Grails，app-engine，jpa - 初学者在使用grails时遇到问题

时间：2010-04-24 09:19:10

标签： google-app-engine grails jpa

我正在尝试通过以下几个教程来了解使用Google App Engine和JPA的Grails：

我有grails 1.3.0 RC 2和App Engine SDK 1.3.3，我正在使用Windows 7.我尝试的步骤是：

  1. grails create-app appname
  2. cd appname
  3. grails install-plugin app-engine。当被问及jdo / jpa时，我回答jpa。它似乎是自动安装gorm-jpa插件，虽然教程都建议手动安装gorm-jpa。
  4. grails install-plugin gorm-jpa（以防万一）
  5. grails create-domain-class test.Person

  6. 编辑grails-app/domain/test/Person.groovy以添加姓名和地址字段：

    package test
import javax.persistence.*;

// import com.google.appengine.api.datastore.Key;
@Entity
class Person implements Serializable {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  Long id

  @Basic
  String name

  @Basic
  String address

  static constraints = {
    id visible:false
  }
}

  7. grails generate-all test.Person

    8. 我在最后一步中遇到错误：

    C:\Users\John\Workspaces\STS\appname>grails generate-all test.Person
Welcome to Grails 1.3.0.RC2 - http://grails.org/
Licensed under Apache Standard License 2.0
Grails home is set to: C:\Users\John\Downloads\grails-1.3.0.RC2\grails-1.3.0.RC2

Base Directory: C:\Users\John\Workspaces\STS\appname
Resolving dependencies...
Dependencies resolved in 493ms.
Running script C:\Users\John\Downloads\grails-1.3.0.RC2\grails-1.3.0.RC2\scripts\GenerateAll.groovy
Environment set to development
     [copy] Copied 4 empty directories to 2 empty directories under C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources
     [copy] Copied 4 empty directories to 2 empty directories under C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources
     [copy] Copied 1 empty directory to 1 empty directory under C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources
    [mkdir] Created dir: C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes
  [groovyc] Compiling 12 source files to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes
Note: C:\Users\John\.grails\1.3.0.RC2\projects\appname\plugins\gorm-jpa-0.7.1\src\java\org\grails\jpa\domain\JpaGrailsDomainClass.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
  [groovyc] Compiling 8 source files to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes
    [mkdir] Created dir: C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources\grails-app\i18n
[native2ascii] Converting 13 files from C:\Users\John\Workspaces\STS\appname\grails-app\i18n to C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources\grails-app\i18n
    [mkdir] Created dir: C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources\plugins\gorm-jpa-0.7.1\grails-app\i18n
    [mkdir] Created dir: C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources\plugins\app-engine-0.8.10\grails-app\i18n
[native2ascii] Converting 1 file from C:\Users\John\.grails\1.3.0.RC2\projects\appname\plugins\gorm-jpa-0.7.1\grails-app\i18n to C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources\plugins\gorm
-jpa-0.7.1\grails-app\i18n
[native2ascii] Converting 1 file from C:\Users\John\.grails\1.3.0.RC2\projects\appname\plugins\app-engine-0.8.10\grails-app\i18n to C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources\plugins\a
pp-engine-0.8.10\grails-app\i18n
     [copy] Copying 1 file to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes
     [copy] Copying 2 files to C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources
     [copy] Copied 2 empty directories to 2 empty directories under C:\Users\John\.grails\1.3.0.RC2\projects\appname\resources
     [copy] Copying 1 file to C:\Users\John\.grails\1.3.0.RC2\projects\appname
    [mkdir] Created dir: C:\Users\John\Workspaces\STS\appname\web-app\plugins\app-engine-0.8.10
     [copy] Copying 1 file to C:\Users\John\Workspaces\STS\appname\web-app\plugins\app-engine-0.8.10
     [copy] Copying 1 file to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF
    [mkdir] Created dir: C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\lib
     [copy] Copying 64 files to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\lib
Configuring persistence for AppEngine
    [mkdir] Created dir: C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes\META-INF
     [copy] Copying 1 file to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes\META-INF
    [mkdir] Created dir: C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\plugins\app-engine-0.8.10
     [copy] Copying 2 files to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\plugins\app-engine-0.8.10
    [mkdir] Created dir: C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\plugins\gorm-jpa-0.7.1
     [copy] Copying 2 files to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\plugins\gorm-jpa-0.7.1
Packaging AppEngine jar files
Enhancing JDO classes
  [enhance] DataNucleus Enhancer (version 1.1.4) : Enhancement of classes
  [enhance] DataNucleus Enhancer completed with success for 1 classes. Timings : input=589 ms, enhance=200 ms, total=789 ms. Consult the log for full details
  [groovyc] Compiling 1 source file to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF\classes
     [copy] Copying 1 file to C:\Users\John\.grails\1.3.0.RC2\projects\appname
     [copy] Copying 1 file to C:\Users\John\Workspaces\STS\appname\web-app\WEB-INF
Configuring persistence for AppEngine
Packaging AppEngine jar files
Enhancing JDO classes
  [enhance] DataNucleus Enhancer (version 1.1.4) : Enhancement of classes
  [enhance] DataNucleus Enhancer completed with success for 1 classes. Timings : input=585 ms, enhance=28 ms, total=613 ms. Consult the log for full details
Generating views for domain class test.Person ...
java.lang.reflect.InvocationTargetException
        at SimpleTemplateScript1.run(SimpleTemplateScript1.groovy:43)
        at _GrailsGenerate_groovy.generateForDomainClass(_GrailsGenerate_groovy:85)
        at _GrailsGenerate_groovy$_run_closure1.doCall(_GrailsGenerate_groovy:50)
        at GenerateAll$_run_closure1.doCall(GenerateAll.groovy:42)
        at gant.Gant$_dispatch_closure5.doCall(Gant.groovy:381)
        at gant.Gant$_dispatch_closure7.doCall(Gant.groovy:415)
        at gant.Gant$_dispatch_closure7.doCall(Gant.groovy)
        at gant.Gant.withBuildListeners(Gant.groovy:427)
        at gant.Gant.this$2$withBuildListeners(Gant.groovy)
        at gant.Gant$this$2$withBuildListeners.callCurrent(Unknown Source)
        at gant.Gant.dispatch(Gant.groovy:415)
        at gant.Gant.this$2$dispatch(Gant.groovy)
        at gant.Gant.invokeMethod(Gant.groovy)
        at gant.Gant.executeTargets(Gant.groovy:590)
        at gant.Gant.executeTargets(Gant.groovy:589)
Caused by: java.lang.NoClassDefFoundError: org/hibernate/MappingException
        ... 15 more
Caused by: java.lang.ClassNotFoundException: org.hibernate.MappingException
        at org.codehaus.groovy.tools.RootLoader.findClass(RootLoader.java:156)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at org.codehaus.groovy.tools.RootLoader.loadClass(RootLoader.java:128)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        ... 15 more
Error running generate-all: null

    我做错了什么？

    我应该咨询哪些日志文件以获取详细信息？

1 个答案:

答案 0 :(得分：1)

似乎使用标准脚手架将可见性设置为false会导致错误。我不得不从这个块中删除中间行，它起作用了：

 static constraints = {
   id visible:false
 }

我认为这是'约定优于配置'的成本之一：隐藏的依赖关系。或者可能是我还在学习......

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