【发布时间】：2015-12-09 14:31:00
【问题描述】：
我正在为过去 6 个月参加的 Web 开发课程构建动态网页。目前我有一个动态网络项目，我需要在我建立的引导网站上动态更改数据库内容。我必须使用 JSP、AJAX 和 Java Servlet 来完成这项工作。
我遇到的问题似乎是服务器端的。该网站用于发布和阅读笑话，当我尝试在按下按钮 (id="getRandom") 时将随机笑话发布到数据库中的一个页面时，似乎什么也没发生。
这是我目前的代码：
JSP：
<%@ 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 lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Vicoteka | Random</title>
<!-- Bootstrap -->
<link href="css/bootstrap.css" rel="stylesheet">
<link rel="stylesheet" href="css/stil.css">
<!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
<!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
<!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]-->
</head>
<body>
<nav class="navbar navbar-inverse navbar-fixed-top">
<div class="container">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#defaultNavbar1"><span class="sr-only">Toggle navigation</span><span class="icon-bar"></span><span class="icon-bar"></span><span class="icon-bar"></span></button>
<a class="navbar-brand" href="#"><img src="img/brand.png" alt="Vicoteka Logo"></a> </div>
<!-- Collect the nav links -->
<div class="collapse navbar-collapse" id="defaultNavbar1">
<ul class="nav navbar-nav pull-right">
<li ><a href="index.jsp">Pocetna<span class="sr-only">(current)</span></a></li>
<li class="active"><a href="random.jsp">Random Vic<span class="sr-only">(current)</span></a></li>
<li ><a href="vicevi.jsp">Vicevi<span class="sr-only">(current)</span></a></li>
<li> <a href="kategorije.jsp" >Kategorije<span class="sr-only">(current)</span></a>
</li>
<li ><a href="myModal" type="button" data-toggle="modal" data-target="#myModal" id="dugme">Dodaj<span class="sr-only">(current)</span></a></li>
</ul>
<!-- /.navbar-collapse -->
</div>
<!-- /.container-->
</div>
</nav>
<section id="random">
<div class="container">
<div class="jumbotron">
<h2>Blic Vic</h2>
<div class="problem_text">
<div class="vic">
<span class="lead" id="message">Procitejte svoj random vic</span>
</div>
<hr>
<p>
<input class="btn btn-warning btn-xl pull-right" id="getRandom" type="submit" value="random"role="button"/>
</p>
</div>
</div>
</div>
</section>
<c:out value="${vic.text}"></c:out>
<footer class="navbar navbar-fixed-bottom">
<div class="row spacer" >
<div class="text-center col-md-6 col-md-offset-3">
<p>Copyright © 2015 VICOTEKA - Developed by Dijana Markovic</p>
</div>
</div>
</footer>
<!-- Dodaj Vic Prozor (Modal) -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
<h4 class="modal-title" id="myModalLabel">Dadajte Vas Vic</h4>
</div>
<div class="modal-body">
<div class="jumbotron">
<div class="container">
<div class="message">
</div>
<form method="post" action="ControllerServlet">
<input type="hidden" name="action" value="addNew"/>
<div class="form-group">
<label for="title">Title</label>
<input type="text" class="form-control" name="title">
</div>
<div class="form-group">
<label for="author">Autor</label>
<input type="text" class="form-control" name="author">
</div>
<div class="form-group row">
<div class="container">
<label for="Kategorija">Kategorija</label>
<select class="form-control" name="category">
<option value="mujo_haso">Mujo i Haso</option>
<option value="plavuse">Plavuse</option>
<option value="panduri">Panduri</option>
<option value="maliPerica">Mali Perica</option>
</select>
</div>
</div>
<div class="form-group">
<label for="name">Vas Vic</label>
<textarea class="form-control" required data-validation-required-message="Niste ukucali vic!" name="text"></textarea>
</div>
</form>
</div>
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Odkazi</button>
<button type="submit" class="btn btn-warning">Sacuvaj</button>
</div>
</div>
</div>
</div>
<!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
<script src="js/jquery-1.11.2.min.js"></script>
<script src="js/ajax.js"></script>
<!-- Include all compiled plugins (below), or include individual files as needed -->
<script src="js/bootstrap.js"></script>
</body>
</html>
Java Srevlet： 包控制器；
import java.io.IOException;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.mysql.jdbc.Connection;
import dao.Vic;
import service.VicMetode;
/**
* Servlet implementation class ControllerServlet
*/
@WebServlet("/ControllerServlet")
public class ControllerServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final String USERNAME = "root";
private static final String PASSWORD = "root";
private static final String CONN_STRING = "jdbc:mysql://localhost:3306/vicevi";
private Connection conn = null;
/**
* @see Servlet#init(ServletConfig)
*/
public void init(ServletConfig config){
try {
Class.forName("com.mysql.jdbc.Driver");
//connect to the database
conn = (Connection) DriverManager.getConnection(CONN_STRING, USERNAME, PASSWORD);
System.out.println("CONECTED");
} catch (SQLException e) {
System.err.println(e);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ServletContext context = ((ServletConfig) request).getServletContext();
context.setAttribute("conn", conn);
String action = request.getParameter("action");
System.out.println(action);
if(action.equals("addNew")){
String title = request.getParameter("title");
String author = request.getParameter("author");
String category = request.getParameter("category");
String text = request.getParameter("text");
VicMetode vicService = new VicMetode(conn);
String message = vicService.addVic(title, author, category, text);
request.setAttribute("message", message);
request.getRequestDispatcher("index.jsp").forward(request, response);
}
if(action.equals("loadFirstPage")){
VicMetode vicService = new VicMetode(conn);
List<Vic> vicList = vicService.getVicList();
request.getSession().setAttribute("vicList", vicList);
}
if(action.equals("random")){
VicMetode vicService = new VicMetode(conn);
List<Vic> vicList = vicService.getVicList();
int index = (int)(Math.random() * vicList.size() - 1);
request.getSession().setAttribute("vic", vicList.get(index));
}
}
}
AJAX：
$(document).ready(function() {
$('#getRandom').bind( 'click',function() {
var action = $('#message').val();
$.ajax({
type : 'POST',
data : {
action : action
},
url : 'ControllerServlet',
}).success(function(response) {
$('#message').load('random.jsp');
});
});
});
这是我在使用 Tomcat 运行浏览器控制台时遇到的日志错误： Screen Shot
一个星期以来，我一直在努力寻找解决方案，这让我发疯。任何帮助，将不胜感激。提前致谢。
【问题讨论】：
-
该错误显然在您的控制器中。 500 错误意味着服务器代码中存在错误。
-
单独测试你的控制器代码。转到localhost:8080/Vicko/ControllerServlet。它应该在浏览器中完整打印错误消息。与我们分享该错误消息。
-
这是我运行控制器时得到的prntscr.com/9c5qvk
-
在您的 tomcat 文件夹中，您会看到一个名为 logs 的文件夹。错误日志在那里。它被称为 stacktrace.log 或 catalina.out。看看你是否可以在这里分享这些日志文件。
-
我无法找到该日志文件，这是我从 Tomcat 获得的：我具体在哪里可以找到日志文件。 prntscr.com/9c73k6
标签： java jquery ajax jsp servlets