request获取用户请求信息和数据
package com.lanou;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.Map;
@WebServlet(urlPatterns = "/res")
public class ResServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//request代表请求对象,获取用户提交的信息和数据
//获取请求方法(GET POST)
String method = req.getMethod();
System.out.println(method);
//获取客户端ip地址
String remoteAddr = req.getRemoteAddr();
System.out.println(remoteAddr);
//获取请求协议
String protocol = req.getProtocol();
System.out.println(protocol);
//前端通过请求的参数向后端提交数据
String name = req.getParameter("name");
System.out.println(name);
String age = req.getParameter("age");
System.out.println(Integer.valueOf(age));
//获取多个参数[多选框]
Map<String, String[]> parameterMap = req.getParameterMap();
System.out.println(parameterMap);
for (String key : parameterMap.keySet()) {
System.out.println(key+"\t"+ Arrays.toString(parameterMap.get(key)));
}
}
}
用户请求转发
package com.lanou;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet(urlPatterns = "/dis")
public class DisServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//请求转发
//如果一个servlet处理不完一个请求
//可以把请求对象转发给另一个servlet继续处理
System.out.println("dis收到请求");
//请求转发的地址
req.getRequestDispatcher("/res").forward(req,resp);
req.getRequestDispatcher("/Hello.html").forward(req,resp);
System.out.println("完成");
}
}