HTTP Status 500 - Handler processing failed; nested exception is java.lang.NoClassDefFoundError:

Question

我正在尝试将外部 jar 文件集成到我的项目中。 (mambu-models-V3.8.10.jar)

但是我收到这样的错误信息：

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)

根本原因：

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)

这是我的 POM xml:

http://maven.apache.org/maven-v4_0_0.xsd"> 4.0.0 com.springapp 卡皮夫2 war 1.0-快照卡皮

<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>

如果您搜索 NoClassDefFoundError，google 中有很多结果 - 但其中 none 对我不利。

你能告诉我为什么会收到这样的错误吗？谢谢

Answer 1

您在系统范围内添加依赖项。这意味着，当您编写应用程序代码时，您的 ide 会将它很好地作为依赖项存在，但是当运行编码代码时，服务器应该在类路径或某个 lib 文件夹下找到它之前找到依赖项运行正确。在此范围内，maven 和 tomcat 不会代表您做任何技巧。

http://tomcat.apache.org/tomcat-6.0-doc/class-loader-howto.html is tomcat reference about classpath and it suggests WEB-INF/lib for the jar location under your webapp, when system scope is used. If you do want use the maven to provide the class for you, you should use compile target and have a repo for providing the jar for you. More at java.lang.NoClassDefFoundError: in eclipse maven .

Answer 2

问题可能不是缺少 class - 它可能存在，但未能正确初始化。例如静态代码块出现异常。

这个答案解释得很好Why am I getting a NoClassDefFoundError in Java?

Answer 3

问题是运行启用此功能所需的 jar 文件在运行时间内丢失了。所以我把这个添加到 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 4

在我的例子中，我设置了一个 static final String 抛出异常并导致这个错误，硬编码这个值解决了这个问题：

private static final String SERVICE_NAME = ManifestProvider.getServiceName();

HTTP Status 500 - Handler processing failed; nested exception is java.lang.NoClassDefFoundError:

HTTP Status 500 - Handler processing failed; nested exception is java.lang.NoClassDefFoundError:

java

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