java 将 spring bean 加载到 servlet 中
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load spring bean into a servlet
提问by ufk
There are many documentations out there on how to achieve this task but I still couldn't resolve my issue. I'm new to working with servlet so I probably missed something.
有很多关于如何完成这项任务的文档，但我仍然无法解决我的问题。我是 servlet 的新手，所以我可能错过了一些东西。
I use red5 that uses tomcat 6 to create a servlet that uses a spring bean that's of a MysqlDb class for database manipulations.
我使用使用 tomcat 6 的 red5 创建一个 servlet，该 servlet 使用属于 MysqlDb 类的 spring bean 进行数据库操作。
when I point to red5 using port 5080 it acts as a regular tomcat server and i can browse jsp and servlet pages.
当我使用端口 5080 指向 red5 时，它充当常规的 tomcat 服务器，我可以浏览 jsp 和 servlet 页面。
my web.xml contains the following relevant information:
我的 web.xml 包含以下相关信息：
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>fbauth</servlet-name>
<servlet-class>com.xpogames.FbAuth</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>fbauth</servlet-name>
<url-pattern>/fbauth</url-pattern>
</servlet-mapping>
my applicationContext.xml:
我的 applicationContext.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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<bean id="placeholderConfig" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="/WEB-INF/red5-web.properties" />
</bean>
<bean id="idDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName"><value>${db.driver}</value></property>
<property name="url"><value>${db.url}</value></property>
<property name="username"><value>${db.username}</value></property>
<property name="password"><value>${db.password}</value></property>
<property name="poolPreparedStatements"><value>true</value></property>
<property name="maxActive"><value>10</value></property>
<property name="maxIdle"><value>10</value></property>
</bean>
<bean id="MysqlDb" class="com.xpogames.MysqlDb">
<property name="idDataSource" ref="idDataSource"/>
</bean>
</beans>
my FbAuth servlet:
我的 FbAuth servlet：
package com.xpogames;
包 com.xpogames;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
public class FbAuth extends HttpServlet {
private static final long serialVersionUID = 1L;
public FbAuth() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
WebApplicationContext webApplicationContext = WebApplicationContextUtils.getRequiredWebApplicationContext(request.getSession().getServletContext());
MysqlDb mysqlDb = (MysqlDb)webApplicationContext.getBean("MysqlDb");
out.println(mysqlDb.testme());
out.println("Hello, world!");
out.close();
}
}
I get the following error:
我收到以下错误：
java.lang.IllegalStateException: Context attribute is not of type WebApplicationContext
I think I'm not fetching the spring bean correctly.
我想我没有正确获取春豆。
any ideas?
有任何想法吗？
thank you!
谢谢！
update
更新
this is my new init function:
这是我的新 init 函数：
public void init(ServletConfig config) throws ServletException {
super.init(config);
ServletContext servletContext = this.getServletContext();
this._context = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
}
thanks a lot! :)
多谢！:)
回答by Rajendra
I use the following in the init() method of the servlet. The init() method is called only once in a Servlets lifecycle.
我在 servlet 的 init() 方法中使用了以下内容。init() 方法在 Servlets 生命周期中只调用一次。
ApplicationContext context =
WebApplicationContextUtils.getRequiredWebApplicationContext(
this.getServletContext());
Also, do you have the "contextConfigLocation" in your web.xml?
另外，您的 web.xml 中有“contextConfigLocation”吗？
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:/**/spring-config.xml
</param-value>
</context-param>
回答by Femi
You may have multiple versions of Spring on your class path: check that you aren't accidentally loading 2 different Spring jars.
您的类路径上可能有多个版本的 Spring：检查您是否不小心加载了 2 个不同的 Spring jar。
回答by Nethaji Narasimalu
WebApplicationContext webApplicationContext = WebApplicationContextUtils.getWebApplicationContext(getServletContext());
webApplicationContext .getBean("Name")
