JSP内置对象request获取请求头和请求参数实战

╰半橙微兮° 2021-07-24 20:15 494阅读 0赞

**一 实战1**

1 form.jsp

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
    <!DOCtype html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title> 收集参数的表单页 </title>
        <meta name="website" content="http://www.crazyit.org" />
    </head>
    <body>
    <form id="form1" action="request1.jsp" method="post">
    用户名：<br/>
    <input type="text" name="name"><hr/>
    性别：<br/>
    男：<input type="radio" name="gender" value="男">
    女：<input type="radio" name="gender" value="女"><hr/>
    喜欢的颜色：<br/>
    红：<input type="checkbox" name="color" value="红">
    绿：<input type="checkbox" name="color" value="绿">
    蓝：<input type="checkbox" name="color" value="蓝"><hr/>
    来自的国家：<br/>
    <select name="country">
        <option value="中国">中国</option>
        <option value="美国">美国</option>
        <option value="俄罗斯">俄罗斯</option>
    </select><hr/>
    <input type="submit" value="提交">
    <input type="reset" value="重置">
    </form>
    </body>
    </html>

2 request1.jsp

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
    <%@ page import="java.util.*" %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title> 获取请求头/请求参数 </title>
        <meta name="website" content="http://www.crazyit.org" />
    </head>
    <body>
    <%
    // 获取所有请求头的名称
    Enumeration<String> headerNames = request.getHeaderNames();
    while(headerNames.hasMoreElements())
    {
        String headerName = headerNames.nextElement();
        // 获取每个请求、及其对应的值
        out.println(
            headerName + "-->" + request.getHeader(headerName) + "<br/>");
    }
    out.println("<hr/>");
    // 设置解码方式，对于简体中文，使用GBK解码
    request.setCharacterEncoding("GBK");   // ①
    // 下面依次获取表单域的值
    String name = request.getParameter("name");
    String gender = request.getParameter("gender");
    // 如果某个请求参数有多个值，将使用该方法获取多个值
    String[] color = request.getParameterValues("color");
    String national = request.getParameter("country");
    %>
    
    您的名字：<%=name%><hr/>
    您的性别：<%=gender%><hr/>
    
    您喜欢的颜色：<%for(String c : color)
    {out.println(c + " ");}%><hr/>
    您来自的国家：<%=national%><hr/>
    </body>
    </html>

3 测试

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 1][]

**二 实战2**

1 代码

2 测试

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 2][]

**三 实战3**

1 代码

<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title> 获取包含非西欧字符的GET请求参数 </title>
        <meta name="website" content="http://www.crazyit.org" />
    </head>
    <body>
    <%
    // 获取请求里包含的查询字符串
    String rawQueryStr = request.getQueryString();
    out.println("原始查询字符串为：" + rawQueryStr + "<hr/>");
    // 使用URLDecoder解码字符串
    String queryStr = java.net.URLDecoder.decode(
        rawQueryStr , "UTF-8");
    out.println("解码后的查询字符串为：" + queryStr + "<hr/>");
    // 以&符号分解查询字符串
    String[] paramPairs = queryStr.split("&");
    for(String paramPair : paramPairs)
    {
        out.println("每个请求参数名、值对为：" + paramPair + "<br/>");
        // 以=来分解请求参数名和值
        String[] nameValue = paramPair.split("=");
        out.println(nameValue[0] + "参数的值是：" +
            nameValue[1]+ "<hr/>");
    }
    %>
    </body>
    </html>

2 测试

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 3][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70]: /images/20210724/31a47191a0b04d0cae4acd6260aa2647.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 1]: /images/20210724/4617854d3958491e81dcf7af42fe29df.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 2]: /images/20210724/5ad22275591e4610a7f9659f0a763b79.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 3]: /images/20210724/2967955c0d2a4bf08779891b9055eb28.png