JSP导入JSONObject有时会出现错误

Question

我正在将jsp文件中的JSONObject导入，但是编译器会不时出现错误

SEVERE: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: [15] in the generated java file: [C:\eclipse\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\shop-app\org\apache\jsp\shop_jsp.java]
Only a type can be imported. org.json.JSONObject resolves to a package

Stacktrace:
    at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
    at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:198)
    at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:450)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:361)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:336)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:323)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:570)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:356)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
    at servlet.ShopsServlet.doGet(ShopsServlet.java:63)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

märts 30, 2015 11:05:34 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [shop] in context with path [/shop-app] threw exception [Unable to compile class for JSP: 

An error occurred at line: [15] in the generated java file: [C:\eclipse\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\shop-app\org\apache\jsp\shop_jsp.java]
Only a type can be imported. org.json.JSONObject resolves to a package

Stacktrace:] with root cause
org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: [15] in the generated java file: [C:\eclipse\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\shop-app\org\apache\jsp\shop_jsp.java]
Only a type can be imported. org.json.JSONObject resolves to a package

Stacktrace:
    at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
    at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:198)
    at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:450)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:361)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:336)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:323)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:570)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:356)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
    at servlet.ShopsServlet.doGet(ShopsServlet.java:63)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

使用以下行导入JSONObject类：

<%@ page import="org.json.JSONObject" %>

这里可能是什么问题？我什至没有在我的JSP中使用JSONObject，所以错误在导入中。

Answer 1

我检查了pom.xml中的依赖关系，然后重新启动了服务器。问题已经解决了。解决。

Answer 2

通过将json库放入Web项目的LIB文件夹中，可以消除此错误。该错误表明您在页面中导入的“ org.json.JSONObject”以及相关的jar文件在您的项目中不可用，因此请将JAR文件放入LIB并重新启动服务器。