与数据库建立连接的银行取钱存钱，数据库实时更新用户信息2(使用封装了对数据库增加、修改、删除、查询的DBUtils工具类)
前言
步骤：
1.加载mysql-connector-java-5.1.7-bin.jar，commons-dbutils-1.4.jar，c3p0- 0.9.1.2.jar架包并build path
2.src中加载c3p0-config.xml配置文件
3.编写DBUtils类
4.编写javabean类
DBUtils类
/**
* 封装使用c3p0数据池与数据库建立连接和不用数据池建立连接的，对数据经行增加、修改、删除和查询
* 注：读取资源配置文件、加载驱动类、与数据库建立连接都由数据池自动完成
* author 脱发的小白
*/
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import com.mchange.v2.c3p0.ComboPooledDataSource;
//DbUtils的工具类封装基本的增删改查
public class DBUtils {
//创建数据池
public static DataSource dataSource=new ComboPooledDataSource();
//获取数据池
public static DataSource getDatasource () {
return dataSource;
}
//数据池获取连接
public static Connection getConnection() throws Exception {
return dataSource.getConnection();
}
/**
* 封装为不用数据池的,增加、修改、删除
* sql:执行的数据库语句
* params：查询数据库语句是否有替换占位符的参数
*/
public static Integer executeUpateConnction(String sql,Object...params) throws Exception {
Connection connection=getConnection();
QueryRunner qr = new QueryRunner();
Integer result=0;
if(params==null) {
result=qr.update(connection, sql);
}
else {
result=qr.update(connection, sql, params);
}
return result;
}
/**
* 封装为数据池的增加、修改、删除
* sql:执行的数据库语句
* params：查询数据库语句是否有替换占位符的参数
*/
public static Integer executeUpateDatasource(String sql,Object ... params) throws Exception {
Integer result=0;
QueryRunner qr = new QueryRunner(DBUtils.getDatasource());
result=qr.update(sql, params);
return result;
}
/**
* 封装为DBUtils的查询，不用数据池获取数据库建立连接
* sql:执行的数据库语句
* params：查询数据库语句是否有替换占位符的参数
* cazz:是用来定义接收查询数据结果的存入类的对象中的类的类型
*/
public static <T> List<T> queryConnection(String sql,Class<T> cazz,Object ... params) throws Exception{
List<T> list=null;
Connection connection=null;
QueryRunner qr = new QueryRunner();
BeanListHandler<T> beanListHandler = new BeanListHandler<>(cazz);
if(params==null) {
qr.query(connection, sql, beanListHandler);
}
else {
qr.query(connection,sql, beanListHandler, params);
}
return list;
}
/**
* 封装为DBUtils的查询，使用数据池建立连接
* sql:执行的数据库语句
* params：查询数据库语句是否有替换占位符的参数
* cazz:是用来定义接收查询数据结果的存入类的对象中的类的类型
*
*/
public static <T> List<T> queryDatasource(String sql,Class<T> cazz,Object ... params) throws SQLException{
List<T> list=null;
QueryRunner qr=new QueryRunner(DBUtils.getDatasource());
BeanListHandler<T> beanListHandler = new BeanListHandler<>(cazz);
list= qr.query(sql, beanListHandler, params);
return list;
}
}
Account类
/**
* 与数据库建立连接的银行取钱存钱，数据库实时更新用户信息(使用封装了对数据库增加、修改、删除、查询的DBUtils工具类)
* @auther脱发的小白
*/
public class Account {
private String username;
private String password;
private String number;
private int balance;
public Account() {
super();
// TODO Auto-generated constructor stub
}
public Account(String username, String password, String number, int balance) {
super();
this.username = username;
this.password = password;
this.number = number;
this.balance = balance;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public int getBalance() {
return balance;
}
public void setBalance(int balance) {
this.balance = balance;
}
// 注册账号，利用DBUtil将数据存入数据库中
public void register() throws Exception {
String sql = "insert into account (number,username,password,balance) values (?,?,?,?)";
Object[] params = {
this.number, this.username, this.password, this.balance };
Integer result = DBUtils.executeUpateDatasource(sql, params);
if (result == 1) {
System.out.println("用户注册成功");
}
if (result == 0) {
System.out.println("用户注册失败");
}
}
// 核对信息,卡号和密码正确返回true,否则返回false
public boolean check() throws SQLException {
boolean result=false;
String sql="select * from account where number=?";
Object[] params= {
this.number};
List<Account> list = DBUtils.queryDatasource(sql, Account.class, params);
Account account = list.get(0);
if(this.number.equals(account.number) & this.password.equals(account.password)) {
result=true;
}
else {
System.out.println("卡号和密码错误");
}
return result;
}
//查询余额
public Integer queryBalance() throws Exception {
Integer result=0;
if(this.check()) {
String sql="select balance from account where number=?;";
Object [] params= {
this.number};
List<Account> list = DBUtils.queryDatasource(sql, Account.class, params);
Account account = list.get(0);
int balance2 = account.balance;//数据库中用户中的余额
result=balance2;
}
return result;
}
//存钱
public void saveMoney(int mon) throws Exception {
Integer result=0;
if(this.check()) {
String sql="update account set balance=balance+? where number=?";
Object [] params= {
mon,this.number};
Integer res = DBUtils.executeUpateDatasource(sql, params);
if(res==1) {
result=this.queryBalance();
System.out.println("存钱成功");
System.out.println("余额为"+result);
}
if(res==0) {
System.out.println("存钱失败");
}
}
}
//取钱
public Integer drawMoney(int mon) throws Exception {
int result=0;
if(this.check()) {
String sql="update account set balance=balance-? where number=?";
Object [] params= {
mon,this.number};
Integer res = DBUtils.executeUpateDatasource(sql, params);
if(res==1) {
result=this.queryBalance();
System.out.println("取钱成功");
System.out.println("余额为"+result);
}
if(res==0) {
System.out.println("存钱失败");
}
}
return result;
}
}
测试类
public class Test {
public static void main(String[] args) throws Exception {
Account account1 = new Account("小敏", "5201314", "1003", 20000);
account1.register();
account1.saveMoney(1000);
account1.drawMoney(2000);
Account account2 = new Account("小孙", "100320", "653214", 500000);
account2.register();
account2.saveMoney(2000);
account2.drawMoney(1000);
}
}
结果展示
