spring-data - Liquibase:无法解析持久性单元根 URL

Question

我正在尝试将 Liquibase 与 jHipster 应用程序一起使用，但遇到了一些问题。

pom 中的相关部分是:

<plugin>
                <groupId>org.liquibase</groupId>
                <artifactId>liquibase-maven-plugin</artifactId>
                <version>${liquibase.version}</version>
                <dependencies>
                    <dependency>
                        <groupId>org.javassist</groupId>
                        <artifactId>javassist</artifactId>
                        <version>3.18.2-GA</version>
                    </dependency>
                    <dependency>
                        <groupId>org.liquibase.ext</groupId>
                        <artifactId>liquibase-hibernate4</artifactId>
                        <version>${liquibase-hibernate4.version}</version>
                    </dependency>
                    <dependency>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-starter-data-jpa</artifactId>
                        <version>${project.parent.version}</version>
                    </dependency>
                    <dependency>
                        <groupId>org.hibernate</groupId>
                        <artifactId>hibernate-core</artifactId>
                        <version>4.3.11.Final</version>
                    </dependency>
                    <dependency>
                        <groupId>javax</groupId>
                        <artifactId>javaee-web-api</artifactId>
                        <version>6.0</version>
                    </dependency>


                </dependencies>
                <configuration>
                    <changeLogFile>src/main/resources/config/liquibase/master.xml</changeLogFile>
                    <diffChangeLogFile>
                        src/main/resources/config/liquibase/changelog/${maven.build.timestamp}_changelog.xml
                    </diffChangeLogFile>
                    <driver>org.postgresql.Driver</driver>
                    <url>jdbc:postgresql://localhost:5432/myapp</url>
                    <defaultSchemaName/>
                    <username>postgres</username>
                    <password/>
                    <referenceUrl>hibernate:spring:com.myapp.domain?dialect=org.hibernate.dialect.PostgreSQL94Dialect&amp;hibernate.ejb.naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringNamingStrategy</referenceUrl>
                    <verbose>true</verbose>
                    <logging>debug</logging>
                </configuration>
            </plugin>

我得到的错误是:

INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.844 s
[INFO] Finished at: 2016-07-03T00:20:52+02:00
[INFO] Final Memory: 25M/386M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.liquibase:liquibase-maven-plugin:3.4.2:diff (default-cli) on project staffservice: Error setting up or running Liquibase: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL: class path resource [] cannot be resolved to URL because it does not exist -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.liquibase:liquibase-maven-plugin:3.4.2:diff (default-cli) on project staffservice: Error setting up or running Liquibase: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:216)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: Error setting up or running Liquibase: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
    at org.liquibase.maven.plugins.AbstractLiquibaseMojo.execute(AbstractLiquibaseMojo.java:398)
    at org.liquibase.maven.plugins.LiquibaseDatabaseDiff.execute(LiquibaseDatabaseDiff.java:146)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
    ... 20 more
Caused by: liquibase.exception.DatabaseException: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
    at liquibase.integration.commandline.CommandLineUtils.createDatabaseObject(CommandLineUtils.java:157)
    at org.liquibase.maven.plugins.LiquibaseDatabaseDiff.performLiquibaseTask(LiquibaseDatabaseDiff.java:166)
    at org.liquibase.maven.plugins.AbstractLiquibaseMojo.execute(AbstractLiquibaseMojo.java:394)
    ... 23 more
Caused by: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:591)
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:443)
    at liquibase.ext.hibernate.database.HibernateSpringDatabase.buildConfigurationFromScanning(HibernateSpringDatabase.java:227)
    at liquibase.ext.hibernate.database.HibernateSpringDatabase.buildConfiguration(HibernateSpringDatabase.java:55)
    at liquibase.ext.hibernate.database.HibernateDatabase.setConnection(HibernateDatabase.java:45)
    at liquibase.database.DatabaseFactory.findCorrectDatabaseImplementation(DatabaseFactory.java:131)
    at liquibase.database.DatabaseFactory.openDatabase(DatabaseFactory.java:151)
    at liquibase.integration.commandline.CommandLineUtils.createDatabaseObject(CommandLineUtils.java:85)
    ... 25 more
Caused by: java.io.FileNotFoundException: class path resource [] cannot be resolved to URL because it does not exist
    at org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java:187)
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:588)
    ... 32 more
[ERROR] 
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

我可以确认数据库名称是正确的。并且 url 端口也应该是正确的。所以这个异常(exception)没有多大意义。

Answer 1

对我来说，解决方案是先用

mvn package