GWT编译后的数据核增强器error=7

Question

我正在使用Maven和Eclipse Photon构建一个GWT + App Engine + JDO项目(当我从命令行构建项目时，也会出现同样的错误)。编译阶段结束后，Datanucleus通知我这个错误：

Failed to execute goal org.datanucleus:maven-datanucleus-plugin:3.2.0-m1:enhance (default) on project gwtAppEngineJDOProjectName: Error while executing the DataNucleus tool 'org.datanucleus.enhancer.DataNucleusEnhancer'. Error while executing process. Cannot run program "/bin/sh": error=7

在我的项目结构中有一个src/main/resources的META-INF/jdoconfig.xml。在war插件执行之后，META-INF/jdoconfig.xml已经正确地存储在/target/WARFOLDER/MET-INF/文件夹中。

我实际的jdo-conf：

  <?xml version="1.0" encoding="utf-8" standalone="no"?>
<jdoconfig xmlns="http://java.sun.com/xml/ns/jdo/jdoconfig" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/jdo/jdoconfig http://java.sun.com/xml/ns/jdo/jdoconfig_3_0.xsd">
  <persistence-manager-factory name="transactions-optional">
      <property name="javax.jdo.PersistenceManagerFactoryClass" value="org.datanucleus.api.jdo.JDOPersistenceManagerFactory"/>
      <property name="javax.jdo.option.ConnectionURL" value="appengine"/>
      <property name="datanucleus.cache.level2.mode" value="none"/>
      <property name="javax.jdo.option.NontransactionalRead" value="true"/>
      <property name="javax.jdo.option.NontransactionalWrite" value="true"/>
      <property name="javax.jdo.option.RetainValues" value="true"/>
      <property name="datanucleus.appengine.autoCreateDatastoreTxns" value="true"/>
      <property name="datanucleus.appengine.singletonPMFForName" value="true"/>
  </persistence-manager-factory>
</jdoconfig>

我的pom.xml中的自动增强过程

 <plugin>
    <groupId>org.datanucleus</groupId>
    <artifactId>maven-datanucleus-plugin</artifactId>
    <version>3.2.0-m1</version>
    <configuration>
        <api>JDO</api>
        <props>${basedir}/datanucleus.properties</props>
        <verbose>true</verbose>
        <enhancerName>ASM</enhancerName>
    </configuration>
    <executions>
        <execution>
            <phase>process-classes</phase>
            <goals>
                <goal>enhance</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-core</artifactId>
            <version>3.1.3</version>
        </dependency>
    </dependencies>
</plugin>

如何解决error=7 Datanucleus错误？谢谢。

Answer 1

将datanucleus-maven-plugin与以下配置一起使用：

 <plugin>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-maven-plugin</artifactId>
        <version>5.0.2</version>
        <configuration>
            <fork>false</fork>
            <log4jConfiguration>${basedir}/log4j.properties</log4jConfiguration>
            <verbose>true</verbose>
        </configuration>
        <executions>
            <execution>
                <phase>process-classes</phase>
                <goals>
                    <goal>enhance</goal>
                </goals>
            </execution>
        </executions>
    </plugin>

增强过程会在编译阶段后自动运行。fork参数已设置为false，以防止出现“参数列表太长”的消息。参见http://www.datanucleus.org/products/accessplatform/jdo/enhancer.html#maven。