Question

 $ java -version java version "1.6.0_45" Java(TM) SE Runtime
 Environment (build 1.6.0_45-b06-451-10M4406) Java HotSpot(TM) 64-Bit
 Server VM (build 20.45-b01-451, mixed mode)

Tomcat版本：7.0.40

我在这里关注开始的servlet / jsp教程：

https://stackoverflow.com/tags/servlets/info

我收到此错误：

HTTP状态500 - 绝对uri： http://java.sun.com/jsp/jstl/functions无法解决 web.xml或使用此应用程序部署的jar文件

看起来它来自以这行开头的.jsp文件：

<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>

<!DOCTYPE html>
<html lang="en">

我像这样编译了我的servlet：

~/java_programs/modernServlet$ javac -cp /Library/Tomcat/lib/servlet-api.jar -d classes src/com/example/controller/HelloServlet.java

然后我将该文件复制到Tomcat目录中WEB-INF类下的相同目录结构中。我应该在classpath中包含一些其他jar文件吗？

====

好的，我下载并将jstl jar复制到Tomcat的lib目录，现在我得到了各种编译错误：

$ javac -cp "/Library/Tomcat/lib/servlet-api.jar;/Library/Tomcat/lib/jstl-1.2.jar" -d classes src/com/example/controller/HelloServlet.java
src/com/example/controller/HelloServlet.java:7: package javax.servlet does not exist
import javax.servlet.ServletException;
                    ^
src/com/example/controller/HelloServlet.java:8: package javax.servlet.annotation does not exist
import javax.servlet.annotation.WebServlet;
                               ^
src/com/example/controller/HelloServlet.java:9: package javax.servlet.http does not exist
import javax.servlet.http.HttpServlet;
                         ^
src/com/example/controller/HelloServlet.java:10: package javax.servlet.http does not exist
import javax.servlet.http.HttpServletRequest;
                         ^
src/com/example/controller/HelloServlet.java:11: package javax.servlet.http does not exist
import javax.servlet.http.HttpServletResponse;
                         ^
src/com/example/controller/HelloServlet.java:14: cannot find symbol
symbol: class HttpServlet
public class HelloServlet extends HttpServlet {
                                  ^
src/com/example/controller/HelloServlet.java:13: cannot find symbol
symbol: class WebServlet
@WebServlet("/hello")
 ^
src/com/example/controller/HelloServlet.java:17: cannot find symbol
symbol  : class HttpServletRequest
location: class com.example.controller.HelloServlet
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                         ^
src/com/example/controller/HelloServlet.java:17: cannot find symbol
symbol  : class HttpServletResponse
location: class com.example.controller.HelloServlet
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                                                     ^
src/com/example/controller/HelloServlet.java:17: cannot find symbol
symbol  : class ServletException
location: class com.example.controller.HelloServlet
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                                                                                          ^
src/com/example/controller/HelloServlet.java:23: cannot find symbol
symbol  : class HttpServletRequest
location: class com.example.controller.HelloServlet
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                          ^
src/com/example/controller/HelloServlet.java:23: cannot find symbol
symbol  : class HttpServletResponse
location: class com.example.controller.HelloServlet
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                                                      ^
src/com/example/controller/HelloServlet.java:23: cannot find symbol
symbol  : class ServletException
location: class com.example.controller.HelloServlet
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                                                                                           ^
src/com/example/controller/HelloServlet.java:16: method does not override or implement a method from a supertype
    @Override
    ^
src/com/example/controller/HelloServlet.java:22: method does not override or implement a method from a supertype
    @Override
    ^
15 errors

Answer 1

这不是编译错误。这是运行时错误。

您只需按照JSTL tag wiki page（以及间接JSP tag wiki page）的说明将JSTL放入/WEB-INF/lib。

您无需在编译时类路径中指定它。它是运行时错误，而不是编译错误。你成功编译了servlet，对吗？

尝试使用类路径中的JSTL进行编译时出现编译错误是因为您在使用基于Unix的操作系统时在类路径中使用特定于Windows的路径分隔符;，这需要{{1} }作为路径分隔符。但毕竟，在编译时类路径中不需要JSTL。

Answer 2

您需要将JSTL jar添加到Tomcat lib文件夹中。

您可以在此处下载：http://mvnrepository.com/artifact/javax.servlet/jstl/1.2

单击“下载”按钮，然后将该文件复制到Tomcat的lib文件夹中。

新错误意味着类路径中缺少servlet-api.jar。

堆栈溢出servlet教程错误

2 个答案: