Posted on 2006-12-12 09:11
兵临城下 阅读(301)
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Java EE
创建filter的类（引用自
T-shirt）
package testfilterservlet;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class MyFirstFilter implements Filter {
private FilterConfig config;
public void init(FilterConfig filterConfig) throws ServletException {
this.config = filterConfig;
System.out.println("MyFirstFilter init!");
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
String myName = (String)request.getParameter("name");
if(myName.equals("lsr")){
System.out.print("lsr");
chain.doFilter(request,response); //继续响应下一个filter或者servlet
}else{
System.out.print("not lsr");
RequestDispatcher dispatcher = request.getRequestDispatcher("/testForm/testform1.html");
dispatcher.forward(request,response);
}
}
public void destroy() {
// TODO 自动生成方法存根
System.out.println("MyFirstFilter destroy!");
}
}
然后注册(简写)
<web-app>
<filter>
<filter-name>MyFirstFilter</filter-name>
<filter-class>testfilterservlet.MyFirstFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>MyFirstFilter</filter-name>
<servlet-name>PrintLog</servlet-name> //这里可以使用 url-pattern
</filter-mapping>
<servlet>
<description></description>
<display-name>PrintLog</display-name>
<servlet-name>PrintLog</servlet-name>
<servlet-class>testservlet.PrintLog</servlet-class>
<init-param>
<param-name>des</param-name>
<param-value>this is a test</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>PrintLog</servlet-name>
<url-pattern>/PrintLog</url-pattern>
</servlet-mapping>
</web-app>