java.lang.ClassNotFoundException 和 Tomcat WAR 文件

Question

我正在尝试为我目前正在进行的项目制作一个简单的 REST API 以简化我每天必须完成的任务，以及当我到达托管它的地方时我遇到了 500 服务器错误。查看（tomcat 主目录）/logs/localhost.2021-10-22.log 中的日志，我发现了这个错误：

22-Oct-2021 21:33:58.974 SEVERE [http-nio-13760-exec-64] org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [OrderServlet]
java.lang.ClassNotFoundException: api.OrderServlet
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1407)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1215)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:538)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:519)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:149)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1070)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:788)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:128)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1722)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

我这里还有“不存在”的 class 的代码：

package api;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONObject;

import data.Order;

public class OrderServlet extends HttpServlet {
    
    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
        
        String requestUrl = request.getRequestURI();
        String id = requestUrl.substring("cafe/orders/".length());
        
        
        Order order = Requests.getInstance().getOrder(id);
        
        if (order != null) {
            String json = "{\n";
            json += "\"id\": " + JSONObject.quote(order.getID()) + ",\n";
            json += "\"id\": " + JSONObject.quote(order.getName()) + ",\n";
            json += "\"id\": " + JSONObject.quote(String.valueOf(order.getTime())) + ",\n";
            //various parameters removed to prevent abuse in the future (I'm looking at you, Dax)
            //I'd rather not have a coffee order show up with a comically large amount of creamers in it
            json += "};";
            response.getOutputStream().println(json);
        } else {
            //order was not found
            response.sendError(404);
        }
    }
    
    @Override
    public void doPost(HttpServletRequest request, HttpServletResponse responce) throws IOException, ServletException {
        String id = request.getParameter("id");
        String name = request.getParameter("name");
        int time = Integer.parseInt(request.getParameter("time"));
        //various parameters removed
        
        Requests.getInstance().putOrder(new Order(id, name, time, type, //various parameters removed
));
    }

}

我检查过 class 确实存在，我尝试重建 classes，导入为非编译文件并弄乱 web.xml，然后我检查构建路径中是否没有随机 jre6 库（来自 here）。我没有使用 Maven，Tomcat 能够很好地加载文档和管理器。如何让 class 被 Tomcat 识别？

Answer 1

看起来文件没有从 Eclipse 正确导出，因此手动解决了这个问题。

编辑：原来问题是我的源文件夹不是 Eclipse 试图导出的文件夹。进入 Properties > Deployment assembly 并更改源文件夹修复它（感谢@Piotr P Karwasz！）

java.lang.ClassNotFoundException 和 Tomcat WAR 文件

java.lang.ClassNotFoundException with Tomcat WAR file

java

rest

tomcat