亲爱的专业人员，我正在尝试在jsp页面（Netbeans，Spring项目）中显示mysql表中的数据。为此，我创建了模型类：
public class Impression {
private int id;
private String username;
private String text;
public static List<Impression> listAllImpressions() throws SQLException, ClassNotFoundException {
List<Impression> listImpression = new ArrayList<>();
Class.forName("com.mysql.jdbc.Driver");
try (java.sql.Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/guestbook", "root", "");) {
Statement st = conn.createStatement();
st.executeQuery("SELECT impression_id, username, text FROM impression");
ResultSet rs = st.getResultSet();
while (rs.next()) {
int id = rs.getInt("impression_id");
String username = rs.getString("username");
String text = rs.getString("text");
Impression impression = new Impression(id, "aaa", text);
listImpression.add(impression);
}
}
return listImpression;
}
}
然后创建一个控制器：
@Controller
public class ImpressionController {
@RequestMapping(value = "/newjsp", method = RequestMethod.GET)
public String allImpressions(@ModelAttribute("impressions") Impression impression, ModelMap model) throws ClassNotFoundException, SQLException {
Impression impressions = new Impression();
List<Impression> listImpressions = Impression.listAllImpressions();
return "newjsp";
}
当我尝试在jsp页面（newjsp）中显示数据时，我什么也没得到：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<body>
<center>
<h1>List of user impressions</h1>
</center>
<div align="center">
<table border="1" cellpadding="3">
<tr>
<th>ID</th>
<th>Username</th>
<th>Text</th>
</tr>
<c:forEach var="impressions" items="${listAllImpressions}">
<tr>
<td><c:out value="${impressions.id}" /></td>
<td><c:out value="${impressions.username}" /></td>
<td><c:out value="${impressions.text}" /></td>
</tr>
</c:forEach>
</table>
</div>
</body>
</html>
我是Java Spring MVC的新手。任何帮助将不胜感激。 :)
最佳答案
您可能应该首先验证列表中是否确实包含项目。