程序框架源于老师
学习笔记
1、java书写规范
右键文件Source -> Format 可自动调节
java的方法注释
2、Eclipse 中连接 mysql 数据库
新建 libs 文件，导入mysql-connector-java-8.0.23.jar（官网可免费下载），右键选择Build Path ->Add to Build Path，系统自动生成Referenced Libraries文件
在 module-info.java 中加上 require java.sql;
其中 cn.net.nit.ems 是包名
测试mysql是否连接成功
package cn.net.nit.ems;
import java.sql.*;
/**
* 测试数据库JDBC操作
* @author Administrator
*/
public class MySQLDemo {
public static void main(String[] args) throws Exception {
// 指定访问数据库的驱动程序的名称
String driver = "com.mysql.jdbc.Driver";
// 需要访问的数据库URL
String url = "jdbc:mysql://localhost:3306/course";
// 数据库访问的用户名
String db_user = "root";
// 数据库访问的密码
String db_pwd = "root";
// 要执行的查询SQL语句
String querySql = "SELECT * FROM UserInfo";
// 要执行的更新SQL语句
String updateSql = "UPDATE UserInfo SET Cell='88229530' WHERE ID=?";
// 声明一个Connection对象,用于和数据库建立连接
Connection conn = null;
// 声明一个Statement对象，用于对数据库执行SQL语句
Statement stmt = null;
// 预处理语句
PreparedStatement ps = null;
try {
// 装载驱动程序
Class.forName(driver);
// 获取和数据库的连接
conn = DriverManager.getConnection(url, db_user, db_pwd);
// 禁止自动递交，设置回滚点
conn.setAutoCommit(false);
// 创建一个Statement对象，用于对数据库执行SQL语句
stmt = conn.createStatement();
// 执行查询操作，得到的结果存放在ResultSet对象
ResultSet rs = stmt.executeQuery(querySql);
// 打印出查询到的所有数据
System.out.println("ID\tLoginName\tUserName\tUserPwd");
System.out.println("-------------------------------------------------");
while (rs.next()) {
int id = rs.getInt("ID");
String loginName = rs.getString("LoginName");
String userName = rs.getString("UserName");
String passWord = rs.getString("UserPwd");
System.out.println(id+"\t"+loginName+"\t\t"+userName+"\t\t"+passWord);
}
// 预编译SQL语句
ps = conn.prepareStatement(updateSql);
// 设置参数
ps.setInt(1,6);
// 更新数据库的记录，返回更新的记录数
int count = ps.executeUpdate();
System.out.println("更新记录："+count+"条");
// 事务递交
conn.commit();
} catch (Exception e) {
System.out.println("Error:"+e);
try { // 操作不成功则回滚
conn.rollback();
} catch (Exception ee) {}
} finally {
try {
if (conn!=null) conn.close();
if (stmt!=null) stmt.close();
} catch (SQLException e) {}
}
}
}
3、项目源代码
数据库名：course
用户表：UserInfo
角色表：RoleMember
总览
运行在 EMSApp.java 文件
DBHelper.java
package cn.net.nit.ems;
import java.sql.*;
public class DBHelper {
private static String driver = "com.mysql.cj.jdbc.Driver";
private static String url = "jdbc:mysql://localhost:3306/course";
private static String user = "root";
private static String pwd = "root";
public static Connection getConnection() {
Connection conn = null;
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, user, pwd);
conn.setAutoCommit(false);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
public static void close(Connection conn) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {}
conn = null;
}
}
public static void close(Statement stmt, ResultSet rs) {
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {}
}
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {}
}
}
}
EMSApp.java
package cn.net.nit.ems;
import java.util.Scanner;
import java.util.UUID;
/**
* 教学管理系统主类
*
* @author
*
*/
public class EMSApp {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("*******************************************");
System.out.println("*** ***");
System.out.println("*** 教务管理系统 v0.1 ***");
System.out.println("*** ***");
System.out.println("*******************************************");
String loginName, password;
System.out.println("[1] 登入");
System.out.println("[2] 注册");
int choice;
choice = scanner.nextInt();
System.out.println("用户名:");
loginName = scanner.next();
System.out.println("密码:");
password = scanner.next();
UserDAO dao = new UserDAO();
User user = dao.findUser(loginName, password);
if (choice == 2) {// 新用户注册账号，同时检测用户名是否重复
while (dao.isLoginNameDuplicate("LoginName", loginName)) {
System.out.println("该用户已存在！请重新输入！");
System.out.println("用户名:");
loginName = scanner.next();
System.out.println("密码:");
password = scanner.next();
}
User temUser = userInput(loginName, password);
if (dao.insert(temUser, temUser.getRole())) {
System.out.println("创建成功！请继续您的操作！");
user = temUser;
}
}
if (user != null && !user.getRole().equals("10")) { // 登录成功，学生没有操作权限
User studentUser;// 用来存放用于操作的学生用户信息
while (true) {
showMainMenu();
choice = scanner.nextInt();
switch (choice) {
// 增加学生信息
case 11:
System.out.println("增加学生信息");
System.out.println("提醒：生成的学生账户和密码默认为学号！");
User temUser = userInput(null, null);// 用于存放临时用户信息
while (temUser == null) {
System.out.println("该学号已存在！请重新输入！");
temUser = userInput(null, null);
}
if (dao.insert(temUser, temUser.getRole())) {
System.out.println("创建成功！请继续您的操作！\n");
studentUser = temUser;
}
break;
// 更改学生信息
case 12:
scanner.nextLine();// 消除一下回车
System.out.println("更改学生信息");
System.out.println("请输入要更改的学生学号：");
String temCode = scanner.nextLine();
while (dao.findUser(temCode) == null) {
System.out.println("学号错误！请重新输入更改学生学号：");
temCode = scanner.nextLine();
}
studentUser = dao.findUser(temCode);
while (true) {
showChangeStuMenu();
int options = scanner.nextInt();
String temChangedColumn = null, temChangedValue = null;
switch (options) {
case 1:
temChangedColumn = "LoginName";
break;
case 2:
temChangedColumn = "UserPwd";
break;
case 3:
temChangedColumn = "UserName";
break;
case 4:
temChangedColumn = "Sex";
break;
case 5:
temChangedColumn = "UserCode";
break;
case 6:
temChangedColumn = "DeptID";
break;
case 7:
temChangedColumn = "Cell";
break;
case 8:
temChangedColumn = "Email";
break;
}
if (options == 0) {
System.out.println("已返回菜单！");
break;
}
scanner.nextLine();// 消除一下回车
System.out.println("请输入新的值：");
temChangedValue = scanner.nextLine();
String temColumn = null;
if (options == 1) {
temColumn = "LoginName";
} else if (options == 5) {
temColumn = "UserCode";
}
while (dao.isLoginNameDuplicate(temColumn, temChangedValue)) {
System.out.println("该账号或学号已存在！请重新输入！");
System.out.println("请输入新的值：");
temChangedValue = scanner.nextLine();
}
if (dao.changeStuents(studentUser, temChangedColumn, temChangedValue)) {
System.out.println("修改成功！请继续您的操作！\n");
studentUser = dao.findUser(temCode);
}
}
break;
// 删除学生信息
case 13:
scanner.nextLine();// 消除一下回车
System.out.println("删除学生信息");
System.out.println("请输入要删除的学生学号：");
temCode = scanner.nextLine();
while (dao.findUser(temCode) == null) {
System.out.println("学号错误！请重新输入要删除的学生学号：");
temCode = scanner.nextLine();
}
studentUser = dao.findUser(temCode);
if (dao.deleteStuents(studentUser)) {
System.out.println("删除成功！请继续您的操作！\n");
}
break;
// 列出学生信息
case 14:
System.out.println("列出学生信息");
if (dao.showStuents()) {
System.out.println("展示成功！请继续您的操作！\n");
}
break;
// 离开系统
case 0:
System.out.println("Bye!");
break;
}
System.out.println("\n");
if (choice == 0)
break;
}
} else if (user.getRole().equals("10")) {
System.out.println("抱歉，学生无权限操作！");
} else {
Util.Log("用户名或密码有误!");
}
// Do some cleaning work
if (choice == 0) {
scanner.close();
}
}
/**
* 显示主界面菜单
*/
private static void showMainMenu() {
System.out.println("[1] 学籍管理");
System.out.println(" [11] 增加学生信息");
System.out.println(" [12] 更改学生信息");
System.out.println(" [13] 删除学生信息");
System.out.println(" [14] 列出学生信息");
System.out.println("[2] 成绩管理");
System.out.println(" [21] 增加课程信息");
System.out.println(" [22] 更改课程信息");
System.out.println(" [23] 删除课程信息");
System.out.println(" [24] 列出课程信息");
// System.out.println(" [25] 输入学生成绩");
System.out.println("[0] 退出系统");
}
private static User userInput(String loginName, String password) {
String temName, temCode, temSex, temDept, temCell, temRole, temEmail;// 临时储存变量
Scanner scanner = new Scanner(System.in);
UserDAO dao = new UserDAO();
User temUser = new User(loginName, password);
// ---------学号或工号，账号和密码----------------------------//
System.out.println("请输入学号或工号：");
temCode = scanner.next();
while (dao.isLoginNameDuplicate("UserCode", temCode)) {
System.out.println("该学号已存在！请重新输入！");
System.out.println("请输入学号或工号：");
temCode = scanner.next();
}
temUser.setUserCode(temCode);
if (loginName == null) {
temUser = new User(temCode, temCode);// 如果账号密码无效就自动用“学号或工号”代替
temUser.setUserCode(temCode);
}
// ---------姓名----------------------------//
System.out.println("请输入姓名：");
temName = scanner.next();
temUser.setUserName(temName);
// ---------性别----------------------------//
System.out.println("请输入性别：（男为0，女为1）");
temSex = scanner.next();
while (!temSex.equals("0") && !temSex.equals("1")) {
System.out.println("输入不合法！请重新输入！");
System.out.println("请输入性别：（男为0，女为1）");
temSex = scanner.next();
}
temUser.setSex(temSex);
// ---------班级或部门编号----------------------------//
System.out.println("请输入班级或部门编号：");
temDept = scanner.next();
temUser.setDeptId(temDept);
// ---------手机号码----------------------------//
System.out.println("请输入手机号码：");
temCell = scanner.next();
temUser.setCell(temCell);
// ---------电子邮箱----------------------------//
System.out.println("请输入电子邮箱：");
temEmail = scanner.next();
temUser.setEmail(temEmail);
// ---------职位角色----------------------------//
System.out.println("请输入职位角色（学生为10，教师为20，管理员为30）：");
temRole = scanner.next();
while (!temRole.equals("10") && !temRole.equals("20") && !temRole.equals("30")) {
System.out.println("输入不合法！请重新输入！");
System.out.println("请输入职位（学生为10，教师为20，管理员为30）：");
temRole = scanner.next();
}
temUser.setRole(temRole);
// ---------用户ID----------------------------//
UUID uuid = UUID.randomUUID();
temUser.setUserId(uuid.toString());// 分配唯一用户ID
return temUser;
}
private static void showChangeStuMenu() {
System.out.println("[1] 用户名");
System.out.println("[2] 密码");
System.out.println("[3] 姓名");
System.out.println("[4] 性别");
System.out.println("[5] 学号");
System.out.println("[6] 班级");
System.out.println("[7] 电话");
System.out.println("[8] 电子邮箱");
System.out.println("[0] 退出系统");
}
}
MySQLDemo.java
用于测试 mysql 是否连接成功
package cn.net.nit.ems;
import java.sql.*;
/**
* 测试数据库JDBC操作
* @author Administrator
*/
public class MySQLDemo {
public static void main(String[] args) throws Exception {
// 指定访问数据库的驱动程序的名称
String driver = "com.mysql.jdbc.Driver";
// 需要访问的数据库URL
String url = "jdbc:mysql://localhost:3306/course";
// 数据库访问的用户名
String db_user = "root";
// 数据库访问的密码
String db_pwd = "root";
// 要执行的查询SQL语句
String querySql = "SELECT * FROM UserInfo";
// 要执行的更新SQL语句
String updateSql = "UPDATE UserInfo SET Cell='88229530' WHERE ID=?";
// 声明一个Connection对象,用于和数据库建立连接
Connection conn = null;
// 声明一个Statement对象，用于对数据库执行SQL语句
Statement stmt = null;
// 预处理语句
PreparedStatement ps = null;
try {
// 装载驱动程序
Class.forName(driver);
// 获取和数据库的连接
conn = DriverManager.getConnection(url, db_user, db_pwd);
// 禁止自动递交，设置回滚点
conn.setAutoCommit(false);
// 创建一个Statement对象，用于对数据库执行SQL语句
stmt = conn.createStatement();
// 执行查询操作，得到的结果存放在ResultSet对象
ResultSet rs = stmt.executeQuery(querySql);
// 打印出查询到的所有数据
System.out.println("ID\tLoginName\tUserName\tUserPwd");
System.out.println("-------------------------------------------------");
while (rs.next()) {
int id = rs.getInt("ID");
String loginName = rs.getString("LoginName");
String userName = rs.getString("UserName");
String passWord = rs.getString("UserPwd");
System.out.println(id+"\t"+loginName+"\t\t"+userName+"\t\t"+passWord);
}
// 预编译SQL语句
ps = conn.prepareStatement(updateSql);
// 设置参数
ps.setInt(1,6);
// 更新数据库的记录，返回更新的记录数
int count = ps.executeUpdate();
System.out.println("更新记录："+count+"条");
// 事务递交
conn.commit();
} catch (Exception e) {
System.out.println("Error:"+e);
try { // 操作不成功则回滚
conn.rollback();
} catch (Exception ee) {}
} finally {
try {
if (conn!=null) conn.close();
if (stmt!=null) stmt.close();
} catch (SQLException e) {}
}
}
}
User.java
package cn.net.nit.ems;
public class User {
/** 用户ID */
private String userId;
/** 登录帐户名 */
private String loginName;
/** 真实姓名 */
private String userName;
/** 学号或工号 */
private String userCode;
/** 性别：'0'-男；'1'-女 */
private String sex;
private String password;
/** 班级或部门编号 */
private String deptId;
/** 手机号码 */
private String cell;
private String email;
/** 角色："admin"-管理员;"user"-普通用户 */
private String role;
public User(String loginName, String password) {
this.loginName = loginName;
this.password = password;
}
public User() {
}
public String toString() {
return userName + "\t" + userCode + "\t" + sex + "\t" + deptId + "\t" + loginName + "\t" + password + "\t"
+ cell + "\t" + email + "\t" + role + "\t" + userId;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getLoginName() {
return loginName;
}
public void setLoginName(String loginName) {
this.loginName = loginName;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserCode() {
return userCode;
}
public void setUserCode(String userCode) {
this.userCode = userCode;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getDeptId() {
return deptId;
}
public void setDeptId(String deptId) {
this.deptId = deptId;
}
public String getCell() {
return cell;
}
public void setCell(String cell) {
this.cell = cell;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
}
UserDAO.java
package cn.net.nit.ems;
import java.sql.*;
import java.util.UUID;
public class UserDAO {
private String db_driver = "com.mysql.cj.jdbc.Driver";
private String db_url = "jdbc:mysql://localhost:3306/course";
private String db_user = "root";
private String db_pwd = "root";
/**
* 查询用户（通过账号密码查找）
*
* @param userId 用户ID
* @param password 密码
*/
public User findUser(String loginName, String password) {
Connection conn = null;
try {
conn = DBHelper.getConnection();
if (conn == null)
throw new SQLException("UserDAO: 无法获得数据库连接!");
String sql = "SELECT * FROM UserInfo WHERE LoginName = '" + loginName + "'";
if (password != null) {
sql += " AND UserPwd='" + password + "'";
}
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(sql);
User user = new User();
if (rs.next()) {
user.setUserId(rs.getString("UserID"));
user.setUserName(rs.getString("UserName"));
user.setLoginName(rs.getString("LoginName"));
user.setSex(rs.getString("Sex"));
user.setCell(rs.getString("Cell"));
user.setEmail(rs.getString("Email"));
user.setDeptId(rs.getString("DeptID"));
}
sql = "SELECT * FROM RoleMember WHERE UserID = '" + user.getUserId() + "'";
rs = st.executeQuery(sql);
if (rs.next()) {
user.setRole(rs.getString("RoleID"));
return user;
}
} catch (Exception ex) {
System.out.println("UserDAO SQLException: " + ex);
} finally {
DBHelper.close(conn);
}
return null;
}
/**
* 查询用户（通过学号查找）
*
* @param userCode 学生学号
*/
public User findUser(String userCode) {
Connection conn = null;
try {
conn = DBHelper.getConnection();
if (conn == null)
throw new SQLException("UserDAO: 无法获得数据库连接!");
String sql = "SELECT * FROM UserInfo WHERE UserCode = '" + userCode + "'";
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(sql);
if (rs.next()) {
User user = new User();
user.setUserCode(rs.getString("UserCode"));
user.setLoginName(rs.getString("LoginName"));
user.setPassword(rs.getString("UserPwd"));
user.setUserId(rs.getString("UserID"));
user.setUserName(rs.getString("UserName"));
user.setLoginName(rs.getString("LoginName"));
user.setSex(rs.getString("Sex"));
user.setCell(rs.getString("Cell"));
user.setEmail(rs.getString("Email"));
user.setDeptId(rs.getString("DeptID"));
return user;
}
} catch (Exception ex) {
System.out.println("UserDAO SQLException: " + ex);
} finally {
DBHelper.close(conn);
}
return null;
}
/**
* 新增用户
*
* @param user 用户对象
* @param role 用户角色："10"-学生；"20"-教师；"30"-管理员
* @return true 新增用户成功
*/
public boolean insert(User user, String role) {
String sql = " INSERT INTO UserInfo(UserID,LoginName, UserName, UserPwd, UserCode, Sex, DeptID, Cell, Email) VALUES (?,?, ?, ?, ?, ?, ?, ?, ?)";
Connection conn = null;
try {
Class.forName(db_driver);
conn = DriverManager.getConnection(db_url, db_user, db_pwd);
if (conn == null)
throw new Exception("UserDAO: 无法获得数据库连接!");
conn.setAutoCommit(false);
PreparedStatement ps = null;
int num = 1;
ps = conn.prepareStatement(sql);
ps.setString(num++, user.getUserId());
ps.setString(num++, user.getLoginName());
ps.setString(num++, user.getUserName());
ps.setString(num++, user.getPassword());
ps.setString(num++, user.getUserCode());
ps.setString(num++, user.getSex());
ps.setString(num++, user.getDeptId());
ps.setString(num++, user.getCell());
ps.setString(num++, user.getEmail());
if (ps.executeUpdate() <= 0) {
throw new Exception("插入表UserInfo出错！");
}
// 插入角色成员表
sql = "INSERT INTO RoleMember(UserID, RoleID) VALUES(?, ?)";
ps = conn.prepareStatement(sql);
ps.setString(1, user.getUserId());
ps.setString(2, role);
if (ps.executeUpdate() <= 0) {
throw new Exception("插入表RoleMember出错！");
}
conn.commit();
return true;
} catch (Exception e) {
System.err.println("****插入表UserInfo出错！");
e.printStackTrace();
try {
if (conn != null)
conn.rollback();
} catch (Exception ex) {
}
return false;
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
}
}
}
}
/**
* 检测用户登入账号或者学号是否重复
*
* @param column 要检测的数据列名
* @param loginNameOrUserCode 用户登入账号或者学号
* @return true 用户重复
*/
public boolean isLoginNameDuplicate(String column, String loginNameOrUserCode) {
String sql = "SELECT * FROM UserInfo WHERE " + column + " = '" + loginNameOrUserCode + "'";
Connection conn = null;
try {
Class.forName(db_driver);
conn = DriverManager.getConnection(db_url, db_user, db_pwd);
if (conn == null)
throw new Exception("UserDAO: 无法获得数据库连接!");
conn.setAutoCommit(false);
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(sql);
if (rs.next()) {
return true;
}
return false;
} catch (Exception e) {
System.err.println("****检测用户是否重复出错！");
e.printStackTrace();
try {
if (conn != null)
conn.rollback();
} catch (Exception ex) {
}
return false;
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
}
}
}
}
/**
* 修改学生信息
*
* @param user 用户对象
* @param changedColumn 需要修改的列名
* @param changedValue 新的数值
*/
public boolean changeStuents(User user, String changedColumn, String changedValue) {
String sql = "UPDATE UserInfo SET " + changedColumn + " = ? WHERE UserCode = ?";
Connection conn = null;
try {
Class.forName(db_driver);
conn = DriverManager.getConnection(db_url, db_user, db_pwd);
if (conn == null)
throw new Exception("UserDAO: 无法获得数据库连接!");
conn.setAutoCommit(false);
PreparedStatement ps = null;
ps = conn.prepareStatement(sql);
ps.setString(1, changedValue);
ps.setString(2, user.getUserCode());
if (ps.executeUpdate() <= 0) {
throw new Exception("修改表UserInfo出错！");
}
conn.commit();
return true;
} catch (Exception e) {
System.err.println("****修改表UserInfo出错！");
e.printStackTrace();
try {
if (conn != null)
conn.rollback();
} catch (Exception ex) {
}
return false;
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
}
}
}
}
/**
* 删除学生信息
*
* @param user 被删除用户对象
*/
public boolean deleteStuents(User user) {
String sql = "DELETE FROM UserInfo WHERE UserCode = ?";
Connection conn = null;
try {
Class.forName(db_driver);
conn = DriverManager.getConnection(db_url, db_user, db_pwd);
if (conn == null)
throw new Exception("UserDAO: 无法获得数据库连接!");
conn.setAutoCommit(false);
PreparedStatement ps = null;
ps = conn.prepareStatement(sql);
ps.setString(1, user.getUserCode());
if (ps.executeUpdate() <= 0) {
throw new Exception("删除表UserInfo数据出错！");
}
conn.commit();
return true;
} catch (Exception e) {
System.err.println("****删除表UserInfo数据出错！");
e.printStackTrace();
try {
if (conn != null)
conn.rollback();
} catch (Exception ex) {
}
return false;
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
}
}
}
}
/**
* 展示学生信息
*/
public boolean showStuents() {
String sql = "SELECT * FROM UserInfo";
Connection conn = null;
try {
Class.forName(db_driver);
conn = DriverManager.getConnection(db_url, db_user, db_pwd);
if (conn == null)
throw new Exception("UserDAO: 无法获得数据库连接!");
conn.setAutoCommit(false);
System.out.println("姓名\t学号\t性别\t班级\t用户名\t密码\t电话\t电子邮件\t\t角色用户ID");
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(sql);
while (rs.next()) {
User user = new User();
user.setUserCode(rs.getString("UserCode"));
user.setLoginName(rs.getString("LoginName"));
user.setPassword(rs.getString("UserPwd"));
user.setUserId(rs.getString("UserID"));
user.setUserName(rs.getString("UserName"));
user.setSex(rs.getString("Sex"));
user.setCell(rs.getString("Cell"));
user.setEmail(rs.getString("Email"));
user.setDeptId(rs.getString("DeptID"));
String sql1 = "SELECT * FROM RoleMember WHERE UserID ='" + user.getUserId() + "'";
Statement st1 = conn.createStatement();
ResultSet rs1 = st1.executeQuery(sql1);
if (rs1.next())
user.setRole(rs1.getString("RoleID"));
System.out.println(user.toString());
}
return true;
} catch (Exception e) {
System.err.println("****显示表UserInfo数据出错！");
e.printStackTrace();
try {
if (conn != null)
conn.rollback();
} catch (Exception ex) {
}
return false;
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
}
}
}
}
}
Util.java
package cn.net.nit.ems;
public class Util {
/**
* 输出日志信息
* @param log
*/
public static void Log(String log)
{
System.out.println(log);
}
}
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