Request對(duì)象如何獲取請(qǐng)求頭數(shù)據(jù)

更新時(shí)間：2024年07月08日 11:07:38 作者：xuebanub1

這篇文章主要介紹了Request對(duì)象如何獲取請(qǐng)求頭數(shù)據(jù)問題,具有很好的參考價(jià)值,希望對(duì)大家有所幫助,如有錯(cuò)誤或未考慮完全的地方,望不吝賜教

Request對(duì)象獲取請(qǐng)求頭數(shù)據(jù)

getHeaderNames()

作用：獲取所有請(qǐng)求頭的名字
返回值類型：Enumeration< String>
Enumeration：是個(gè)迭代器，有兩個(gè)方法 hasMoreElements(); nextElement();

getHeader(String name) （重點(diǎn)）

作用：根據(jù)請(qǐng)求頭的名字，獲取其value值
參數(shù)name即為請(qǐng)求頭的名字
返回值類型：String

測(cè)試代碼

@WebServlet(name = "RequestDemo2", value = "/requestDemo2")
public class RequestDemo2 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //獲取所有請(qǐng)求頭的名稱
        Enumeration<String> headerNames = request.getHeaderNames();
        //遍歷
        while (headerNames.hasMoreElements()){
            String name = headerNames.nextElement();
            //根據(jù)請(qǐng)求頭的名稱獲取請(qǐng)求頭的值
            String value = request.getHeader(name);
            System.out.println(name+":"+value);
        }

    }
}

結(jié)果：

host:localhost
connection:keep-alive
cache-control:max-age=0
sec-ch-ua:"Google Chrome";v="111", "Not(A:Brand";v="8", "Chromium";v="111"
sec-ch-ua-mobile:?0
sec-ch-ua-platform:"Windows"
upgrade-insecure-requests:1
user-agent:Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36
accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
sec-fetch-site:cross-site
sec-fetch-mode:navigate
sec-fetch-user:?1
sec-fetch-dest:document
accept-encoding:gzip, deflate, br
accept-language:zh-CN,zh;q=0.9
cookie:JSESSIONID=BACA32C62CC73505DD0178E34531D21C; _ga=GA1.1.1717905582.1633016465; JSESSIONID=E576986031221D734A3D7882557C867A

使用Request對(duì)象獲取表單的信息

通過request對(duì)象可以獲取表單中的輸入信息，并將這些信息存入到指定的字符串中去

例如有下面一個(gè)表單

<form action="responseUserLogin.jsp" method="post">
    輸入右面的認(rèn)證碼：<input type="text" name="verifyCodeDigit"/><br/>
    用戶類型：<select name="type_User_Admin">
    <option value="1">前臺(tái)用戶</option>
    <option value="2">后臺(tái)管理員</option>
      </select><br/>
    您的名稱：<input type="text" name="userName"/><br/>
    您的密碼：<input type="password" name="userPassword"/><br/>
    <input type="submit" value="提交" name="submitButton"/>
    <input type="reset" value="取消" />
 </form>

<body>
  <%! String verifyCodeDigit; %>
  <%! String type_User_Admin; %>
  <%! String userName; %>
  <%! String userPassword; %>
    <% request.setCharacterEncoding("UTF-8");
verifyCodeDigit = request.getParameter("paperTitle"); 
     if(request.getParameter("type_User_Admin").equals("1")) {
    type_User_Admin = "前臺(tái)用戶";
    }else{
            type_User_Admin = "后臺(tái)管理員";
    }
    
      userName = request.getParameter("userName");
      userPassword = request.getParameter("userPassword");
     %>
 </body>