6 常用request、response方法

1. 什么是request、response

2. request

2.1 代码

1. 获取url信息
2. 获取参数信息
3. 获取请求头部信息

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.Map;
import java.util.Set;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RegisterServlet extends HttpServlet {
    @Override
    public void init(ServletConfig config) throws ServletException {
        // TODO Auto-generated method stub
        super.init(config);
        System.out.println("RegisterServlet加载完成");
    }
    protected void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException{
        System.out.println("=====URL信息======");
        System.out.println("浏览器发出请求时的完整URL，包括协议 主机名 端口(如果有): " + request.getRequestURL());
        System.out.println("浏览器发出请求的资源名部分，去掉了协议和主机名: " + request.getRequestURI());
        System.out.println("请求行中的参数部分: " + request.getQueryString());
        System.out.println("浏览器所处于的客户机的IP地址: " + request.getRemoteAddr());
        System.out.println("浏览器所处于的客户机的主机名: " + request.getRemoteHost());
        System.out.println("浏览器所处于的客户机使用的网络端口: " + request.getRemotePort());
        System.out.println("服务器的IP地址: " + request.getLocalAddr());
        System.out.println("服务器的主机名: " + request.getLocalName());
        System.out.println("得到客户机请求方式: " + request.getMethod());
        System.out.println("=====参数信息======");
        //获取简单的参数信息
        System.out.println("获取单值参数name:" + request.getParameter("name"));
        //获取多值参数信息
        String[] hobits = request.getParameterValues("hobits");
        System.out.println("获取具有多值的参数hobits: " + Arrays.asList(hobits));
        //获取参数键值对映射
        System.out.println("通过 getParameterMap 遍历所有的参数： ");
        Map<String, String[]> parameters = request.getParameterMap();
        Set<String> paramNames = parameters.keySet();
        for (String param : paramNames) {
            String[] value = parameters.get(param);
            System.out.println(param + ":" + Arrays.asList(value));
        }
        System.out.println("=====请求头信息======");
        Enumeration<String> headerNames= request.getHeaderNames();
        while(headerNames.hasMoreElements()){
            String header = headerNames.nextElement();
            String value = request.getHeader(header);
            System.out.printf("%s\t%s%n",header,value);
        }
        String html = "<div style='color:red'>成功</div>";
        response.setContentType("text/html; charset=UTF-8");
        PrintWriter pw = response.getWriter();
    }
}

2.2 效果

3 response

https://how2j.cn/k/servlet/servlet-response/556.html#step1610