test","root","123");
}
catch(Exception e){
System.out.println("建立数据库连接遇到异常！");
}
return con;
}
}
第四个：
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
public class SelectPanel extends JPanel implements ActionListener{
JButton jb;
JTextField jt;
JTextField jt1,jt2,jt3,jt4;
public SelectPanel(){
JLabel jl = new JLabel("请输入学号:",SwingConstants.CENTER);
jt = new JTextField();
jb = new JButton("确定");
JPanel jp1 = new JPanel(new GridLayout(1,3));
jp1.add(jl);
jp1.add(jt);
jp1.add(jb);
JLabel j1,j2,j3,j4;
j1 = new JLabel("学号:",SwingConstants.CENTER);
j2 = new JLabel("姓名:",SwingConstants.CENTER);
j3 = new JLabel("性别:",SwingConstants.CENTER);
j4 = new JLabel("年龄:",SwingConstants.CENTER);
jt1 = new JTextField(6);
jt1.setEditable(false);
jt2 = new JTextField(6);
jt2.setEditable(false);
jt3 = new JTextField(6);
jt3.setEditable(false);
jt4 = new JTextField(6);
jt4.setEditable(false);
JPanel jp2 = new JPanel(new BorderLayout());
JPanel jp3 = new JPanel(new GridLayout(4,2));
jp2.add(new JLabel(""),BorderLayout.NORTH);
jp3.add(j1);
jp3.add(jt1);
jp3.add(j2);
jp3.add(jt2);
jp3.add(j3);
jp3.add(jt3);
jp3.add(j4);
jp3.add(jt4);
jp2.add(jp3);
this.setLayout(new BorderLayout());
add(jp1,BorderLayout.NORTH);
add(jp2);
jb.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
if(e.getSource() == jb){
String stuNo = jt.getText().trim();
Student s = new Student();
boolean b = true;
try{
b = s.selectByStuNo(stuNo);
}
catch(Exception ex){
System.out.println("查询学生信息遇到异常!");
}
if(b){
jt1.setText(s.getStuNo());
jt2.setText(s.getName());
jt3.setText(s.getGender());
int a = s.getAge();
Integer i = new Integer(a);
jt4.setText(i.toString());
}
else{
JOptionPane.showMessageDialog(null, "无此学生!");
}
}
}
}
第五个：
import javax.swing.JFrame;
public class SelectTest {
public static void main(String [] args){
JFrame f = new JFrame("查询学生信息");
SelectPanel p = new SelectPanel();
f.add(p);
f.setSize(400,300);
f.setLocation(300,250);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
第六个：
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
public class Student {
String stuNo;
String name;
String gender;
int age;
public Student(){}
public Student(String stuNo,String name,String gender, int age){
this.stuNo = stuNo;
this.name = name;
this.gender = gender;
this.age = age;
}
public String getStuNo(){
return stuNo;
}
public void setStuNo(String stuNo){
this.stuNo = stuNo;
}
public String getName(){
return name;
}
public void setName(String name){
this.name = name;
}
public String getGender(){
return gender;
}
public void setGender(String gender){
this.gender = gender;
}
public int getAge(){
return age;
}
public void setAge(int age){
this.age = age;
}
public boolean insertStudent(){
boolean b = true;
try{
Connection con = MySQLConnection.getCon();
Statement statement = con.createStatement();
String sql = "insert into student values('" + stuNo + "','" + name +"','" + gender + "'," + age + ")";
sql = new String(sql.getBytes("gb2312"),"ISO8859_1");
statement.executeUpdate(sql);
con.close();
}
catch(Exception e){
b = false;
System.out.println("插入数据库遇到异常！");
}
return b;
}
public boolean selectByStuNo(String stuNo)throws Exception{
boolean b = true;
Connection con = MySQLConnection.getCon();
Statement statement = con.createStatement();
String sql = "select * from student where stuNo =" + stuNo;
ResultSet rs = statement.executeQuery(sql);
if(rs != null && rs.next()){
String no = rs.getString(1);
this.setStuNo(no);
String n = rs.getString(2);
n = new String(n.getBytes("ISO8859_1"),"gb2312");
this.setName(n);
String g = rs.getString(3);
g = new String (g.getBytes("ISO8859_1"),"gb2312");
this.setGender(g);
this.setAge(rs.getInt(4));
b = true;
}
rs.close();
statement.close();
con.close();
return b;
}
}
数据库你自己弄吧，我没时间弄了！初学得多动手哦