servlet注入spring管理

最新推荐文章于 2020-10-18 09:34:01 发布

技术宝哥

最新推荐文章于 2020-10-18 09:34:01 发布

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本文详细介绍了如何将业务Servlet配置为Spring的bean，并通过代理Servlet进行初始化和调用，从而实现业务逻辑的注入和执行。通过示例代码展示了业务Servlet的写法、配置步骤以及web.xml中的配置，旨在提供一种有效的Spring与Servlet集成解决方案。

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思路：把servlet配置为spring的bean，就可以实现其他bean的注入，然后使用代理servlet来辅助配置和运行：

一、代理servlet的写法：

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.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
/**
 * Funshion Author: gongpeibao
 * 代理Servlet
 */
public class HttpServletProxy extends HttpServlet {

 private static final long serialVersionUID = -7208519469035631940L;
 Log logger = LogFactory.getLog(HttpServletProxy.class);
 private String targetServlet;
 private HttpServlet proxy;

 public void init() throws ServletException {
  this.targetServlet = getInitParameter("targetServlet");
  getServletBean();
  proxy.init(getServletConfig());
  logger.info(targetServlet + " was inited by HttpServletProxy  successfully......");
 }
 /**
  * 获取真实业务servlet
  */
 private void getServletBean() {
  WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
  this.proxy = (HttpServlet) wac.getBean(targetServlet);
 }

 @Override
 public void service(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException, RuntimeException {
  proxy.service(request, response);
 }
}

二、业务servlet的写法：

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class UserCheckServlet extends HttpServlet {

    /**
     * random serialVersionUID
     */

    private static final long serialVersionUID = 3075635113536622929L;
    private UserService userService;(UserService 是spring托管的bean，通过set方法注入)

    public void setUserService (UserService userService) {
        this.userService = userService;
    }

    public UserCheckServlet() {
        super();
    }

    public void init() throws ServletException {
        super.init();
    }

    @Override
    public void service(HttpServletRequest httpServletRequest, HttpServletResponse 
        httpServletResponse)

            throws ServletException, IOException, RuntimeException {

        ....
        ....

        userService.getUserByCode();(注入后bean的使用)

        ....
        ....
    }   
}

三、业务serlvet配置为spring的bean:

四、web.xml中业务servlet的配置：

<servlet>

        <servlet-name>UserCheckProxy</servlet-name>
        <servlet-class>com.XXX.xxxx.web.HttpServletProxy</servlet-class>
        <init-param>
            <param-name>targetServlet</param-name>
            <param-value>userCheckServlet</param-value> <--(业务servlet配置为spring的bean时的名字)-->
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>UserCheckProxy</servlet-name>
        <url-pattern>/UserCheck</url-pattern>
    </servlet-mapping>