Question

所以我制作一个小型网络应用程序来获取有关游戏的信息，我已经制作了一个搜索到API的搜索栏，然后我获得了与搜索名称最相似的前10个游戏。但我只显示标题。

游戏有很多属性，其中一个是ID，它允许我使用控制器获取游戏的所有信息。

现在应用程序的工作方式如下：
1：你搜索游戏的标题
2.一个控制器给我一个ID列表和id，我得到关于游戏的其余信息，但我只显示标题。

现在，我想做什么：
3.当你点击一个标题时，你使用一个控制器，并从它请求的ID（再次，我不确定我是否可以使用以前的游戏对象）所有来自该游戏的信息并显示它。

控制器工作正常，但我遇到了HTML问题。

这是搜索的控制器：

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

    String query = request.getParameter("searchQuery");
    RequestDispatcher rd = null;  

    log.log(Level.FINE, "Searching for games that contain " + query);
    GameResource game = new GameResource();
    GameSearch[] gameResults = null;
    gameResults = game.getGameSearch(query);

    //System.out.println(Arrays.toString(gameResults));
    List<Game> listaBusqueda = new ArrayList<Game>();

    if (gameResults.length!=0){
        rd = request.getRequestDispatcher("/success.jsp");
        for (GameSearch g : gameResults) {
            listaBusqueda.add(game.getGame(g.getId().toString()));
        }
        request.setAttribute("games", listaBusqueda);
    } else {
        log.log(Level.SEVERE, "Game object: " + gameResults);
        rd = request.getRequestDispatcher("/error.jsp");
    }
    rd.forward(request, response);

}

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

这是使用ID

给我一个游戏的控制器

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

    String gameId = request.getParameter("id");
    GameResource resource = new GameResource();
    RequestDispatcher rd = null;
    log.log(Level.FINE, "Retrieving game");

    Game game = resource.getGame(gameId);

    if(game!=null) {
        rd = request.getRequestDispatcher("/success.jsp");
        request.setAttribute("Game", game);
        request.setAttribute("Item", "gameID");
    } else {
        log.log(Level.SEVERE, "Cannot retrieve game: ");
        rd = request.getRequestDispatcher("/error.jsp");
        rd.forward(request, response);
    }
}

/**
 * @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);
  }

}

它们都有效，在最后一个中正确创建了对象并获得了ID。

现在，这是success.jsp的html，这就是问题所在：

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<link rel="stylesheet" type="text/css" href="style.css">
<title>Search results</title>
</head>
<body>


<fieldset id="IGDB">
    <legend>
        IGDB search for
        <c:out value="${param.searchQuery}" />
    </legend>

    <c:forEach items="${requestScope.games}" var="game">
        <article name="gameArticle" id="gameArticle"></article>
        <a href="GameIdController?id=${game.id}"><c:out value="${game.name}" 
/></a>

        <br />
    </c:forEach>
</fieldset>

<c:if test="${requestScope.Item=='gameID' }">
<c:forEach items="${requestScope.Game}" var="game">
        <article name="gameArticle" id="gameArticle"></article>
        <c:out value="${game.name}" />

        <br />
    </c:forEach>
    $game = ${requestScope.Game}
    <c:out value="${game.name}"/>

</c:if>

<article name = "gameByIDArticle" id = "gameByIDArticle">

</article>

</body>
</html>

当我点击标题时，我会被重定向到一个空白网页（http://localhost:8090/GameIdController?id=IdOfTheGame),as，您可以看到该ID包含在网址中，但它完全空白，应该再次包含标题，如我所述代码。

我还将包含我的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:web="http://java.sun.com/xml/ns/javaee" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <servlet>
    <description></description>
    <display-name>GameSearchController</display-name>
    <servlet-name>GameSearchController</servlet-name>
    <servlet-class>aiss.controller.GameSearchController</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>GameSearchController</servlet-name>
    <url-pattern>/GameSearchController</url-pattern>
  </servlet-mapping>
  <servlet>
    <description></description>
    <display-name>GamePopularityController</display-name>
    <servlet-name>GamePopularityController</servlet-name>
    <servlet-class>aiss.controller.GamePopularityController</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>GamePopularityController</servlet-name>
    <url-pattern>/GamePopularityController</url-pattern>
  </servlet-mapping>
  <context-param>
    <param-name>resteasy.servlet.mapping.prefix</param-name>
    <param-value>/api</param-value>
  </context-param>
  <servlet>
    <servlet-name>Resteasy</servlet-name>
    <servlet- 


 class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
</servlet- 
class>
    <init-param>
      <param-name>javax.ws.rs.Application</param-name>
      <param-value>aiss.api.GameApplication</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>Resteasy</servlet-name>
    <url-pattern>/api/*</url-pattern>
  </servlet-mapping>
  <error-page>
    <exception-type>java.lang.Throwable</exception-type>
    <location>/error.jsp</location>
  </error-page>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>GameIdController</display-name>
    <servlet-name>GameIdController</servlet-name>
    <servlet-class>aiss.controller.GameIdController</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>GameIdController</servlet-name>
    <url-pattern>/GameIdController</url-pattern>
  </servlet-mapping>
 </web-app>

Answer 1

好吧，我想我明白为什么你会看到一个空白页面。一切都按预期工作，问题似乎与此有关：

if(game!=null) {
    rd = request.getRequestDispatcher("/success.jsp");
    request.setAttribute("Game", game);
    request.setAttribute("Item", "gameID");
} else {
    log.log(Level.SEVERE, "Cannot retrieve game: ");
    rd = request.getRequestDispatcher("/error.jsp");
    rd.forward(request, response);
}

您看到空白页面的原因是您的游戏变量不为空。并且你在if if阻止的第一部分中没有前向声明。

if(game!=null) {
    rd = request.getRequestDispatcher("/success.jsp");
    request.setAttribute("Game", game);
    request.setAttribute("Item", "gameID");
    rd.forward(request, response); // missing this!
} else {
    log.log(Level.SEVERE, "Cannot retrieve game: ");
    rd = request.getRequestDispatcher("/error.jsp");
    rd.forward(request, response);
}

编辑：为了回应评论中的其他问题，我认为forEach因此存在问题：

<c:forEach items="${requestScope.Game}" var="game">

将其更改为：

<c:forEach items="${Game}" var="game">

使用MVC单击html中的文本时获取有关对象的更多信息

1 个答案: