servlet+spring测试Demo

      最近在学习熟悉WEB框架。搭建servlet+spring时，卡了很长时间。将遇到的问题记录下来，供以后使用。

参考URL：http://blog.csdn.net/xwl617756974/article/details/7451773

（本文内容只是按引用链接的步骤，进行的测试。非原创）

 

      平时使用spring框架时，总是和strusts或springMVC等MVC框架联用。想自己学习下只用spring框架的IOC，使用servlet来控制跳转。

 

　　实现的中心思想：给普通的Servlet提供一个代理类，用于依赖注入。注入好所有需要的属性后，再执行Servlet本身的doGet、doPost等方法。

 

以下直接贴代码备忘：

1.Servlet代理类。

package syh.servlet;

import java.io.IOException;

import javax.servlet.GenericServlet;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

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

public class DelegatingServletProxy extends GenericServlet {
    private String targetBean;
    private Servlet proxy;

    @Override
    public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException, IOException {
        proxy.service(arg0, arg1);
    }

    @Override
    public void init() throws ServletException {
        this.targetBean = this.getServletName();
        getServletBean();
        proxy.init(getServletConfig());
    }
   
    private void getServletBean() {
        WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
        this.proxy = (Servlet) wac.getBean(targetBean);
    }
   
}

2.编写Servlet类。

package syh;

import java.io.IOException;

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

import org.springframework.stereotype.Component;

import syh.service.UserAccount;

@Component
public class SpringServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    @Resource
    private UserAccount userAccount;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("aaaaaa");
        System.out.println(userAccount);
        userAccount.checkAccount("", "");
        super.doGet(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
        super.doPost(req, resp);
    }

}

3.编写Servlet中要注入的Service类。

接口：

package syh.service;

public interface UserAccount {
    public boolean checkAccount(String account, String password);
}
实现：

package syh.service.impl;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.annotation.Resource;

import org.apache.commons.dbcp.BasicDataSource;
import org.springframework.stereotype.Component;

import syh.service.UserAccount;

@Component
public class UserAccountImpl implements UserAccount {
    @Resource
    private BasicDataSource dataSource;

    @Override
    public boolean checkAccount(String account, String password) {
        System.out.println(dataSource);
       
        Connection actualCon = null;
        Statement statement = null;
        ResultSet resultSet = null;
        try {
            actualCon = dataSource.getConnection();
            statement = actualCon.createStatement();
            resultSet = statement.executeQuery("select * from user");
            while (resultSet.next()) {
                System.out.println(resultSet.getString(1) + "  " + resultSet.getString("name"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                resultSet.close();
                statement.close();
                actualCon.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
       
        return "admin".equals(account) && "123".equals(password);
    }

}

为了测试Servlet中注入的Service，是否可级联注入Service中引用的其他类。在Service实现类中注入了dataSource，并执行了查询数据库操作。

 

4.Spring配置文件。springDatasource.xml

<?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:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" 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-2.5.xsd 
    http://www.springframework.org/schema/context  
    http://www.springframework.org/schema/context/spring-context-2.5.xsd 
    http://www.springframework.org/schema/tx  
    http://www.springframework.org/schema/tx/spring-tx-2.5.xsd 
    http://www.springframework.org/schema/aop  
    http://www.springframework.org/schema/aop/spring-aop-2.5.xsd    
    ">
    <context:component-scan base-package="syh"></context:component-scan>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close">
        <property name="defaultAutoCommit" value="true" />
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/test" />
        <property name="username" value="root" />
        <property name="password" value="123456" />
        <!--initialSize: 初始化连接 -->
        <property name="initialSize" value="2" />
        <!--maxIdle: 最大空闲连接 -->
        <property name="maxIdle" value="5" />
        <!--minIdle: 最小空闲连接 -->
        <property name="minIdle" value="5" />
        <!--maxActive: 最大连接数量 -->
        <property name="maxActive" value="2" />
        <!--removeAbandoned: 是否自动回收超时连接 -->
        <property name="removeAbandoned" value="true" />
        <!--removeAbandonedTimeout: 超时时间(以秒数为单位) -->
        <property name="removeAbandonedTimeout" value="180" />
        <!--maxWait: 超时等待时间以毫秒为单位 6000毫秒/1000等于60秒 -->
        <property name="maxWait" value="3000" />
        <property name="validationQuery">
            <value>SELECT 1</value>
        </property>
        <property name="minEvictableIdleTimeMillis">
            <value>3600000</value>
        </property>
        <property name="timeBetweenEvictionRunsMillis">
            <value>600000</value>
        </property>
        <property name="testOnBorrow">
            <value>true</value>
        </property>
    </bean>

</beans>

 

开始测试时一直报加载springServlet错误，增加以下配置后解决：

<context:component-scan base-package="syh"></context:component-scan>

 

中间尝试过下面的配置，但是错误依旧。有空研究下

<context:component-scan base-package="syh.*"></context:component-scan>

 

5.配置web.xml。

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>servletTest</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
   
    <servlet> 
        <servlet-name>springServlet</servlet-name> 
        <servlet-class> 
            syh.servlet.DelegatingServletProxy
        </servlet-class> 
        <load-on-startup>1</load-on-startup> 
    </servlet> 
    <servlet-mapping> 
        <servlet-name>springServlet</servlet-name> 
        <url-pattern>/spring</url-pattern> 
    </servlet-mapping>
   
    <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
           classpath:springDatasource.xml
       </param-value>
  </context-param>
  <listener>
    <description>启动spring上下工厂的监听器</description>
    <listener-class>
          org.springframework.web.context.ContextLoaderListener
       </listener-class>
  </listener>
</web-app>

 

关键点：servlet-class要配置成servlet的代理类。DelegatingServletProx

 

配置完成。

 

测试时，从控制台输出可以看到注入成功，且读库操作成功。