6-3 编程题

来源：6-3 自由编程

JakePrim

2020-01-13 17:03:37

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/request-struc/work/test" method="get">
<input type="text" name="key">
<input type="submit" value="查询">
</form>
</body>
</html>

请求的servlet如下: 需要注意重定向和请求转发的路径问题

@WebServlet("/work/test")
public class WorkTestServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	private HashMap<String, String> map;

	/**
	 * @see HttpServlet#HttpServlet()
	 */
	public WorkTestServlet() {
		super();
		map = new HashMap<String, String>();
		map.put("apple", "苹果");
		map.put("mac", "苹果笔记本电脑");
		map.put("window", "Windows电脑");
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
	 *      response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String key = request.getParameter("key");// 获取请求参数
		if (map.containsKey(key)) {
			request.setAttribute("key", map.get(key));
			//请求转发的方式
			System.out.println(map.get(key));
            request.getRequestDispatcher("/success.jsp").forward(request, response);//请求转发不需要 context-path
		} else {
			HttpSession session = request.getSession();
			session.setAttribute("msg", "没有找到对应的单词解释");
			response.sendRedirect("/request-struc/error.jsp");//注意重定向需要 context-path
		}
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
	 *      response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

success.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
  <% String value = (String)request.getAttribute("key"); %>
  <h1 style="color: blue;"><%=value %></h1>
</body>
</html>

error.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<% String msg = (String)session.getAttribute("msg"); %>
<h1 style="color: red;"><%=msg %></h1>
</body>
</html>

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