web 应用中访问 Spring 具体实现

user=LF
password=LF
jdbcUrl=jdbc:oracle:thin:@localhost:1521:orcl
driverClass=oracle.jdbc.driver.OracleDriver

initialPoolSize=15
maxPoolSize=30
minPoolSize=5

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop.xsd"> 

    <!-- 配置自动扫描的包 -->
    <context:component-scan base-package="com.zr.trasaction"></context:component-scan>

    <!-- 引用外部文件 -->
    <context:property-placeholder location="classpath:db.properties"/>

    <!-- 配置dataSource -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${user}"></property>
        <property name="password" value="${password}"></property>
        <property name="jdbcUrl" value="${jdbcUrl}"></property>
        <property name="driverClass" value="${driverClass}"></property>

        <property name="initialPoolSize" value="${initialPoolSize}"></property>
        <property name="maxPoolSize" value="${maxPoolSize}"></property>
        <property name="minPoolSize" value="${minPoolSize}"></property>
    </bean>
    <!-- 配置jdbcTemplate -->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <!-- 配置事务声明方式 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">

  <context-param>
      <param-name>contextConfiguration</param-name>
      <param-value>/WEB-INF/applicationContext.xml</param-value>
  </context-param>

  <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener
      </listener-class>
  </listener>

  <servlet>
    <servlet-name>AServlet</servlet-name>
    <servlet-class>com.zr.trasaction.servlet.AServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>AServlet</servlet-name>
    <url-pattern>/AServlet</url-pattern>
  </servlet-mapping>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">

  <context-param>
      <param-name>contextConfiguration</param-name>
      <param-value>/WEB-INF/applicationContext.xml</param-value>
  </context-param>

  <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener
      </listener-class>
  </listener>

  <servlet>
    <servlet-name>AServlet</servlet-name>
    <servlet-class>com.zr.trasaction.servlet.AServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>AServlet</servlet-name>
    <url-pattern>/AServlet</url-pattern>
  </servlet-mapping>

</web-app>

package com.zr.trasaction.entity;

public class Amount {

    private String user;//用户名
    private double money;//金额
    public String getUser() {
        return user;
    }
    public void setUser(String user) {
        this.user = user;
    }
    public double getMoney() {
        return money;
    }
    public void setMoney(double money) {
        this.money = money;
    }
    public Amount() {
        super();
    }
    public Amount(String user, double money) {
        super();
        this.user = user;
        this.money = money;
    }
    @Override
    public String toString() {
        return "Amount [user=" + user + ", money=" + money + "]";
    }

}

package com.zr.trasaction.entity;

public class BalanceException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    public BalanceException() {
        super();
    }

    public BalanceException(String message) {
        super(message);
    }

    public BalanceException(String message, Throwable cause) {
        super(message, cause);
    }

    public BalanceException(Throwable cause) {
        super(cause);
    }

    protected BalanceException(String message, Throwable cause,
                               boolean enableSuppression,
                               boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }
}

package com.zr.trasaction.dao;

public interface AmountDao {

    /**
     * 转出钱
     * @return
     */
    public boolean decreaseMoney(String username,double money) ;

    /**
     * 转入钱
     * @return
     */
    public boolean increaseMoney(String username,double money);

}

package com.zr.trasaction.daoImpl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

import com.zr.trasaction.dao.AmountDao;

@Repository
public class AmountDaoImpl implements AmountDao {
    @Autowired(required=true)
    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    @Override
    public boolean decreaseMoney(String username, double money) {

        String sql = "UPDATE TEST SET MONEY=MONEY-? WHERE USERNAME=?";
        int i = -1;
        i = jdbcTemplate.update(sql,money, username);
        if(i>0){
            return true;
        }
        return false;
    }

    @Override
    public boolean increaseMoney(String username, double money) {
        String sql = "UPDATE TEST SET MONEY=MONEY+? WHERE USERNAME=?";
        int i = -1;
        i = jdbcTemplate.update(sql,money, username);
        if(i>0){
            return true;
        }
        return false;
    }

}

package com.zr.trasaction.Service;

import com.zr.trasaction.entity.Amount;

public interface AmountService {

    /**
     * 转账业务
     * @param desAmount 扣钱的账户
     * @param incAmount    增加的账户
     * @param money 转账的金额
     * @return
     */
    public boolean transferMoneyService(Amount desAmount,Amount incAmount,double money);

}

package com.zr.trasaction.ServiceImpl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

import com.zr.trasaction.Service.AmountService;
import com.zr.trasaction.daoImpl.AmountDaoImpl;
import com.zr.trasaction.entity.Amount;
import com.zr.trasaction.entity.BalanceException;

@Service("amountServiceImpl")
public class AmountServiceImpl implements AmountService {
    @Autowired(required=true)
    private AmountDaoImpl amountDaoImpl;
    @Autowired(required=true)
    private JdbcTemplate jdbcTemplate;

    public void setAmountDaoImpl(AmountDaoImpl amountDaoImpl) {
        this.amountDaoImpl = amountDaoImpl;
    }

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }
    /**
     *    REQUIRED（默认值）:在有transaction状态下执行;如当前没有transaction，则创建新的transaction
     * 只读事务属性readOnly=true: 表示这个事务只读取数据但不更新数据, 这样可以帮助数据库引擎优化事务
     * 超时事务属性timeout=3: 事务在强制回滚之前可以保持多久. 这样可以防止长期运行的事务占用资源.单位为秒,一般不设置，使用默认的
     * noRollbackForClassName={"BalanceException"} 发生BalanceException异常不回滚
     */
    @Transactional(propagation=Propagation.REQUIRED,isolation=Isolation.READ_COMMITTED,readOnly=true,timeout=3/*,noRollbackForClassName={"BalanceException"}*/)
    @Override
    public boolean transferMoneyService(Amount desAmount, Amount incAmount,
            double money) {
        String sql = "SELECT MONEY FROM TEST WHERE USERNAME=?";
        double balance = jdbcTemplate.queryForObject(sql, Double.class, desAmount.getUser());

        boolean success1 = amountDaoImpl.decreaseMoney(desAmount.getUser(), money);
        boolean success2 = amountDaoImpl.increaseMoney(incAmount.getUser(), money);

        if(balance < money){
            throw new BalanceException("余额不足");
        }
        return success1 && success2;
    }

}

package com.zr.trasaction.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.zr.trasaction.Service.AmountService;
import com.zr.trasaction.entity.Amount;

public class AServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext());
        System.out.println(wac);
        Amount desAmount = new Amount("lf", 0);
        Amount incAmount = new Amount("tl", 0);
        AmountService impl = (AmountService) wac.getBean("amountServiceImpl");
        boolean isSuccess = impl.transferMoneyService(desAmount, incAmount, 10);
        System.out.println(isSuccess);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

    }

}