Question

您好，我正在研究JSP Servlet项目，因为我创建了一个CommonServlet类，从我转发请求到重定向JSP页面，我的代码如下所示

Class CommonServlet extends HTTPServlet{
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
super.doGet(req, resp);
String url="/file/myfolder/jsp/login.jsp";
RequestDispatcher  requestDispatcher = req.getRequestDispatcher(url);
requestDispatcher.forward(req, resp);
 }
}

Web.xml

<servlet>
  <servlet-name>common</servlet-name>
  <servlet-class>com.server.CommonServlet</servlet-class>
</servlet>
<servlet-mapping>
  <servlet-name>common</servlet-name>
  <url-pattern>/common/*.jsp</url-pattern>
</servlet-mapping>

但是这不起作用它会为所有其他文件获得相同的公共路径。有谁能够帮我？

Answer 1

首先，我假设您的index.jsp

中有一些web.xml映射

<welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

所以首先服务器读取web.xml并在你执行

时加载index.jsp

http://localhost:8080/yourProjectName

在index.jsp中有一个像这样调用servlet的表单

<form method="get" action="common" name="form">
<input type="submit" value="LOGIN"/>
</form>

最后在yourServletClass的doGet()中将此重定向到login.jsp（假设您的login.jsp位于webcontent/login.jsp）

RequestDispatcher rd=req.getRequestDispatcher("login.jsp");
rd.include(request,response);

修改：尝试这样的事情将您在web.xml中的网址映射更改为

<url-pattern>/myservlet</url-pattern>

在web.xml

中配置过滤器

<filter>
    <filter-name>yourFilter</filter-name>
    <filter-class>org.yourpackage.YourFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>yourFilter</filter-name>
    <url-pattern>/common/*</url-pattern> 
</filter-mapping>

然后是过滤类

public class YourFilter implements javax.servlet.Filter {

@Override
public void destroy() {
}

@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain fc) 
      throws IOException, ServletException {

    HttpServletRequest request = (HttpServletRequest) req;
    String url = request.getRequestURL().toString();
    if(url.endsWith(".jsp")) {
      RequestDispatcher dispatcher = request.getRequestDispatcher("/myserlvet");
        dispatcher.forward(req, res);
    }
}

@Override
public void init(FilterConfig fc) throws ServletException {

}}

RequestDispatcher.forward（req，res）无效

1 个答案: