liquibase:diff command throws Null pointer exception - liquibase

Question

I generated liquibase schema with mvn liquibase:generateChangeLog, and when I try to execute the diff command with mvn liquibase:diff I get an error message Error getting default schema java.lang.NullPointerException. Not sure what's wrong with my configuration. I am testing Liquibase 3.6 with Spring Boot and Spring JPA
Error Message
mvn liquibase:diff
[INFO] Scanning for projects...
[INFO]
[INFO] -------------------------< com:liquibasetest >--------------------------
[INFO] Building liquibasetest 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- liquibase-maven-plugin:3.6.3:diff (default-cli) # liquibasetest ---
[INFO] ------------------------------------------------------------------------
[INFO] Parsing Liquibase Properties File
[INFO] File: src/main/resources/liquibase.properties
[INFO] 'outputChangeLogFile' in properties file is not being used by this task.
[INFO] ------------------------------------------------------------------------
[INFO] Starting Liquibase at Tue, 12 Feb 2019 00:05:05 EST (version 3.6.3 built at 2019-01-29 11:34:48)
[WARNING] Can not use class liquibase.ext.hibernate.database.HibernateSpringDatabase as a Liquibase service because org.springframework.beans.factory.support.BeanDefinitionRegistry is not in the classpath
[INFO] Executing on Database: jdbc:mysql://localhost:3306/flywaytest?currentSchema=flywaytest
[WARNING] Unknown database: Hibernate
[INFO] Performing Diff on database root#localhost # jdbc:mysql://localhost:3306/flywaytest?currentSchema=flywaytest (Default Schema: flywaytest)
[INFO] Error getting default schema
java.lang.NullPointerException
at liquibase.executor.jvm.JdbcExecutor$QueryCallableStatementCallback.doInCallableStatement (JdbcExecutor.java:452)
at liquibase.executor.jvm.JdbcExecutor.execute (JdbcExecutor.java:93)
at liquibase.executor.jvm.JdbcExecutor.query (JdbcExecutor.java:135)
at liquibase.executor.jvm.JdbcExecutor.query (JdbcExecutor.java:146)
at liquibase.executor.jvm.JdbcExecutor.queryForObject (JdbcExecutor.java:154)
at liquibase.executor.jvm.JdbcExecutor.queryForObject (JdbcExecutor.java:169)
at liquibase.executor.jvm.JdbcExecutor.queryForObject (JdbcExecutor.java:164)
at liquibase.database.AbstractJdbcDatabase.getConnectionSchemaName (AbstractJdbcDatabase.java:327)
at liquibase.database.AbstractJdbcDatabase.getDefaultSchemaName (AbstractJdbcDatabase.java:292)
at liquibase.CatalogAndSchema.customize (CatalogAndSchema.java:151)
at liquibase.snapshot.SnapshotGeneratorFactory.createSnapshot (SnapshotGeneratorFactory.java:184)
at liquibase.command.core.DiffCommand.createReferenceSnapshot (DiffCommand.java:221)
at liquibase.command.core.DiffCommand.createDiffResult (DiffCommand.java:143)
at liquibase.command.core.DiffToChangeLogCommand.run (DiffToChangeLogCommand.java:51)
at liquibase.command.AbstractCommand.execute (AbstractCommand.java:19)
at liquibase.integration.commandline.CommandLineUtils.doDiffToChangeLog (CommandLineUtils.java:237)
at liquibase.integration.commandline.CommandLineUtils.doDiffToChangeLog (CommandLineUtils.java:212)
at org.liquibase.maven.plugins.LiquibaseDatabaseDiff.performLiquibaseTask (LiquibaseDatabaseDiff.java:177)
at org.liquibase.maven.plugins.AbstractLiquibaseMojo.execute (AbstractLiquibaseMojo.java:366)
at org.liquibase.maven.plugins.LiquibaseDatabaseDiff.execute (LiquibaseDatabaseDiff.java:136)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:288)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:192)
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:498)
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)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.773 s
[INFO] Finished at: 2019-02-12T00:05:07-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.liquibase:liquibase-maven-plugin:3.6.3:diff (default-cli) on project liquibasetest: Error setting up or running Liquibase: liquibase.command.CommandExecutionException: java.lang.NullPointerException -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[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
liquibase.properties
outputChangeLogFile= src/main/resources/db/db.changelog-master.xml
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/flywaytest?currentSchema=flywaytest
username=root
password=bcmc1234
db.changlog-master.xml
<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog" xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.6.xsd">
<changeSet author="pjadda (generated)" id="1549947881457-1">
<createTable tableName="country">
<column name="id" type="BIGINT">
<constraints primaryKey="true"/>
</column>
<column name="name" type="VARCHAR(45)"/>
<column name="code" type="VARCHAR(45)"/>
<column name="iso_code" type="VARCHAR(45)"/>
<column name="region_id" type="BIGINT"/>
</createTable>
</changeSet>
<changeSet author="pjadda (generated)" id="1549947881457-2">
<createTable tableName="region">
<column name="id" type="BIGINT">
<constraints primaryKey="true"/>
</column>
<column name="name" type="VARCHAR(45)"/>
</createTable>
</changeSet>
<changeSet author="pjadda (generated)" id="1549947881457-3">
<createIndex indexName="region_fk_idx" tableName="country">
<column name="region_id"/>
</createIndex>
</changeSet>
<changeSet author="pjadda (generated)" id="1549947881457-4">
<addForeignKeyConstraint baseColumnNames="region_id" baseTableName="country" constraintName="region_fk" deferrable="false" initiallyDeferred="false" onDelete="NO ACTION" onUpdate="NO ACTION" referencedColumnNames="id" referencedTableName="region" validate="true"/>
</changeSet>
</databaseChangeLog>
pom.xml
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com</groupId>
<artifactId>liquibasetest</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>liquibasetest</name>
<description>Liquibase Test project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-boot.version>2.1.1.RELEASE</spring-boot.version>
<spring-boot-admin.version>2.1.1</spring-boot-admin.version>
<hibernate.version>5.4.0.Final</hibernate.version>
<liquibase-maven-plugin.version>3.6.3</liquibase-maven-plugin.version>
<liquibase-hibernate5.version>3.6</liquibase-hibernate5.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-envers</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-core</artifactId>
</dependency>
<dependency>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-maven-plugin</artifactId>
<version>${liquibase-maven-plugin.version}</version>
</dependency>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-client</artifactId>
</dependency>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<!-- <dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-dependencies</artifactId>
<version>${spring-boot-admin.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-maven-plugin</artifactId>
<version>${liquibase-maven-plugin.version}</version>
<configuration>
<propertyFile>src/main/resources/liquibase.properties</propertyFile>
<changeLogFile>src/main/resources/db/db.changelog-master.xml</changeLogFile>
<diffChangeLogFile>src/main/resources/db/changelog/${maven.build.timestamp}_changelog.xml</diffChangeLogFile>
<logging>info</logging>
</configuration>
<!-- <executions>
<execution>
<id>generate-db-prev</id>
<phase>process-resources</phase>
<goals>
<goal>update</goal>
</goals>
<configuration>
<dropFirst>true</dropFirst>
</configuration>
</execution>
<execution>
<id>generate-db-diff</id>
<phase>process-test-resources</phase>
<goals>
<goal>diff</goal>
</goals>
</execution>
</executions>-->
<dependencies>
<dependency>
<groupId>org.liquibase.ext</groupId>
<artifactId>liquibase-hibernate4</artifactId>
<version>3.6</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>

Answer 1

Update: As of 03-Jun-2019 latest liquibase version 3.6.3 and liquibase-hibernate5 plugin version 3.7 have a bug and will update the post once it's resolved. Meanwhile, use liquibase-maven-plugin version 3.5.5 and liquibase-hibernate5 version 3.6
Solution:
I figured out the issue. Spring JPA uses Hibernate 5.x and I configured liquibase-hibernate4 in liquibase dependencies. Thanks to Steve Donnie for pointing out the warning message. Changing liquibase version created another exception related Spring JPA, so I moved Spring JPA dependency to liquibase dependencies and added
validation-api dependency to prevent validation errors
<dependencies>
<dependency>
<groupId>org.liquibase.ext</groupId>
<artifactId>liquibase-hibernate5</artifactId>
<version>${liquibase-hibernate5.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>${spring-boot.version}</version>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>${validation-api.version}</version>
</dependency>
</dependencies>
so updated pom.xml is as below
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com</groupId>
<artifactId>liquibasetest</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>liquibasetest</name>
<description>Liquibase Test project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-boot.version>2.1.2.RELEASE</spring-boot.version>
<spring-boot-admin.version>2.1.1</spring-boot-admin.version>
<hibernate.version>5.4.0.Final</hibernate.version>
<liquibase-maven-plugin.version>3.5.5</liquibase-maven-plugin.version>
<liquibase-hibernate5.version>3.6</liquibase-hibernate5.version>
<validation-api.version>2.0.1.Final</validation-api.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-envers</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-client</artifactId>
</dependency>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-core</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-maven-plugin</artifactId>
<version>${liquibase-maven-plugin.version}</version>
</dependency>
<!-- <dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-dependencies</artifactId>
<version>${spring-boot-admin.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.liquibase</groupId>
<artifactId>liquibase-maven-plugin</artifactId>
<version>${liquibase-maven-plugin.version}</version>
<configuration>
<propertyFile>src/main/resources/liquibase.properties</propertyFile>
<changeLogFile>src/main/resources/db/db.changelog-master.xml</changeLogFile>
<diffChangeLogFile>src/main/resources/db/changelog/${maven.build.timestamp}_changelog.xml</diffChangeLogFile>
<logging>debug</logging>
</configuration>
<dependencies>
<dependency>
<groupId>org.liquibase.ext</groupId>
<artifactId>liquibase-hibernate5</artifactId>
<version>${liquibase-hibernate5.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>${spring-boot.version}</version>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>${validation-api.version}</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>