Java项目：员工管理系统（用数据库进行存储数据）
Employee（模板类）：
package com.employee.mysql;
import java.io.Serializable;
/**
* 员工类
*/
public class Employee implements Serializable {
private String name;// 姓名
private String age;// 年龄
private String sex;// 性别
private Integer id;// 工号
public Employee() {
}
public Employee(String name, String age, String sex, int id) {
this.setName(name);
this.setAge(age);
this.setSex(sex);
this.setId(id);
}
public Employee(String name, String age, String sex) {
this.setName(name);
this.setAge(age);
this.setSex(sex);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
@Override
public String toString() {
return "Employees [name=" + name + ", age=" + age + ", sex=" + sex + ", id=" + id + "]";
}
}SystemView（系统视图类）：
package com.employee.mysql;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import com.liuguangfa.employee.list.Employees;
public class SystemView {
Scanner scanner = new Scanner(System.in);
// 用于接收dao的实现类
EmployeeDAOimpl employeeDAOimpl = null;
// 通过构造函数去传递进来
public SystemView(EmployeeDAOimpl employeeDAOimpl) {
this.employeeDAOimpl = employeeDAOimpl;
}
public void start() {
System.out.println("欢迎来到员工管理系统");
String ai = "10";
do {
if (ai.equals("1")) {
addEmp();
ai = "10";
}
if (ai.equals("2")) {
deleteEmp();
ai = "10";
}
if (ai.equals("3")) {
modify();
ai = "10";
}
if (ai.equals("4")) {
query();
ai = "10";
}
if (ai.equals("5")) {
// exitApp();
break;
} else {
System.out.println("请输入你要进行的操作1.增加员工2.开除员工3.修改员工信息4.查询员工5.退出系统");
ai = scanner.next();
}
} while (true);
}
/**
* 添加员工
*/
public void addEmp() {
List<Employee> emps = new ArrayList<>();
boolean bool = false;
do {
System.out.println("请输入员工的姓名");
String name = scanner.next();
System.out.println("请输入员工的年龄");
String age = scanner.next();
System.out.println("请输入员工的性别");
String sex = scanner.next();
Employee emp = new Employee(name, age, sex);
emps.add(emp);
System.out.println("是否继续创建新的员工信息y/n");
String isYesAndNo = scanner.next();
if (isYesAndNo.toLowerCase().equals("y")) {
bool = true;
} else {
bool = false;
}
} while (bool);
employeeDAOimpl.addEmployee(emps);
}
/**
* 删除员工信息
*/
public void deleteEmp() {
boolean isDelete = false;
do {
System.out.println("请选择开除员工的方式1.按姓名2.按照id");
int count = scanner.nextInt();
if (count == 1) {
System.out.println("请输入你开除员工的姓名");
String name = scanner.next();
boolean bool = employeeDAOimpl.deleteEmployee(name);
if (bool) {
System.out.println("您开除员工成功");
} else {
System.out.println("你开除员工失败，请检查后重新输入");
}
} else if (count == 2) {
System.out.println("请输入你要开除员工的id");
int id = scanner.nextInt();
boolean bool = employeeDAOimpl.deleteEmployee(id);
if (bool) {
System.out.println("您开除员工成功");
} else {
System.out.println("你开除员工失败，请检查后重新输入");
}
}
System.out.println("是否继续开除的员工y/n");
String isYesAndNo = scanner.next();
if (isYesAndNo.toLowerCase().equals("y")) {
isDelete = true;
} else {
isDelete = false;
}
} while (isDelete);
}
/**
* 修改员工
*/
public void modify() {
boolean e = false;
do {
System.out.println("请输入你要修改员工的id");
int id = scanner.nextInt();
System.out.println("请选择你要修改的选项1.姓名2.年龄3.性别");
int isModify = scanner.nextInt();
if (isModify == 1) {
System.out.println("请输入你要修改成为什么名字？");
String name = scanner.next();
employeeDAOimpl.replaceByName(name, id);
System.out.println("您修改成功");
} else if (isModify == 2) {
System.out.println("请输入你要修改成为多少年龄？");
String age = scanner.next();
employeeDAOimpl.replaceByAge(age, id);
System.out.println("您修改成功");
} else if (isModify == 3) {
System.out.println("请输入你要修改成为什么性别？仅限男女");
String sex = scanner.next();
if (sex.equals("男")) {
employeeDAOimpl.replaceBysex(sex, id);
} else if (sex.equals("女")) {
employeeDAOimpl.replaceBysex(sex, id);
} else {
System.out.println("您输入错误请重新输入");
}
System.out.println("您修改成功");
}
System.out.println("是否继续修改的员工信息y/n");
String isYesAndNo = scanner.next();
if (isYesAndNo.toLowerCase().equals("y")) {
e = true;
} else {
e = false;
}
} while (e);
}
/**
* 查询员工信息
*/
public void query() {
boolean bool = false;
do {
System.out.println("请选择查询方式1.全部查询2.按照姓名查询3.按照id查询");
int count = scanner.nextInt();
List<Employee> emps = new ArrayList<>();
if (count == 1) {
emps = employeeDAOimpl.findAll();
for (int i = 0; i < emps.size(); i++) {
Employee emp = emps.get(i);
System.out.println("第" + (i + 1) + " 名员工是" + emp.toString());
}
} else if (count == 2) {
System.out.println("请输入你查询的姓名");
String name = scanner.next();
emps = employeeDAOimpl.findByName(name);
if (emps.size() == 0) {
System.out.println("您输入有误，请重新输入");
}
for (int i = 0; i < emps.size(); i++) {
Employee emp = emps.get(i);
System.out.println("第" + (i + 1) + " 名员工是" + emp.toString());
}
} else if (count == 3) {
System.out.println("请输入你查询的id，仅可输入数字序号");
Integer id = scanner.nextInt();
emps = employeeDAOimpl.finById(id);
if (emps.size() == 0) {
System.out.println("您输入有误，请重新输入");
}
for (int i = 0; i < emps.size(); i++) {
Employee emp = emps.get(i);
System.out.println("第" + (i + 1) + " 名员工是" + emp.toString());
}
} else {
System.out.println("您输入有误，请重新输入");
}
System.out.println("是否继续查询的员工信息y/n");
String isYesAndNo = scanner.next();
if (isYesAndNo.toLowerCase().equals("y")) {
bool = true;
} else {
bool = false;
}
} while (bool);
}
}Global（公共变量）：
package com.employee.mysql;
import java.sql.Connection;
/**
* 全局的变量或方法
*/
public class Global {
public static final String url =
"jdbc:mysql://localhost:3306/employee?charaterEncoding=UTF-8&useSSL=false&autoReconnect=true&serverTimeZone=Asia/Shanghai";
public static final String username = "root";
public static final String password = "123456";
/**
* 获取数据库连接
*
* @return
*/
public static Connection getConnection() {
return JdbcUtils.getConnection(url, username, password);
}
}Application（main方法类，系统入口）：
package com.employee.mysql;
public class Application {
public static void main(String[] args) {
//创建DAOimpl
EmployeeDAOimpl employeeDAOimpl = new EmployeeDAOimpl();
//创建员工视图
SystemView systemView = new SystemView(employeeDAOimpl);
//调用试图开始
systemView.start();
}
}JdbcUtils（数据库读取的工具类）：
package com.employee.mysql;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.lgf.shejimoshi.Logger;
public class JdbcUtils {
private final static String DRIVER = "com.mysql.cj.jdbc.Driver";
//创建日志管理器
private static Logger LOGGER = new SetLogger();
/**
* 查询
*/
public static <T> List<T> query(boolean antoClose, Connection conn, String sql, ResultSetHandler<List<T>> handler,
Object... args) {
try {
// 创建数据库载体
PreparedStatement ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
Object arg = args[i];
ps.setObject(i + 1, arg);
}
// 进行数据库查询，返回查询结果
ResultSet rs = ps.executeQuery();
return handler.handle(rs);
} catch (SQLException e) {
LOGGER.error("创建数据库载体失败");
//e.printStackTrace();
} finally {
if (antoClose) {
close(conn);
}
}
return null;
}
public <T> List<T> query(Connection conn, ResultSetHandler<List<T>> handler, String sql, Object... args) {
return query(false, conn, sql, handler, args);
}
/**
* 结果集转换成T 类型的接口
*
* @author liugu
*
*/
public static interface ResultSetHandler<T> {
public T handle(ResultSet rs);
}
/**
* 结果集转换器的实现类
*/
public static class ResuleSetHenderImpl<T> implements ResultSetHandler<List<T>> {
// 创建map集合，用于存放属性描述符、属性名称
private final Map<String, PropertyDescriptor> bdsMap = new HashMap<>();
// 创建构造函数，需要传进来一个class的值
private final Class<T> clazz;
public ResuleSetHenderImpl(Class<T> clazz) {
this.clazz = clazz;
try {
// 通过class获取类的元数据
BeanInfo bi = Introspector.getBeanInfo(clazz);
// 通过类的元数据获取属性描述符数组
PropertyDescriptor[] bds = bi.getPropertyDescriptors();
// 把属性描述符和属性名称存在map集合中
for (PropertyDescriptor bd : bds) {
bdsMap.put(bd.getName(), bd);
}
} catch (IntrospectionException e) {
// e.printStackTrace();
LOGGER.error("结果集转换失败");
}
}
@Override
public List<T> handle(ResultSet rs) {
List<T> results = new ArrayList<>();
try {
// 创建结果集列名存储的集合
List<String> fiels = new ArrayList<>();
// 获取结果集的元数据
ResultSetMetaData rsmd = rs.getMetaData();
// 迭代结果集元数据，并且把结果集元数据中的列名提取出来
int len = rsmd.getColumnCount();
for (int i = 0; i < len; i++) {
String fiel = rsmd.getColumnLabel(i + 1);
fiels.add(fiel);
}
while (rs.next()) {
// 通过class创建构造函数
Constructor<T> constructor = clazz.getDeclaredConstructor();
// 创建实例
T t = constructor.newInstance();
for (String fiel : fiels) {
// 从列名中找到相对想的fiel的属性
Object val = rs.getObject(fiel);
// 从map中取出属性描述符
PropertyDescriptor bd = bdsMap.get(underlineToCamel(fiel));
// 设置到目标方法上
Method method = bd.getWriteMethod();
// 通过反射给目标方法设置
method.invoke(t, convert(val, bd));
}
results.add(t);
}
} catch (Exception e) {
// e.printStackTrace();
LOGGER.error("创建数据库载体失败");
}
return results;
}
}
/**
* 把下划线命名转换成驼峰式命名
*/
private static String underlineToCamel(String str) {
String[] strs = str.split("_");
str = "";
for (int i = 0; i < strs.length; i++) {
String string = strs[i];
if (i >= 1) {
String head = strs[i].substring(0, 1);
String food = strs[i].substring(1, strs[i].length());
head = head.toUpperCase();
string = head + food;
}
str += string;
}
return str;
}
/**
* 根据属性描述符的类型，强制转换类型
*/
private static Object convert(Object val, PropertyDescriptor pd) {
// 返回成员属性的类型
Class<?> pdType = pd.getPropertyType();
if (pdType == Integer.class) {
return ((Number) val).intValue();
} else if (pdType == Long.class) {
return ((Number) val).longValue();
} else if (pdType == Float.class) {
return ((Number) val).floatValue();
} else if (pdType == Double.class) {
return ((Number) val).doubleValue();
}
return val;
}
/**
* 获取Connection
*/
public static Connection getConnection(String driver, String url, String username, String password) {
Connection conn = null;
try {
// 获取数据库驱动
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
} catch (Exception e) {
throw new RuntimeException("获取数据库失败");
}
return conn;
}
public static Connection getConnection(String url, String username, String password) {
return getConnection(DRIVER, url, username, password);
}
/**
* 关闭数据库链接
*/
public static void close(Connection conn) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
// e.printStackTrace();
LOGGER.error("关闭数据库载体失败");
}
}
}
/**
* 数据库的增删改
*/
public static int update(boolean antuClose, Connection conn, String sql, Object... args) {
PreparedStatement ps = null;
int len = 0;
try {
ps = conn.prepareStatement(sql);
for (int i = 0; i < args.length; i++) {
Object obj = args[i];
ps.setObject(i + 1, obj);
}
len = ps.executeUpdate();
} catch (SQLException e1) {
// e1.printStackTrace();
LOGGER.error("数据库更新失败");
} finally {
if (antuClose) {
close(conn);
}
}
return len;
}
public static int update(Connection conn, String sql, Object... args) {
return update(false, conn, sql, args);
}
}EmployeeDAO（DAO接口）：
package com.employee.mysql;
import java.util.List;
/**
* DAO：Data Access Object，数据存取对象
*
* @author liuguangfa
*
*/
public interface EmployeeDAO {
// /**
// * 数据库保存添加一个员工
// *
// * @return
// */
// boolean addEmployee(Employee employee);
/**
* 数据库冲保存多条员工信息
*/
int addEmployee(List<Employee> employeeList);
/**
* 删除员工（名字）
*/
boolean deleteEmployee(String name);
/**
* 删除员工（id）
*/
boolean deleteEmployee(int id);
/**
* 查询所有员工
*/
List<Employee> findAll();
/**
* 按照姓名查询
*/
List<Employee> findByName(String name);
/**
* 根据id 查询指定的员工
*/
List<Employee> finById(int id);
/**
* 修改员工姓名
*/
boolean replaceByName(String newName, int id);
/**
* 修改员工的年龄
*/
boolean replaceByAge(String newAge, int id);
/**
* 修改员工的性别
*/
boolean replaceBysex(String newSex, int id);
}EmployeeDAOimpl（DAO的实现类）：
package com.employee.mysql;
import java.sql.Connection;
import java.util.List;
import com.employee.mysql.JdbcUtils.ResuleSetHenderImpl;
public class EmployeeDAOimpl implements EmployeeDAO {
private final static ResuleSetHenderImpl<Employee> HANDLER = new ResuleSetHenderImpl<>(Employee.class);
// // 增加一个员工
// @Override
// public boolean addEmployee(Employee employee) {
// boolean bool = false;
// Connection conn = Global.getConnection();
// String sql = "insert into t_employee(id,name,sex,age) values (?,?,?,?)";
// int len = JdbcUtils.update(true, conn, sql, employee.getId(), employee.getName(), employee.getSex(),
// employee.getAge());
// if (len > 0) {
// bool = true;
// }
// return bool;
// }
// 往数据库中存多条数据(id自动生成，年龄、姓名、性别)
@Override
public int addEmployee(List<Employee> employees) {
Connection conn = Global.getConnection();
int count = 0;
for (Employee employee : employees) {
String sql = "insert into t_employee(name,sex,age) values (?,?,?)";
count = JdbcUtils.update( conn, sql, employee.getName(), employee.getSex(), employee.getAge());
}
JdbcUtils.close(conn);
return count;
}
// 删除员工（通过名字）
@Override
public boolean deleteEmployee(String name) {
boolean bool = false;
Connection conn = Global.getConnection();
String sql = "delete from t_employee where name = ?";
int len = JdbcUtils.update(true, conn, sql, name);
if (len > 0) {
bool = true;
}
return bool;
}
// 删除员工（通过id）
@Override
public boolean deleteEmployee(int id) {
boolean bool = false;
Connection conn = Global.getConnection();
String sql = "delete from t_employee where id = ?";
int len = JdbcUtils.update(true, conn, sql, id);
if (len > 0) {
bool = true;
}
return bool;
}
// 查询所有的员工信息
@Override
public List<Employee> findAll() {
Connection conn = Global.getConnection();
String sql = "select * from t_employee";
return JdbcUtils.query(true, conn, sql, HANDLER);
}
// 查询指定姓名的的员工
@Override
public List<Employee> findByName(String name) {
Connection conn = Global.getConnection();
String sql = "select * from t_employee where name = ?";
return JdbcUtils.query(true, conn, sql, HANDLER, name);
}
// 查询指定id的员工
@Override
public List<Employee> finById(int id) {
Connection conn = Global.getConnection();
String sql = "select * from t_employee where id = ?";
return JdbcUtils.query(true, conn, sql, HANDLER, id);
}
// 修改员工的姓名（通过id）
@Override
public boolean replaceByName(String newName, int id) {
boolean bool = false;
Connection conn = Global.getConnection();
String sql = "update t_employee set name = ? where id = ?";
int len = JdbcUtils.update(true, conn, sql, newName, id);
if (len > 0) {
bool = true;
}
return bool;
}
// 修改员工的年龄（通过id）
@Override
public boolean replaceByAge(String newAge, int id) {
boolean bool = false;
Connection conn = Global.getConnection();
String sql = "update t_employee set Age = ? where id = ?";
int len = JdbcUtils.update(true, conn, sql, newAge, id);
if (len > 0) {
bool = true;
}
return bool;
}
// 修改员工的性别（通过id）
@Override
public boolean replaceBysex(String newSex, int id) {
boolean bool = false;
Connection conn = Global.getConnection();
String sql = "update t_employee set sex = ? where id = ?";
int len = JdbcUtils.update(true, conn, sql, newSex, id);
if (len > 0) {
bool = true;
}
return bool;
}
}Logger（日志接口）：
package com.employee.mysql;
/**
* 日志管理器
*
* @author liuguangfa
*
*/
public interface Logger {
public void error(String message, Exception e);
public void error(String message);
}SetLogger（日志接口的实现类）：
package com.employee.mysql;
import com.lgf.shejimoshi.Logger;
/**
* 日志管理类实现类
*
* @author liuguangfa
*
*/
public class SetLogger implements Logger {
@Override
public void error(String message, Exception e) {
System.out.println(message + ":" + e);
}
@Override
public void error(String message) {
System.out.println(message);
}
}文章原文地址：刘广法，转载保留出处，感谢
