Jsp Servlet配置过滤器Filter

欢迎技术交流。 QQ：138986722

首先创建好Servlet——我在这里创建了一个BaseServlet(通用Servlet)这样可以避免创建太多的Servlet：

package servlet; import java.io.IOException; import java.lang.reflect.Method; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class BaseServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { /*获取方法名称*/ String methodName = request.getParameter("method"); /*获取当前对象的类型对象*/ Class<?> classType = this.getClass(); // System.out.println(classType); /*获取方法对象 1,方法名称.2,方法参数的类型*/ Method method = classType.getDeclaredMethod(methodName, new Class[]{HttpServletRequest.class, HttpServletResponse.class}); /*执行方法 * this:调用哪个对象的方法 * Object[]:参数*/ method.invoke(this, new Object[]{request, response}); } catch (Exception e) { System.out.println(e.getMessage()); } } }

创建好过后、那么在以后你所创建的Servlet中都要继承这个Servlet在页面访问的时候、需要加上method参数：

package servlet; import java.io.IOException; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import filter.CodingConvert; @SuppressWarnings("all") public class UserAction extends BaseServlet { public void getUser(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{ String pass = request.getParameter("pass"); CodingConvert cod = new CodingConvert(); String name = cod.toUT(request.getParameter("name")); request.setAttribute("list", name); //response.sendRedirect("index.jsp"); //此跳转方法只能取得在url中带parameter或Session范围内的值 RequestDispatcher dispatcher = request.getRequestDispatcher("index.jsp"); dispatcher .forward(request, response); } } //下面是页面 <form name="form1" action="userAction?method=getUser" method="post"> //其中userAction是我在Web.xml文件中定义的Servlet名称

其中UserAction中用到的字符编码转换方法类。我也不知道为什么、所有的东西都设置好了、连Tomcat的配置文件都改了还是不能解决我的乱码问题、于是用了这个方法：

package filter; public class CodingConvert { public CodingConvert(){ } public String toUT(String uniStr){ String gbStr = ""; if(uniStr == null){ uniStr = ""; } try{ byte[] tempByte = uniStr.getBytes("ISO8859_1"); gbStr = new String(tempByte,"UTF-8"); } catch(Exception ex){ } return gbStr; } public String toUni(String gbStr){ String uniStr = ""; if(gbStr == null){ gbStr = ""; } try{ byte[] tempByte = gbStr.getBytes("UTF-8"); uniStr = new String(tempByte,"ISO8859_1"); }catch(Exception ex){ } return uniStr; } }

 

 

过滤器类(实现Filter接口)：

package filter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class FilterImpl implements Filter { public void destroy() { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { //设置编码方式 request.setCharacterEncoding("UTF-8"); chain.doFilter(request,response); //这行意思是代码设置完毕，继续执行 } public void init(FilterConfig filterConfig) throws ServletException { } }

 

我的Web.xml文件：

<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <servlet-name>BaseServlet</servlet-name> <servlet-class>servlet.BaseServlet</servlet-class> </servlet> <servlet> <servlet-name>UserAction</servlet-name> <servlet-class>servlet.UserAction</servlet-class> </servlet> <servlet-mapping> <servlet-name>BaseServlet</servlet-name> <url-pattern>/hzw</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>UserAction</servlet-name> <url-pattern>/userAction</url-pattern> </servlet-mapping> <!-- 过滤器 --> <filter> <filter-name>myFtiler</filter-name> <filter-class>filter.FilterImpl</filter-class> </filter> <filter-mapping> <filter-name>myFtiler</filter-name> <servlet-name>BaseServlet</servlet-name> <servlet-name>UserAction</servlet-name> </filter-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>

 

参考资源：http://blog.csdn.net/wangmin326/archive/2010/07/15/5736854.aspx

上面这个资源中对Filter类跟xml配置文件都有很详细的讲解。