java.lang.ClassFormatError：方法中的Absent Code属性在类文件javax / persistence / EntityExistsException中不是native或abstract

Question

我有一个Entity类，我正在尝试使用maven创建一个endpoint-lib。

我的POM文件看起来像这样

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>

    <groupId>test.myweb</groupId>
    <artifactId>mywebtest20151012</artifactId>

    <properties>
        <appengine.app.version>1</appengine.app.version>
        <appengine.target.version>1.9.21</appengine.target.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <!-- Compile/runtime dependencies -->
        <dependency>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-api-1.0-sdk</artifactId>
            <version>${appengine.target.version}</version>
        </dependency>
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!-- Javaee API -->
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>6.0</version>
        </dependency>

        <!-- Test Dependencies -->
        <dependency>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-testing</artifactId>
            <version>${appengine.target.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.google.appengine</groupId>
            <artifactId>appengine-api-stubs</artifactId>
            <version>${appengine.target.version}</version>
            <scope>test</scope>
        </dependency>
        <!-- dependency> <groupId>javax.jdo</groupId> <artifactId>jdo2-api</artifactId> 
            <version>2.3-20090302111651</version> </dependency -->
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <version>2.5.1</version>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <archiveClasses>true</archiveClasses>
                    <webResources>
                        <!-- in order to interpolate version from pom into appengine-web.xml -->
                        <resource>
                            <directory>${basedir}/src/main/webapp/WEB-INF</directory>
                            <filtering>true</filtering>
                            <targetPath>WEB-INF</targetPath>
                        </resource>
                    </webResources>
                </configuration>
            </plugin>

            <plugin>
                <groupId>com.google.appengine</groupId>
                <artifactId>appengine-maven-plugin</artifactId>
                <version>${appengine.target.version}</version>
            </plugin>
        </plugins>
    </build>

</project>

创建端点库时出现以下错误

Caused by: java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/persistence/EntityExistsException
  at java.lang.ClassLoader.defineClass1(Native Method)
  at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
  at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  at java.net.URLClassLoader.defineClass(URLClassLoader.java:455)
  at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
  at java.net.URLClassLoader$1.run(URLClassLoader.java:367)
  at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
  at java.lang.Class.getDeclaredMethods0(Native Method)
  at java.lang.Class.privateGetDeclaredMethods(Class.java:2688)
  at java.lang.Class.getDeclaredMethods(Class.java:1962)
  at com.google.api.server.spi.MethodHierarchyReader.buildServiceMethods(MethodHierarchyReader.java:177)
  at com.google.api.server.spi.MethodHierarchyReader.readMethodHierarchyIfNecessary(MethodHierarchyReader.java:50)
  at com.google.api.server.spi.MethodHierarchyReader.getEndpointOverrides(MethodHierarchyReader.java:131)
  at com.google.api.server.spi.config.annotationreader.ApiConfigAnnotationReader.readEndpointMethods(ApiConfigAnnotationReader.java:279)
  at com.google.api.server.spi.config.annotationreader.ApiConfigAnnotationReader.loadEndpointMethods(ApiConfigAnnotationReader.java:66)
  at com.google.api.server.spi.config.ApiConfigLoader.loadConfiguration(ApiConfigLoader.java:76)
  at com.google.api.server.spi.tools.AnnotationApiConfigGenerator.generateConfig(AnnotationApiConfigGenerator.java:59)
  at com.google.api.server.spi.tools.GenApiConfigAction.genApiConfig(GenApiConfigAction.java:87)
  at com.google.api.server.spi.tools.GetClientLibAction.getClientLib(GetClientLibAction.java:78)
  at com.google.api.server.spi.tools.GetClientLibAction.execute(GetClientLibAction.java:57)
  at com.google.api.server.spi.tools.EndpointsTool.execute(EndpointsTool.java:69)
  at com.google.api.server.spi.tools.EndpointsTool.main(EndpointsTool.java:101)
  at com.google.appengine.endpoints.EndpointsMojo.executeEndpointsCommand(EndpointsMojo.java:112)
  at com.google.appengine.endpoints.EndpointsGetClientLib.execute(EndpointsGetClientLib.java:78)
  at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
  ... 21 more