org.apache.jasper.JasperException： Unable to compile class for JSP：

jsp java tomcat

2022-09-02 10:51:37

嗨，我正在尝试用tomcat编译一个简单的jsp文件，但我一直有这个错误消息

org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: 13 in the jsp file: /WebContent/test.jsp
Member cannot be resolved to a type
10: <body>
11: <%  
12:     //MyBatisDao myDao = new MyBatisDao();
13:     List<Member> list; // = myDao.func("test");
14:     //out.println("Result list= " + list);
15: %>
16: </body>

test.jsp （at Webcontent）

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="pageNumber.*, java.util.*, java.io.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html> 
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%  
    List<Member> list;
%>
</body>
</html>

会员.java

package pageNumber;
public class Member {
 private String id;
 private String pw;
 private int point;
 private int lvl;

 public Member() {}
 public Member(String id, String pw, int point, int lvl) {
  this.id = id;
  this.pw = pw;
  this.point = point;
  this.lvl = lvl;
 }

 public String getId() { return id; }
 public void setId(String id) { this.id = id; }
 public String getPw() { return pw; }
 public void setPw(String pw) { this.pw = pw; }
 public int getPoint() { return point; }
 public void setPoint(int point) { this.point = point; }     
 public int getLvl() { return lvl; }
 public void setLvl(int lvl) { this.lvl = lvl; }
 public String toString() {
  return "ID= " + id + ", PW= " + pw + ", POINT= " + point + ", LVL= " + lvl;
 }

}

据我所知，我遇到了这个问题，因为我的tomcat找不到类文件，所以我把我的类文件放在

build/classes/pageNumber（其中 pageNumber 是我的包名）
WEB-INF/classes/pageNumber
tomcat\work\Catalina\localhost_\org\apache\jsp\pageNumber

但都没有成功。有什么帮助吗？

编辑：在我更改导入声明后

<%@ page import="pageNumber.*, java.util.*, java.io.*" %>

自

<%@ page import="java.util.List, pageNumber.Member" %>

它实际上给了我一种新型的错误：

org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: 15 in the generated java file
Only a type can be imported. pageNumber.Member resolves to a package

An error occurred at line: 12 in the jsp file: /WebContent/test.jsp
Member cannot be resolved to a type
9: </head>
10: <body>
11: <%  
12:     List<Member> list; // = myDao.func("test");
13: %>
14: </body>
15: </html>

答案 1

这可能是由罐子冲突引起的。删除 servlet-api.jar 在 servlet/WEB-INF/ 目录中，%Tomcat home%/lib 已经有这个库了。

答案 2

导致此问题的原因是您需要在 JSP 中导入该类。确保还包括其他包和类，如。pageNumber.Memberjava.util.List

<%@ page import="pageNumber.*, java.util.*" %>

不过，在 JSP 中使用脚本小工具还是遇到了一个主要问题。请参阅如何避免 JSP 文件中的 Java 代码？并开始练习 EL 和 JSTL，并更多地关注 MVC 解决方案。