HTTP狀態500 - 處理程序處理失敗;嵌套的異常是java.lang.NoClassDefFoundError：

Question

我想將外部jar文件集成到我的項目中。 （mambu的模型 - V3.8.10.jar）

但我收到這樣的錯誤信息：

HTTP Status 500 - Handler processing failed; nested exception is java.lang.NoClassDefFoundError: com/mambu/loans/shared/model/LoanAccount  


org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.NoClassDefFoundError: com/mambu/loans/shared/model/LoanAccount 
org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletionWithError(DispatcherServlet.java:1287) 
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:961) 
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877) 
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966) 
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:620) 
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:727) 
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)  

根源：

java.lang.ClassNotFoundException: com.mambu.loans.shared.model.LoanAccount 
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720) 
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571) 
java.lang.Class.getDeclaredMethods0(Native Method) 
java.lang.Class.privateGetDeclaredMethods(Class.java:2688) 
java.lang.Class.getDeclaredMethods(Class.java:1962) 
com.google.inject.spi.InjectionPoint.getInjectionPoints(InjectionPoint.java:662) 
com.google.inject.spi.InjectionPoint.forInstanceMethodsAndFields(InjectionPoint.java:356) 
com.google.inject.internal.ConstructorBindingImpl.getInternalDependencies(ConstructorBindingImpl.java:151) 
com.google.inject.internal.InjectorImpl.getInternalDependencies(InjectorImpl.java:585) 
com.google.inject.internal.InjectorImpl.cleanup(InjectorImpl.java:543) 
com.google.inject.internal.InjectorImpl.initializeJitBinding(InjectorImpl.java:529) 
com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:847) 
com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:772) 
com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:256) 
com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:205) 
com.google.inject.internal.InjectorImpl.getInternalFactory(InjectorImpl.java:853) 
com.google.inject.internal.InjectorImpl.getProviderOrThrow(InjectorImpl.java:967) 
com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1000) 
com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:961) 
com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1013) 
com.mambu.apisdk.MambuAPIFactory.getLoanService(MambuAPIFactory.java:86) 
comm.app.starter.HomeController.Opaaaaana(HomeController.java:167) 
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
java.lang.reflect.Method.invoke(Method.java:483) 
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) 
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) 
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) 
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:781) 
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:721) 
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) 
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943) 
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877) 
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966) 
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:620) 
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:727) 
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)  

這裏是我的POM XML：

HTTP ：//maven.apache.org/maven-v4_0_0.xsd「> 4.0.0 com.springapp kapiv2 war 1.0快照 KAPI

<properties> 
    <spring.version>4.1.1.RELEASE</spring.version> 
</properties> 

<dependencies> 
    <dependency> 
     <groupId>com.mambu</groupId> 
     <artifactId>mambumodels</artifactId> 
     <version>3.8.10</version> 
     <scope>system</scope> 
     <systemPath>${project.basedir}/lib/mambu-models-V3.8.10.jar 
     </systemPath> 
     <optional>false</optional> 
    </dependency> 
    <!-- <dependency> 
     <groupId>com.cenqua.clover</groupId> 
     <artifactId>clover</artifactId> 
     <version>3.0.2</version> 
    </dependency>--> 

    <dependency> 
     <groupId>org.apache.httpcomponents</groupId> 
     <artifactId>httpclient</artifactId> 
     <version>4.2.1</version> 
     <optional>false</optional> 
    </dependency> 
    <dependency> 
     <groupId>com.google.code.gson</groupId> 
     <artifactId>gson</artifactId> 
     <version>1.7.1</version> 
     <scope>compile</scope> 
     <optional>false</optional> 
    </dependency> 
    <dependency> 
     <groupId>org.apache.commons</groupId> 
     <artifactId>commons-io</artifactId> 
     <version>1.3.2</version> 
     <optional>false</optional> 
    </dependency> 
    <dependency> 
     <groupId>javax.jdo</groupId> 
     <artifactId>jdo-api</artifactId> 
     <version>3.0</version> 
    </dependency> 
    <dependency> 
     <groupId>com.google.inject</groupId> 
     <artifactId>guice</artifactId> 
     <version>3.0</version> 
     <optional>false</optional> 
    </dependency> 
    <dependency> 
     <groupId>org.mockito</groupId> 
     <artifactId>mockito-all</artifactId> 
     <version>1.8.5</version> 
     <optional>false</optional> 
    </dependency> 
    <dependency> 
     <groupId>junit</groupId> 
     <artifactId>junit</artifactId> 
     <version>4.8.1</version> 
     <scope>test</scope> 
    </dependency> 
    <dependency> 
     <groupId>com.google.gwt</groupId> 
     <artifactId>gwt-dev</artifactId> 
     <version>2.7.0</version> 
    </dependency> 
    <!-- <dependency> 
     <groupId>com.google.gwt</groupId> 
     <artifactId>gwt-user</artifactId> 
     <version>1.5.3</version> 
    </dependency>--> 
    <dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-core</artifactId> 
     <version>${spring.version}</version> 
    </dependency> 

    <dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-web</artifactId> 
     <version>${spring.version}</version> 
    </dependency> 

    <dependency> 
     <groupId>javax.servlet</groupId> 
     <artifactId>servlet-api</artifactId> 
     <version>2.5</version> 
    </dependency> 

    <dependency> 
     <groupId>javax.servlet.jsp</groupId> 
     <artifactId>jsp-api</artifactId> 
     <version>2.1</version> 
     <scope>provided</scope> 
    </dependency> 

    <dependency> 
     <groupId>com.fasterxml.jackson.core</groupId> 
     <artifactId>jackson-databind</artifactId> 
     <version>2.2.1</version> 
    </dependency> 

    <dependency> 
     <groupId>javax.mail</groupId> 
     <artifactId>mail</artifactId> 
     <version>1.4.5</version> 
    </dependency> 

    <dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-webmvc</artifactId> 
     <version>${spring.version}</version> 
    </dependency> 

    <dependency> 
     <groupId>org.springframework</groupId> 
     <artifactId>spring-test</artifactId> 
     <version>${spring.version}</version> 
     <scope>test</scope> 
    </dependency> 

    <dependency> 
     <groupId>junit</groupId> 
     <artifactId>junit</artifactId> 
     <version>4.11</version> 
     <scope>test</scope> 
    </dependency> 
</dependencies> 

<build> 
    <finalName>kapi</finalName> 
    <plugins> 
     <plugin> 
      <artifactId>maven-compiler-plugin</artifactId> 
      <configuration> 
       <source>1.8</source> 
       <target>1.8</target> 
      </configuration> 
     </plugin> 

    </plugins> 
</build> 

如果你搜索的NoClassDefFoundError有很多在谷歌搜索結果的 - 但他們都不hellped我。

請問您爲什麼會收到此類錯誤？ 謝謝

Answer 1

的問題是，需要爲運行此功能在運行時是缺少jar文件。所以我把這加到MAVEN

  <plugin> 
      <groupId>org.apache.maven.plugins</groupId> 
      <artifactId>maven-dependency-plugin</artifactId> 
      <executions> 
       <execution> 
        <id>copy-dependencies</id> 
        <phase>prepare-package</phase> 
        <goals> 
         <goal>copy-dependencies</goal> 
        </goals> 
        <configuration> 
         <outputDirectory>${project.build.directory}/myTESTapplication/WEB-INF/lib</outputDirectory> 
         <overWriteReleases>false</overWriteReleases> 
         <overWriteSnapshots>false</overWriteSnapshots> 
         <overWriteIfNewer>true</overWriteIfNewer> 
        </configuration> 
       </execution> 
      </executions> 
     </plugin> 

Answer 2

您在系統範圍中添加依賴項。這意味着，當你編寫應用程序時，你的ide將很好地作爲依賴關係存在，但是在運行代碼時，服務器應該在classpath或lib文件夾下找到依賴項才能正確運行。在這個範圍內，maven和tomcat不會爲你做任何詭計。

http://tomcat.apache.org/tomcat-6.0-doc/class-loader-howto.html是有關類路徑的tomcat引用，當使用系統範圍時，它建議您的webapp下的jar位置使用WEB-INF/lib。如果你想使用maven爲你提供類，你應該使用編譯目標，並有一個回購爲你提供的jar。更多在java.lang.NoClassDefFoundError: in eclipse maven。

Answer 3

問題可能不是該類缺失 - 它可能存在，但未能正確初始化。例如靜態代碼塊中發生異常。

這個答案解釋得很好Why am I getting a NoClassDefFoundError in Java?