基于JDBC和Druid的CMS客户管理系统实操案例
1. 客户表
CREATE TABLE t_customer(
id INT PRIMARY KEY AUTO_INCREMENT COMMENT '客户主键',
name VARCHAR(20) COMMENT '客户名称',
gender VARCHAR(4) COMMENT '客户性别',
age INT COMMENT '客户年龄',
salary DOUBLE(8,1) COMMENT '客户工资',
phone VARCHAR(11) COMMENT '客户电话')
2. 项目结构
2.1 JavaBean
Customer.java
package com.atguigu.cms.javabean;
public class Customer {
private int id;
private String name;// : 姓名
private String gender; // 性别
private int age;// : 年龄
private double salary;// : 工资
private String phone; // 电话
public Customer() {}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
@Override
public String toString() {
return id + "\t" + name + (name.length() < 3 ? "\t\t" : "\t") + gender + "\t\t" + age + "\t\t" + salary + "\t\t" + phone;
}
}
2.2 封装的JDBCUTILS
JdbcUtil.java
package com.atguigu.cms.utils;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
/**
* @Title: JdbcUtil
* @Package: com.atguigu.cms.utils
* @Description: 将JDBC标准操作步骤中的注册驱动、获取连接、释放连接功能进行封装
* @Author: untifa
* @Date: 2023/3/26 - 12:07
*/
public class JdbcUtil {
private static DataSource dataSource = null;
private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();
static {
Properties properties = new Properties();
InputStream resourceAsStream = JdbcUtil.class.getClassLoader().getResourceAsStream("druid.properties");
try {
properties.load(resourceAsStream);
} catch (IOException e) {
throw new RuntimeException(e);
}
try {
dataSource = DruidDataSourceFactory.createDataSource(properties);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public static Connection getConnection() throws SQLException {
if (tl.get() == null) {
Connection connection = dataSource.getConnection();
tl.set(connection);
}
return tl.get();
}
public static void freeConnection() throws SQLException {
Connection connection = tl.get();
if (connection != null) {
tl.remove();
}
connection.setAutoCommit(true);
connection.close();
}
}
BaseDao.java
package com.atguigu.cms.utils;
import java.lang.reflect.Field;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
/**
* @Title: BaseDao
* @Package: com.atguigu.cms.utils
* @Description: 将JDBC标准操作步骤中的执行DQL并获取返回信息、执行非DQL并获取返回信息功能进行封装
* @Author: untifa
* @Date: 2023/3/26 - 12:08
*/
public class BaseDao {
public int update(String sql, Object... params) throws SQLException {
Connection connection = JdbcUtil.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
preparedStatement.setObject(i + 1, params[i]);
}
int rows = preparedStatement.executeUpdate();
preparedStatement.close();
if (connection.getAutoCommit()) {
JdbcUtil.freeConnection();
}
return rows;
}
public <T> List<T> query(Class<T> clazz, String sql, Object... params) throws Exception {
Connection connection = JdbcUtil.getConnection();
PreparedStatement preparedStatement = connection.prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
preparedStatement.setObject(i + 1, params[i]);
}
ResultSet resultSet = preparedStatement.executeQuery();
ResultSetMetaData metaData = preparedStatement.getMetaData();
int columnCount = metaData.getColumnCount();
ArrayList<T> list = new ArrayList<T>();
while (resultSet.next()) {
T t = clazz.newInstance();
for (int i = 0; i < columnCount; i++) {
Field declaredField = clazz.getDeclaredField(metaData.getColumnLabel(i+1));
declaredField.setAccessible(true);
declaredField.set(t, resultSet.getObject(i+1));
}
list.add(t);
}
resultSet.close();
preparedStatement.close();
if (connection.getAutoCommit()) {
JdbcUtil.freeConnection();
}
return list;
}
}
2.3 Main程序入口
CustomerManage.java
package com.atguigu.cms.main;
import com.atguigu.cms.view.CustomerView;
public class CustomerManage {
public static void main(String[] args) {
CustomerView view = new CustomerView();
view.enterMainMenu();
}
}
2.4 UI程序入口
CustomerView.java
package com.atguigu.cms.view;
import com.atguigu.cms.javabean.Customer;
import com.atguigu.cms.service.CustomerService;
import java.util.List;
/**
* 这是主控模块, 负责菜单显示和用户交互. 也称为UI, 内部要频繁到管理器对象, 所以使用对象关联
*/
public class CustomerView {
/**
* 关联到的管理器对象
*/
private CustomerService customerService = new CustomerService();
/**
* 进入主菜单, 是项目的真正入口, 不可以轻易结束
*/
public void enterMainMenu() {
// 1) 声明布尔
boolean loopFlag = true;
// 2) 写循环
do {
System.out.println("\n--------------------------------客户信息管理--------------------------------------\n");
listAllCustomers();
System.out.print("1 添加客户 2 修改客户 3 删除客户 4 客户列表 5 退 出 请选择(1 - 5) : ");
// 读取用户选择
char choice = KeyboardUtility.readMenuSelection();
switch (choice) {
case '1' : addNewCustomer(); break;
case '2' : modifyCustomer(); break;
case '3' : deleteCustomer(); break;
case '4' : listAllCustomers(); break;
case '5' :
System.out.print("确认是否退出(Y/N) : ");
// 获取用户输入的确认
char confirm = KeyboardUtility.readConfirmSelection();
if (confirm == 'Y') {
loopFlag = false;
}
break;
}
} while (loopFlag);
}
/**
* 添加新员工
*/
private void addNewCustomer() {
Customer customer = new Customer();
System.out.println("---------------------添加客户---------------------");
System.out.print("姓名 : ");
String name = KeyboardUtility.readString(10);
customer.setName(name);
System.out.print("性别 : ");
String gender = KeyboardUtility.readString(1);
customer.setGender(gender);
System.out.print("年龄 : ");
int age = KeyboardUtility.readInt();
customer.setAge(age);
System.out.print("工资 : ");
int salary = KeyboardUtility.readInt();
customer.setSalary(salary);
System.out.print("电话 : ");
String phone = KeyboardUtility.readString(15);
customer.setPhone(phone);
// 通过调用管理器对象完成 员工添加
customerService.addCustomer(customer);
System.out.println("---------------------添加完成---------------------");
}
/**
* 修改员工
*/
private void modifyCustomer () {
System.out.println("---------------------修改客户---------------------");
System.out.print("请选择待修改客户ID(-1退出) : ");
// 获取用户输入的id
int id = KeyboardUtility.readInt();
if (id == -1) {
return;
}
// 根据编号定位要修改的目标对象
Customer target = customerService.getCustomer(id);
if (target == null) {
System.out.println("--------------指定ID[" + id + "]的客户不存在-----------------");
return;
}
System.out.println("<直接回车表示不修改>");
System.out.print("姓名(" + target.getName() + ") : ");
String name = KeyboardUtility.readString(10, target.getName());
target.setName(name);
System.out.print("年龄(" + target.getAge() + ") : ");
int age = KeyboardUtility.readInt(target.getAge());
target.setAge(age);
System.out.print("工资(" + target.getSalary() + ") : ");
int salary = KeyboardUtility.readInt((int) target.getSalary());
target.setSalary(salary);
System.out.print("电话(" + target.getPhone() + ") : ");
String phone = KeyboardUtility.readString(15, target.getPhone());
target.setPhone(phone);
customerService.modifyCustomer(id, target);
System.out.println("---------------------修改完成---------------------");
}
/**
* 删除员工
*/
private void deleteCustomer () {
System.out.println("---------------------删除客户---------------------");
System.out.print("请选择待删除客户ID(-1退出) : ");
// 获取用户输入的ID
int id = KeyboardUtility.readInt();
if (id == -1) {
return;
}
System.out.print("确认是否删除(Y/N) : ");
// 获取用户输入的确认
char confirm = KeyboardUtility.readConfirmSelection();
if (confirm == 'Y') {
boolean flag = customerService.removeCustomer(id);
if (flag) {
System.out.println("---------------------删除完成---------------------");
} else {
System.out.println("--------------指定ID[" + id + "]的客户不存在-----------------");
}
}
}
/**
* 员工列表
*/
private void listAllCustomers() {
System.out.println("---------------------------------客户列表--------------------------------------");
// 真的获取所有员工
List<Customer> list = customerService.getList();
if (list == null || list.size() == 0) {
System.out.println("没有数据, 请添加新数据...");
} else {
System.out.println("ID\t姓名\t\t性别\t\t年龄\t\t工资\t\t\t电话");
for (Customer customer : list) {
System.out.println(customer);
}
}
System.out.println("-----------------------------------------------------------------------------");
}
}
KeyboardUtility.java
package com.atguigu.cms.view;
import java.util.Scanner;
public class KeyboardUtility {
private static Scanner scanner = new Scanner(System.in);
public static void readReturn() {
System.out.print("按回车键继续...");
readKeyBoard(100, true);
}
public static char readMenuSelection() {
char c;
for (; ; ) {
String str = readKeyBoard(1, false);
c = str.charAt(0);
if (c != '1' && c != '2' &&
c != '3' && c != '4' && c != '5') {
System.out.print("选择错误，请重新输入：");
} else break;
}
return c;
}
public static char readChar() {
String str = readKeyBoard(1, false);
return str.charAt(0);
}
public static char readChar(char defaultValue) {
String str = readKeyBoard(1, true);
return (str.length() == 0) ? defaultValue : str.charAt(0);
}
public static int readInt() {
int n;
for (; ; ) {
String str = readKeyBoard(8, false);
try {
n = Integer.parseInt(str);
break;
} catch (NumberFormatException e) {
System.out.print("数字输入错误，请重新输入：");
}
}
return n;
}
public static int readInt(int defaultValue) {
int n;
for (; ; ) {
String str = readKeyBoard(8, true);
if (str.equals("")) {
return defaultValue;
}
try {
n = Integer.parseInt(str);
break;
} catch (NumberFormatException e) {
System.out.print("数字输入错误，请重新输入：");
}
}
return n;
}
public static String readString(int limit) {
return readKeyBoard(limit, false);
}
public static String readString(int limit, String defaultValue) {
String str = readKeyBoard(limit, true);
return str.equals("")? defaultValue : str;
}
public static char readConfirmSelection() {
char c;
for (; ; ) {
String str = readKeyBoard(1, false).toUpperCase();
c = str.charAt(0);
if (c == 'Y' || c == 'N') {
break;
} else {
System.out.print("选择错误，请重新输入：");
}
}
return c;
}
private static String readKeyBoard(int limit, boolean blankReturn) {
String line = "";
while (scanner.hasNextLine()) {
line = scanner.nextLine();
if (line.length() == 0) {
if (blankReturn) return line;
else continue;
}
if (line.length() < 1 || line.length() > limit) {
System.out.print("输入长度（不大于" + limit + "）错误，请重新输入：");
continue;
}
break;
}
return line;
}
}
2.5 服务实现入口
CustomerService.java
package com.atguigu.cms.service;
import com.atguigu.cms.dao.CustomerDao;
import com.atguigu.cms.javabean.Customer;
import com.atguigu.cms.utils.JdbcUtil;
import java.sql.SQLException;
import java.util.List;
/**
* 这是一个具有管理功能的功能类. 内部数据不允许外部随意修改, 具有更好的封装性.
*/
public class CustomerService {
private CustomerDao customerDao = new CustomerDao();
/**
* 用途：返回所有客户对象
* 返回：集合
*/
public List<Customer> getList() {
try {
return customerDao.getList();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 用途：添加新客户
* 参数：customer指定要添加的客户对象
*/
public void addCustomer(Customer customer) {
try {
JdbcUtil.getConnection().setAutoCommit(false);
customerDao.addCustomer(customer);
JdbcUtil.getConnection().commit();
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
/**
* 用途：返回指定id的客户对象记录
* 参数： id 就是要获取的客户的id号.
* 返回：封装了客户信息的Customer对象
*/
public Customer getCustomer(int id) {
try {
return customerDao.getOne(id);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 修改指定id号的客户对象的信息
*
* @param id 客户id
* @param cust 对象
* @return 修改成功返回true, false表明指定id的客户未找到
*/
public boolean modifyCustomer(int id, Customer cust) {
int rows = 0;
try {
JdbcUtil.getConnection().setAutoCommit(false);
rows = customerDao.updateById(cust);
JdbcUtil.getConnection().commit();
} catch (SQLException e) {
throw new RuntimeException(e);
}
// 返回修改成功
if (rows == 0) {
return false;
}
return true;
}
/**
* 用途：删除指定id号的的客户对象记录
* 参数： id 要删除的客户的id号
* 返回：删除成功返回true；false表示没有找到
*/
public boolean removeCustomer(int id) {
int rows = 0;
try {
JdbcUtil.getConnection().setAutoCommit(false);
rows = customerDao.removeById(id);
JdbcUtil.getConnection().commit();
} catch (SQLException e) {
throw new RuntimeException(e);
}
if (rows == 0) {
return false;
}
return true;
}
}
2.6 JavaBean对应的Dao实现
CustomerDao.java
package com.atguigu.cms.dao;
import com.atguigu.cms.javabean.Customer;
import com.atguigu.cms.utils.BaseDao;
import java.sql.SQLException;
import java.util.List;
/**
* @Title: CustomerDao
* @Package: com.atguigu.cms.dao
* @Description:
* @Author: untifa
* @Date: 2023/3/26 - 13:15
*/
public class CustomerDao extends BaseDao {
public List<Customer> getList() throws Exception {
String sql = "SELECT * FROM t_customer;";
List<Customer> customers = query(Customer.class, sql);
return customers;
}
public Customer getOne(int id) throws Exception {
String sql = "SELECT * FROM t_customer WHERE id = ? ;";
List<Customer> customers = query(Customer.class, sql, id);
return customers.get(0);
}
public void addCustomer(Customer customer) throws SQLException {
String sql = "INSERT INTO t_customer(name,gender,age,salary,phone) values( ?, ?, ?, ?, ?) ; ";
update(sql, customer.getName(), customer.getGender(), customer.getAge(), customer.getSalary(), customer.getPhone());
}
public int updateById(Customer cust) throws SQLException {
String sql = "UPDATE t_customer SET name = ?, gender = ?, age = ?, salary = ?, phone = ? WHERE id = ? ;";
int update = update(sql, cust.getName(), cust.getGender(), cust.getAge(), cust.getSalary(), cust.getPhone(), cust.getId());
return update;
}
public int removeById(int id) throws SQLException {
String sql = "DELETE FROM t_customer WHERE id = ? ;";
int update = update(sql, id);
return update;
}
}
2.7 durid.properties配置文件
driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://192.168.101.130:3306/atguigu
username=root
password=root
maxActive=100
initialSize=10
defaultAutoCommit=true
3. 实现客户信息增删改查的功能
