本片文章是对上一篇文章中的事务的例子的功能扩写，用以加深理解，以及代码的熟练度：
（1）数据库表
数据：
（2）引入数据库连接jar包
（3）工具类：
package org.jdbc.util;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
//操作数据库的工具类
public class DBUtil {
// 私有化构造方法
private DBUtil() {
}
private static String url = null;
private static String user = null;
private static String password = null;
static {
try {
Class.forName("com.mysql.jdbc.Driver");
Properties pro = new Properties();
pro.load(new FileInputStream("src/jdbc.properties"));
url = pro.getProperty("url");
user = pro.getProperty("user");
password = pro.getProperty("password");
} catch (Exception e) {
e.printStackTrace();
}
}
// 读取外部属性文件获取连接对象，需手动输入url
public static Connection getConnection1(String url) {
Properties pro = new Properties();
Connection conn = null;
InputStream input = null;
try {
input = new FileInputStream("E:" + File.separator
+ "JDBC.properties");
pro.load(input);
conn = DriverManager.getConnection(url, pro);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
// 读取工程下的配置文件，获取连接对象参数，不需手动输入url
public static Connection getConnection2() throws SQLException {
Connection conn = DriverManager.getConnection(url, user, password);
return conn;
}
// 释放全部资源
public static void closeAll(Connection conn, Statement stat, ResultSet rs)
throws SQLException {
if (conn != null) {
conn.close();
}
if (stat != null) {
stat.close();
}
if (rs != null) {
rs.close();
}
}
// 释放所用资源
public static void closePart(Connection conn, Statement stat)
throws SQLException {
if (conn != null) {
conn.close();
}
if (stat != null) {
stat.close();
}
}
}
（4）编写代码：
package org.jdbc.transcation;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;
import org.jdbc.util.DBUtil;
public class AccountDemo {
// 主方法控制运行方向
public static void main(String[] args) {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
Scanner scan = new Scanner(System.in);
System.out.println("欢迎来到模拟银行界面");
while (true) {
System.out.print("请输入你的选择（1 转账 2 查询 3存款 4取款 5开户 8退出）：");
int chioce;
try {
chioce = scan.nextInt();
if (chioce == 1 | chioce == 2 | chioce == 3 | chioce==4 | chioce==5 |chioce == 8) {
switch (chioce) {
case 1: // 转账
System.out.print("请输入转出账户姓名：");
String fromName = br.readLine();
System.out.print("请输入转入账户姓名：");
String toName = br.readLine();
System.out.print("请输入转账金额：");
int money = scan.nextInt();
boolean flag = transFerMoney(fromName, toName, money);
if (flag) {
System.out.println("转账成功");
showBalance(toName);
showBalance(fromName);
} else {
System.out.println("请检查你输入的信息是否正确，请输入正确的信息，重新办理此业务，谢谢！");
}
break;
case 2: // 查询
System.out.print("请选择 （1：查询全部账户信息\t2：个人账户信息）：");
int chioce1 = scan.nextInt();
if (chioce1 == 1 | chioce1 == 2) {
switch (chioce1) {
case 1: // 查询全部账户
selectAll();
break;
case 2: // 查询个人账户
System.out.print("请输入查询账户姓名：");
String balName = br.readLine();
selectPart(balName);
break;
}
} else {
System.out.println("你的选项错误，请重新输入");
}
break;
case 3: // 存款
System.out.print("请输入存款账户名：");
String savName = br.readLine();
System.out.print("请输入存款金额：");
int savMoney = scan.nextInt();
boolean isSave = saveMoney(savName, savMoney);
if (isSave) {
System.out.println("存款成功");
showBalance(savName);
} else {
System.out.println("你输入的账户信息有误，存款失败..");
}
break;
case 4: // 取款
System.out.print("请输入取款账户名：");
String draName = br.readLine();
System.out.print("请输入取款金额：");
int draMoney = scan.nextInt();
boolean isDraw = drawMoney(draName, draMoney);
if (isDraw) {
System.out.println("取款成功");
showBalance(draName);
} else {
System.out.println("你输入的账户信息有误，取款失败..");
}
break;
case 5: // 取款
System.out.print("请输入开户账户名：");
String opName = br.readLine();
System.out.print("请输入开户存款金额：");
int opBalance = scan.nextInt();
boolean isOpen = openAccount(opName, opBalance);
if (isOpen) {
System.out.println("恭喜你，开户成功");
System.out.println("当前账户信息：");
selectPart(opName);
} else {
System.out.println("Sorry，发生异常，你开户失败..");
}
break;
case 8: // 退出本系统
System.out.println("谢谢你的光临，再见！！");
System.exit(0);
}
} else {
System.out.println("你的选项错误，请重新输入");
}
} catch (IOException e) {
System.out.println("你有非法操作，产生异常现象："+e.getMessage());
}
}
}
// 转钱方法
@SuppressWarnings("resource")
public static boolean transFerMoney(String fromName, String toName,
int money) {
boolean flag = false;
PreparedStatement ps = null;
Connection conn = null;
ResultSet rs=null;
try {
conn = DBUtil.getConnection2();
String sql="select * from account where name=?";
ps=conn.prepareStatement(sql);
ps.setString(1, fromName);
rs=ps.executeQuery();
boolean flag1=false;
flag1= rs.next();
ps.close();
ps=conn.prepareStatement(sql);
ps.setString(1, fromName);
rs=ps.executeQuery();
boolean flag2=false;
flag2= rs.next();
ps.close();
if((flag1 && flag2)!=false){
conn.setAutoCommit(false);// 取消自动提交
String sql1 = "update account set balance=balance-? where name=?";
String sql2 = "update account set balance=balance+? where name=?";
ps = conn.prepareStatement(sql1);
ps.setInt(1, money);
ps.setString(2, fromName);// 转出
ps.executeUpdate();
ps.close();
ps = conn.prepareStatement(sql2);
ps.setInt(1, money);
ps.setString(2, toName);// 转入
ps.executeUpdate();
conn.commit();// 提交事务
flag = true;
}else{
System.out.println("Sorry,你输入的账户有误，不能进行转账处理");
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeAll(conn, ps,rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
return flag;
}
// 全部账户查询方法信息
public static void selectAll() {
PreparedStatement ps = null;
Connection conn = null;
ResultSet rs = null;
try {
conn = DBUtil.getConnection2();// 建立连接
String sql = "select * from account";
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
System.out.println("全部账户信息查询结果为：");
System.out.println("编号\t姓名\t账户余额");
while (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int balance = rs.getInt("balance");
System.out.println(id + "\t" + name + "\t" + balance);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeAll(conn, ps, rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
// 查询单人账户信息
@SuppressWarnings("resource")
public static void selectPart(String balName) {
PreparedStatement ps = null;
Connection conn = null;
ResultSet rs = null;
try {
conn = DBUtil.getConnection2();// 建立连接
String sql3 = "select * from account where name=?";
ps = conn.prepareStatement(sql3);
ps.setString(1, balName);
rs = ps.executeQuery();
boolean flag = rs.next();
if (flag == true) {
System.out.println(balName + "账户信息查询结果为：");
System.out.println("编号\t姓名\t账户余额");
rs = ps.executeQuery();
while (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int balance = rs.getInt("balance");
System.out.println(id + "\t" + name + "\t" + balance);
}
} else {
System.out.println("你输入的 账户信息不存在，请重新输入..");
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeAll(conn, ps, rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
// 存钱方法
public static boolean saveMoney(String saveName, int savMoney) {
boolean flag = false;
Connection conn = null;
PreparedStatement ps = null;
String sql6 = "update account set balance=balance+? where name=?";
int count = 0;
try {
conn = DBUtil.getConnection2();
ps = conn.prepareStatement(sql6);
ps.setInt(1, savMoney);
ps.setString(2, saveName);
count = ps.executeUpdate();
if (count != 0) {
flag = true;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closePart(conn, ps);
} catch (SQLException e) {
e.printStackTrace();
}
}
return flag;
}
// 取钱方法
public static boolean drawMoney(String drawName, int draMoney) {
boolean flag = false;
Connection conn = null;
PreparedStatement ps = null;
String sql7 = "update account set balance=balance-? where name=?";
int count = 0;
try {
conn = DBUtil.getConnection2();
ps = conn.prepareStatement(sql7);
ps.setInt(1, draMoney);
ps.setString(2, drawName);
count = ps.executeUpdate();
if (count != 0) {
flag = true;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closePart(conn, ps);
} catch (SQLException e) {
e.printStackTrace();
}
}
return flag;
}
// 建立新的账户
public static boolean openAccount(String opName, int opBalance) {
boolean flag = false;
Connection conn = null;
PreparedStatement ps = null;
String sql9 = "insert into account(name,balance) values(?,?)";
int count = 0;
try {
conn = DBUtil.getConnection2();
ps = conn.prepareStatement(sql9);
ps.setString(1, opName);
ps.setInt(2, opBalance);
count = ps.executeUpdate();
if (count != 0) {
flag = true;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closePart(conn, ps);
} catch (SQLException e) {
e.printStackTrace();
}
}
return flag;
}
//显示余额方法
@SuppressWarnings("resource")
public static void showBalance(String showName) {
PreparedStatement ps = null;
Connection conn = null;
ResultSet rs = null;
try {
conn = DBUtil.getConnection2();// 建立连接
String sql10 = "select balance from account where name=?";
ps = conn.prepareStatement(sql10);
ps.setString(1, showName);
rs = ps.executeQuery();
rs = ps.executeQuery();
while (rs.next()) {
int shBalance = rs.getInt("balance");
System.out.println(showName + "账户当前 余额为："+shBalance);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeAll(conn, ps, rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
运行结果：