JSP、Servlet中的相对路径和绝对路径

网络整理 - 07-27

用servlet将jsp文件内容转为html。代码如下:

package examples;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
 
public class ToHtml extends HttpServlet {
 private static final String CONTENT_TYPE = "text/html; charset=GBK";
 // Initialize global variables
 public void init() throws ServletException {
 }
 
 // Process the HTTP Get request
 public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
      response.setContentType(CONTENT_TYPE);
      service(request, response);
  /**
   * 只有成功初始化后此方法才能被调用处理用户请求。前一个参数提供访问初始请求数据的方法和字段,
   * 后一个提供servlet构造响应的方法。
   */
 }
 // Process the HTTP Post request
 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  doGet(request, response);
 }
 public void destroy() {
 }
 public void service(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
 
  ServletContext sc = getServletContext();
  String url = "/index.jsp";
 
  String name = "index.htm"; // 这是生成的html文件名
   
  String pName = "e:\\Tomcat 5.5\\webapps\\jspTohtml\\index.htm"; // 生成html的完整路径
  RequestDispatcher rd = sc.getRequestDispatcher(url);
  final ByteArrayOutputStream os = new ByteArrayOutputStream();
  final ServletOutputStream stream = new ServletOutputStream() {
   public void write(byte[] data, int offset, int length) {
    os.write(data, offset, length);
   }
   public void write(int b) throws IOException {
    os.write(b);
   }
  };
  final PrintWriter pw = new PrintWriter(new OutputStreamWriter(os));
  HttpServletResponse rep = new HttpServletResponseWrapper(response) {
   public ServletOutputStream getOutputStream() {
    return stream;
   }
   public PrintWriter getWriter() {
    return pw;
   }
  };
  rd.include(request, rep);
  pw.flush();
  FileOutputStream fos = new FileOutputStream(pName); // 把jsp输出的内容写到指定路径的htm文件中
  os.writeTo(fos);
  fos.close();
  response.sendRedirect(name); // 书写完毕后转向htm页面
 }
}

在web.xml文件中配置:

< servlet>    < servlet-name>Tohtml< /servlet-name>    < servlet-class>examples.ToHtml< /servlet-class>< /servlet> < servlet-mapping>    < servlet-name>Tohtml< /servlet-name>    < url-pattern>/Tohtml< /url-pattern>  < /servlet-mapping>

下面是用来测试的index.jsp:

< %@ page contentType="text/html; charset=gb2312" %>< html>  < head>    < title>Cache Filter Test< /title>   < meta http-equiv="Content-Type" content="text/html; charset=gb2312">  < /head>  < body>简单测试:s=< % int s=0; // mock time-consuming code for (int i=0;i< 1000;i++) {   for (int j=0;j< 1000;j++) {     s=s+j;   } }out.print(s);%>  < /body>< /html>