JSP屬性范圍，通過以下幾個測試代碼來學習request屬性的范圍
測試一(JSP動態指令方式傳參)：
測試內容：
<jsp:param .../>添加參數,通過<jsp:forward page="...">來實現服務器端跳轉,以此來測試request屬性的范圍：
頁面RequestScopeDemo.jsp (添加info1參數) —> 通過<jsp:forward page="RequestScopeDemo_1.jsp">跳轉
↓
頁面RequestScopeDemo_1.jsp (添加info2參數) —> 通過<jsp:forward page="RequestScopeDemo_2.jsp">跳轉
↓
頁面RequestScopeDemo_2.jsp (request對象中取到了info1、info2兩個參數的值)
CODE:
RequestScopeDemo.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - Page 1</title></head>
<body><h1>跳轉前的頁面：page 1</h1><%//想輸入一個字符串“<jsp:param ... >”不能直接輸出必須通過轉義輸出String info1="page 1 頁面中添加（<jsp:param ... />）的參數 !";request.setCharacterEncoding("utf-8");%><jsp:forward page="RequestScopeDemo_1.jsp"><jsp:param name="info1" value="<%=info1%>" /></jsp:forward>
</body>
</html>RequestScopeDemo1.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - page2</title></head>
<body><h1>跳轉中頁面：page 2</h1><%String info2="page 2 頁面中添加（<jsp:param ... />）的參數 !"; %>info參數：<%=request.getParameter("info2")%><br/><jsp:forward page="RequestScopeDemo_2.jsp"><jsp:param name="info2" value="<%=info2%>" /></jsp:forward>
</body>
</html>RequestScopeDemo2.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - page3</title></head>
<body><h1>跳轉到的頁面：page 3</h1><%/*request對象的源頭設置了編碼，所以這里就不需要設置啦*///request.setCharacterEncoding("utf-8"); %><h2>Page1頁面中傳遞過來的info1參數：<%=request.getParameter("info1")%></h2><br/><h2>Page2頁面中傳遞過來的info2參數：<%=request.getParameter("info2")%></h2><br/><h2>request.getCharacterEncoding()的值：<%=request.getCharacterEncoding()%></h2>
</body>
</html>測試結果：
測試二（request.setAttribute()封裝屬性方式傳參）：
測試內容：
request.setAttribute()方法封裝參數，通過<jsp:forward page="...">來實現服務器端跳轉，以此來測試request屬性的范圍：
頁面RequestScopeDemo_t.jsp (添加info1參數) —> 通過<jsp:forward page="RequestScopeDemo_t1.jsp">跳轉
↓
頁面RequestScopeDemo_t1.jsp (添加info2參數) —> 通過<jsp:forward page="RequestScopeDemo_t2.jsp">跳轉
↓
頁面RequestScopeDemo_t1.jsp (request對象中取到了info1、info2兩個參數的值)
CODE:
RequestScopeDemo_t.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - Page 1</title></head>
<body><h1>跳轉前的頁面：page 1</h1><%request.setCharacterEncoding("utf-8");request.setAttribute("info1","Page1中添加（setAttribute）的參數");%><jsp:forward page="RequestScopeDemo_t1.jsp" />
</body>
</html>RequestScopeDemo_t1.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - page2</title></head>
<body><h1>跳轉中頁面：page 2</h1><%request.setAttribute("info2","Page2中添加（setAttribute）的參數");%>跳轉中的頁面，info1參數：<%=request.getAttribute("info1")%><br/><jsp:forward page="RequestScopeDemo_t2.jsp" />
</body>
</html>RequestScopeDemo_t2.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - page3</title></head>
<body><h1>跳轉到的頁面：page 3</h1><h2>第一個頁面，info1參數：<%=request.getAttribute("info1")%></h2><br/><h2>第二個頁面，info2參數：<%=request.getAttribute("info2")%></h2><br/><h2>request.getCharacterEncoding()的值：<%=request.getCharacterEncoding()%></h2>
</body>
</html>測試結果：
測試三（URL地址方式傳參）：
測試內容：
URL地址方式添加參數，通過超鏈接<a href=".." ..>來實現服客戶端跳轉，以此來測試request屬性的范圍：
頁面RequestScopeDemo_1.jsp 頁中通過<a href="RequestScopeDemo_2.jsp?info1=Page1頁面的參數">鏈接到下一個頁面</a>跳轉
↓
頁面RequestScopeDemo_2.jsp 頁中通過<a href="RequestScopeDemo_3.jsp?info2=Page1頁面的參數">鏈接到下一個頁面</a>跳轉
↓
頁面RequestScopeDemo_2.jsp(request對象中取到了info2的參數值)
CODE:
RequestScopeDemo_1.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Qequest屬性范圍 - Page 1</title></head>
<body><h1>跳轉前的頁面：page 1</h1><%request.setCharacterEncoding("utf-8");%><a href="RequestScopeDemo_2.jsp?info1=Page1頁面的參數">鏈接到下一個頁面</a>
</body>
</html>RequestScopeDemo_2.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - page2</title></head>
<body><h1>跳轉中頁面：page 2</h1><%request.setAttribute("info2","Page2中的參數");%>跳轉中的頁面，info1參數：<%=request.getParameter("info1")%><br/><a href="RequestScopeDemo_3.jsp?info2=Page2頁面的參數">鏈接到下一個頁面</a>
</body>
</html>RequestScopeDemo_3.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head><title>Request屬性范圍 - page3</title></head>
<body><h1>跳轉到的頁面：page 3</h1><h2>第一個頁面，info1參數：<%=request.getParameter("info1")%></h2><br/><h2>第二個頁面，info2參數：<%=request.getParameter("info2")%></h2><br/><h2>request.getCharacterEncoding()的值：<%=request.getCharacterEncoding()%></h2>
</body>
</html>測試結果：
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