Servlet获取Request和Response

分析Request

import java.io.IOException;
import java.util.Enumeration;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Interface
 *      servlet容器（服务器）创建了这个对象,和服务器耦合性高
 * 为了让解析请求信息更加的方便
 *      行
 *      头
 *      网
 *      体       
 */
public class HiServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取请求行信息
        getRequestLine(request);
        //获取请求头信息
        getRequestHeader(request);
        //获取网络信息信息
        getRequestNet(request);
        //获取请求体信息
        getRequestBody(request);
    }

    /**
         * 获取请求行信息
         * @param request
         */
    private void getRequestLine(HttpServletRequest request) {
        System.out.println("请求方式" + request.getMethod());
        System.out.println("资源路径url" + request.getRequestURL());
        System.out.println("资源路径uri" + request.getRequestURI());
        System.out.println("协议" + request.getScheme());
        System.out.println("协议版本" + request.getProtocol());
        System.out.println("项目名称" + request.getContextPath());
    }

    /**
     * 获取请求头信息
     * @param request
     */
    private void getRequestHeader(HttpServletRequest request) {
        //获取指定的请求头信息
        System.out.println("User-Agent:" + request.getHeader("User-Agent"));
        System.out.println("User-Agent:" + request.getHeader("User-Agent".toLowerCase()));//大小写无影响
        System.out.println("User-Agent:" + request.getHeader("User-Agent".toUpperCase()));
        //获取所有的请求头信息
        Enumeration headerNames = request.getHeaderNames();
        //遍历所有的名字
        while (headerNames.hasMoreElements()) {
            //获取请求头的名字
            String headerName = headerNames.nextElement();
            //获取名字对应的值
            System.out.println(headerName + ":" + request.getHeader(headerName));
        }
    }

    /**
     * 获取网络信息
     * @param request
     */
    private void getRequestNet(HttpServletRequest request) {
        System.out.println("服务器信息:" + request.getLocalAddr() + ":" + request.getLocalPort());
        System.out.println("客户端信息:" + request.getRemoteAddr() + ":" + request.getRemotePort());
    }

    /**
     * 获取请求参数
     * @param request
     */
    private void getRequestBody(HttpServletRequest request) {
        //获取请求参数对应的值
        System.out.println("用户名" + request.getParameter("uname"));//text
        System.out.println("密码" + request.getParameter("pwd"));//password
        System.out.println("电子邮箱" + request.getParameter("email"));//text
        System.out.println("年龄" + request.getParameter("age"));//text
        System.out.println("真实姓名" + request.getParameter("realname"));//text
        System.out.println("性别" + request.getParameter("gender"));//radio
        //一对多的时候
        String[] favs = request.getParameterValues("fav");//checkbox
        //判断是否为空
        if (favs != null && favs.length >= 1) {
            //遍历
            for (int i = 0; i < favs.length; i++) {
                System.out.println(favs[i]);
            }
        }
    }
}

分析Response

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 服务器创建了这个对象
 *      行
 *      头
 *      体
 * @author Administrator
 *
 */
public class HiServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("HiServlet.service()");
        //响应行(一般不需要程序员手动操作
        //      resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
        //响应头
        resp.setHeader("Server", "Tomcat");
        //不能设置同名的值，新值会覆盖掉上一个值
        resp.setHeader("hello", "bjsxt");
        resp.setHeader("hello", "sxt");
        //允许多个同名的值
        resp.addHeader("hi", "hanmeimei");
        resp.addHeader("hi", "lilei");
        //设置mime类型(可以解决中文乱码)
        resp.setCharacterEncoding("UTF-8");
        resp.setHeader("content-type", "text/html;charset=utf-8");
        //响应实体内容
        resp.getWriter().print("
hello 汉字  jin liang bu yao chu xian zhong wen" + Math.random() + " 
");
    }
}