05---RequeseDemo基础代码

package cn.itcast.web.request;

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;

/**
* 演示Request对象获取请求行数据
*/

@WebServlet("/requestDemo1")
public class RequestDemo1 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

}

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        /*
            1. 获取请求方式：GET
                * String getMethod()
            2. (*)获取虚拟目录：/day14
                * String getContextPath()
            3. 获取Servlet路径: /requestDemo1
                * String getServletPath()
            4. 获取get方式请求参数：name=zhangsan
                * String getQueryString()
            5. (*)获取请求URI：/day14/demo1
                * String getRequestURI():  /day14/requestDemo1
                * StringBuffer getRequestURL() :http://localhost/day14/requestDemo1
            6. 获取协议及版本：HTTP/1.1
                * String getProtocol()

7. 获取客户机的IP地址：
* String getRemoteAddr()

         */
        //1. 获取请求方式：GET
        String method = request.getMethod();
        System.out.println(method);
        //2.(*)获取虚拟目录：/day14
        String contextPath = request.getContextPath();
        System.out.println(contextPath);
        //3. 获取Servlet路径: /demo1
        String servletPath = request.getServletPath();
        System.out.println(servletPath);
        //4. 获取get方式请求参数：name=zhangsan
        String queryString = request.getQueryString();
        System.out.println(queryString);
        //5.(*)获取请求URI：/day14/demo1
        String requestURI = request.getRequestURI();
        StringBuffer requestURL = request.getRequestURL();
        System.out.println(requestURI);
        System.out.println(requestURL);
        //6. 获取协议及版本：HTTP/1.1
        String protocol = request.getProtocol();
        System.out.println(protocol);
        //7. 获取客户机的IP地址：
        String remoteAddr = request.getRemoteAddr();
        System.out.println(remoteAddr);
    }
}

package cn.itcast.web.request;

@WebServlet("/requestDemo2")
public class RequestDemo2 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

}

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //演示获取请求头数据

        //1.获取所有请求头名称
        Enumeration<String> headerNames = request.getHeaderNames();
        //2.遍历
        while(headerNames.hasMoreElements()){
            String name = headerNames.nextElement();
            //根据名称获取请求头的值
            String value = request.getHeader(name);
            System.out.println(name+"---"+value);
        }

}
}

@WebServlet("/requestDemo3")
public class RequestDemo3 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//演示获取请求头数据:user-agent

        String agent = request.getHeader("user-agent");
        //判断agent的浏览器版本
        if(agent.contains("Chrome")){
            //谷歌
            System.out.println("谷歌来了...");
        }else if(agent.contains("Firefox")){
            //火狐
            System.out.println("火狐来了...");
        }

}
}

@WebServlet("/requestDemo4")
public class RequestDemo4 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//演示获取请求头数据:referer

String referer = request.getHeader("referer");
System.out.println(referer);//http://localhost/day14/login.html

        //防盗链
        if(referer != null ){
            if(referer.contains("/day14")){
                //正常访问
               // System.out.println("播放电影....");
                response.setContentType("text/html;charset=utf-8");
                response.getWriter().write("播放电影....");
            }else{
                //盗链
                //System.out.println("想看电影吗？来优酷吧...");
                response.setContentType("text/html;charset=utf-8");
                response.getWriter().write("想看电影吗？来优酷吧...");
            }
        }

}
}

@WebServlet("/requestDemo5")
public class RequestDemo5 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取请求消息体--请求参数

        //1.获取字符流
        BufferedReader br = request.getReader();
        //2.读取数据
        String line = null;
        while((line = br.readLine()) != null){
            System.out.println(line);
        }

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
}

@WebServlet("/requestDemo6")
public class RequestDemo6 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//post 获取请求参数

        //根据参数名称获取参数值
        String username = request.getParameter("username");
       /* System.out.println("post");
        System.out.println(username);*/

       //根据参数名称获取参数值的数组
        String[] hobbies = request.getParameterValues("hobby");
        /*for (String hobby : hobbies) {
            System.out.println(hobby);
        }*/

//获取所有请求的参数名称

        Enumeration<String> parameterNames = request.getParameterNames();
        /*while(parameterNames.hasMoreElements()){
            String name = parameterNames.nextElement();
            System.out.println(name);
            String value = request.getParameter(name);
            System.out.println(value);
            System.out.println("----------------");
        }*/

        // 获取所有参数的map集合
        Map<String, String[]> parameterMap = request.getParameterMap();
        //遍历
        Set<String> keyset = parameterMap.keySet();
        for (String name : keyset) {

            //获取键获取值
            String[] values = parameterMap.get(name);
            System.out.println(name);
            for (String value : values) {
                System.out.println(value);
            }

System.out.println("-----------------");
}

}

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //get 获取请求参数
/*
        //根据参数名称获取参数值
        String username = request.getParameter("username");
        System.out.println("get");
        System.out.println(username);*/