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我正在使用 Guava 14.0 jar，以下是我的代码

package org.user.module.test;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.concurrent.TimeUnit;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.Cache;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class test
 */
@WebServlet("/test")
public class test extends HttpServlet  {
    private static final long serialVersionUID = 1L;

    Cache<String, Integer> map;

    public test() {
        super();
        // TODO Auto-generated constructor stub
    }

    public void init() throws ServletException
    {
        map=CacheBuilder.newBuilder().
                maximumSize(100).
                expireAfterAccess(10, TimeUnit.MINUTES).
                build();

    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        PrintWriter out=response.getWriter();
        String p=request.getParameter("v");
        Integer a=map.getIfPresent(p);
        if(a==null){
            map.put(p, 1);
            out.println("Putting The Integer:"+a);
        }
        else{
            map.put(p,a++);
            out.println("A is already present and the value is:"+a);
        }

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }

}

错误：

严重：为 servlet org.user.module.test.test java.lang.ClassNotFoundException 分配异常：com.google.common.cache.Cache at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1701) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1546) 在 java.lang.Class.getDeclaredFields0(Native Method) 在 java.lang.Class.privateGetDeclaredFields(Class.java:2317) 在 java.lang。 Class.getDeclaredFields(Class.java:1762) at org.apache.catalina.core.DefaultInstanceManager.populateAnnotationsCache(DefaultInstanceManager.java:276) at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:143) at org .apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:125) 在 org.apache.catalina.core。StandardWrapper.loadServlet(StandardWrapper.java:1136) at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:857) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135) at org .apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) 在 org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 在 org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve .java:168）在 org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 在 org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) 在 org.apache.catalina。 core.StandardEngineValve.invoke(StandardEngineValve.java:118) 在 org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 在 org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579) 在 org.apache.tomcat.util.net 的 org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987) .JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 在java.lang.Thread.run(Thread.java:722)runWorker(ThreadPoolExecutor.java:1145) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 在 java.lang.Thread.run(Thread.java:722)runWorker(ThreadPoolExecutor.java:1145) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 在 java.lang.Thread.run(Thread.java:722)

从这里下载 jar 下载链接 链接到我的项目文件夹（项目名称：test2）链接

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1 回答 1

5

显而易见的答案是；从应用程序服务器指定的类路径中找不到 Google guava jar。jar 应该存在于WEB-INF/classes或WEB-INF/lib中。Apache Tomcat 还从$CATALINA_HOME/lib文件夹加载公共类。

于 2013-09-01T20:11:14.373 回答