void service() 方法会调用
protected void service(HttpServletRequest req, HttpServletResponse resp);
这个 service 方法会分发给 doGet 与 doPost , 所以一般都不直接写这个 service()
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
PrintWriter out = resp.getWriter(); // 这个打印流，自动 flush
out.println("<html><head><title></title></head><body>hello world a!!!</body></html>");
out.flush();
out.close();
}
/*
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
System.out.println("doPost...");
doGet(req, resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) // tomcat 帮忙调用这个 doGet这个方法
throws ServletException, IOException {
System.out.println("doGet...");
PrintWriter out = resp.getWriter(); // 这个打印流，自动 flush
out.println("<html><head><title></title></head><body>hello world !!!</body></html>");
out.flush();
out.close();
/*
* HttpServletRequest req 在这个对象里面封装了客户端到服务器端一切的请求 , 比方说是 客户端的IP是什么，参数什么的。。。
HttpServletResponse resp 服务器端给客户端发的东西，都封装在这，就都能发给客户端啦 */
//}
//
// 有 tomcat 提供这个 doGet 方法，咱们省事多了，要不还得自己实现 socket...
}
<form action=http://127.0.0.1:8888/my/HelloWorldServlet method=post> <!-- /my/HelloWorldServlet method=post> 这样写也可以 -->
<input type=text name=test>
<input type=submit value="提交">
</form>