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張誌宇 SERVELET JSP學習講義-HelloWorldServlet_2
接著 我的第一個Servlet程序，為了測試一下瀏覽器到底是get還是post方法接收信息，修改代碼如下：
package com.zzk.cn;
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;
public class HelloWorldServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("dopost...");
//super.doPost(req, resp);
}
/**
*
*/
private static final long serialVersionUID = 1L;//父類或者父類的父類實現了序列化的接口
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("doget....");
PrintWriter out=resp.getWriter();
out.println("<html><head></head><body><center><font color='red'>HelloWorldServlet!</font></center></body></html>");
out.flush();//清理
out.close();//關閉
}
}
寫一段html代碼：
<form action=https://localhost:8080/my/HelloWorldServlet method=get> <input type=text name=test> <input type=submit value="提交"> </form>
運行tomcat，打開該html文件後，點擊提交按鈕，會自動進入
<html><head></head><body><center><font color='red'>HelloWorldServlet!</font></center></body></html>的HTML頁麵
同時，tomcat的DOS窗口會顯示doget...一次
但是此時，將html代碼替換為dopost方法，如下：
<form action=https://localhost:8080/my/HelloWorldServlet method=post> <input type=text name=test> <input type=submit value="提交"> </form>
通過此html頁麵打開的新頁麵無內容，tomcat裏顯示dopost...一次
我們再來修改servlet代碼：
package com.zzk.cn;
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;
public class HelloWorldServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("dopost...");
//super.doPost(req, resp);
doGet(req,resp);
}
/**
*
*/
private static final long serialVersionUID = 1L;//父類或者父類的父類實現了序列化的接口
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("doget....");
PrintWriter out=resp.getWriter();
out.println("<html><head></head><body><center><font color='red'>HelloWorldServlet!</font></center></body></html>");
out.flush();//清理
out.close();//關閉
}
}
這時頁麵內容顯示出來
<html><head></head><body><center><font color='red'>HelloWorldServlet!</font></center></body></html>
tomcat裏顯示
dopost...
doget....
接下來，重寫servlet
package com.zzk.cn;
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;
public class HelloWorldServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.service(req, resp);
//System.out.println("doget....");
PrintWriter out=resp.getWriter();
out.println("<html><head></head><body><center><font color='red'>HelloWorldServlet!</font></center></body></html>");
out.flush();//清理
out.close();//關閉
}
// @Override
// protected void doPost(HttpServletRequest req, HttpServletResponse resp)
// throws ServletException, IOException {
// // TODO Auto-generated method stub
// System.out.println("dopost...");
// //super.doPost(req, resp);
// doGet(req,resp);
// }
//
//
//
// @Override
// protected void doGet(HttpServletRequest req, HttpServletResponse resp)
// throws ServletException, IOException {
// // TODO Auto-generated method stub
// System.out.println("doget....");
// PrintWriter out=resp.getWriter();
// out.println("<html><head></head><body><center><font color='red'>HelloWorldServlet!</font></center></body></html>");
// out.flush();//清理
// out.close();//關閉
// }
/**
*
*/
private static final long serialVersionUID = 1L;//父類或者父類的父類實現了序列化的接口
}
然後index.html中get和post方法
<form action=https://localhost:8080/my/HelloWorldServlet method=get> <input type=text name=test> <input type=submit value="提交"> </form>
OR
<form action=https://localhost:8080/my/HelloWorldServlet method=post> <input type=text name=test> <input type=submit value="提交"> </form>
都可以顯示
最後更新：2017-04-02 22:16:10