JSP 中的 HTTP 状态 500 并使用 JSONObject

Question

我正在使用 Intellij IDEA 14 ULTIMATE 创建 Web 应用程序。我想使用 html 显示和 jsp 连接 java 和 html 显示之间的数据。
所以我使用 JSONObject，在导入 json-lib-2.4-jdk15.jar
之后使用 request/response 的方法，导入 javax.servlet.jsp-api （来自 maven）
tomcat jar 由项目自动生成。

我删除任何一个，都会出现编译错误。 i 运行 tomcat, 浏览器显示:

HTTP Status 500 - java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/servlet/getArticle_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/apache/jasper/runtime/InstanceManagerFactory, have different Class objects for the type he.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager; used in the signature

type Exception report

message java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/servlet/getArticle_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/apache/jasper/runtime/InstanceManagerFactory, have different Class objects for the type he.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager; used in the signature

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/servlet/getArticle_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/apache/jasper/runtime/InstanceManagerFactory, have different Class objects for the type he.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager; used in the signature
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:348)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/servlet/getArticle_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/apache/jasper/runtime/InstanceManagerFactory, have different Class objects for the type he.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager; used in the signature
    org.apache.jsp.servlet.getArticle_jsp._jspInit(getArticle_jsp.java:34)
    org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
    org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:376)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.64 logs.

Tomcat 本地主机日志：

 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [jsp] in context with path [] threw exception [java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/servlet/getArticle_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/apache/jasper/runtime/InstanceManagerFactory, have different Class objects for the type he.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager; used in the signature] with root cause
java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager;" the class loader (instance of org/apache/jasper/servlet/JasperLoader) of the current class, org/apache/jsp/servlet/getArticle_jsp, and the class loader (instance of org/apache/catalina/loader/StandardClassLoader) for resolved class, org/apache/jasper/runtime/InstanceManagerFactory, have different Class objects for the type he.jasper.runtime.InstanceManagerFactory.getInstanceManager(Ljavax/servlet/ServletConfig;)Lorg/apache/tomcat/InstanceManager; used in the signature
    at org.apache.jsp.servlet.getArticle_jsp._jspInit(getArticle_jsp.java:34)
    at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:49)
    at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:180)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:376)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

编辑：

jar import, module, Library, lib package, lib package in out 和 Artifacts 搞得一头雾水

Answer 1

确保您生成的 war 中没有这些 jars 中的一些： Servlet-api.jar 或 javax-servlet-api.jar 或 jsp-api.jar 或 javax-servlet-jsp.jar

运行

mvn clean package

再次测试

Answer 2

这个问题主要是jar冲突引起的，你应该：

不要从maven import servlet-api和jsp-api，jar包太多，和你自己的不完全一致tomcat api.
从您的本地文件夹导入这两个 jar（就这些就足够了），您项目中的 tomcat 主文件夹 Moudles->Dependencies
import json jar pack，我推荐三个：
①json-lib（net.sf.json）
②org.json
③json-simple
2 & 3 是轻量级的，可以直接导入到 Moudles->Dependencies AND 复制它们到你的 web->WEB-INF->lib
如果选择第一个，则必须导入 commons-beanutils commons-collections commons-lang commons-logging ezmorph 进一步。更好地在同一版本包中使用它们:)

JSP 中的 HTTP 状态 500 并使用 JSONObject

HTTP state 500 in JSP and use JSONObject

jsp

tomcat

artifacts

jar

intellij-idea

编辑：