com.edugility.maven.liquibase

Class AggregateChangeLogGenerator

java.lang.Object

com.edugility.maven.liquibase.AggregateChangeLogGenerator

public class AggregateChangeLogGenerator
extends Object

A generator that creates a Liquibase changelog file with <include> elements inside it referencing other Liquibase changelog fragments.

This class is chiefly for use by a LiquibaseChangeLogArtifactsProcessor.

Author:

Laird Nelson

See Also:

LiquibaseChangeLogArtifactsProcessor, The documentation for the artifact-maven-plugin, The Liquibase homepage, Documentation relating to the Liquibase changelog file

Constructor Summary

Constructors

Constructor and Description
AggregateChangeLogGenerator() Creates a new AggregateChangeLogGenerator.

Method Summary

Modifier and Type	Method and Description
File	generate(Collection<? extends URL> resources) Generates a Liquibase changelog file that, from a high level, logically contains the Liquibase changelog fragments reachable from the supplied URLs.
protected File	generateEmptyAggregateChangeLogFile() Generates an empty (temporary) File that will eventually contain Liquibase changelog contents.
File	getAggregateChangeLogFile() Returns a File that either does house or will house Liquibase changelog contents.
String	getCharacterSet()
String	getDatabaseChangeLogXsdVersion() Returns the version of the Liquibase changelog file that will be generated.
Properties	getProperties() Returns a Properties object representing any custom properties that are to be converted to Liquibase changelog parameters.
protected URL	getResource(String name) Loads a notional resource with the given name from the classpath.
String	getTemplate() Returns the source code of an MVEL template that represents the skeleton of a Liquibase changelog into which will be placed <include> elements.
void	setAggregateChangeLogFile(File file) Installs a File representing the path to a file that will be erased and that will eventually contain Liquibase changelog contents.
void	setCharacterSet(String characterSet)
void	setDatabaseChangeLogXsdVersion(String version) Sets the version of the Liquibase changelog file that will be generated.
void	setProperties(Properties properties) Installs a Properties object that represents custom properties that are to be converted to Liquibase changelog parameters.
void	setTemplate(String template) Sets the source code of an MVEL template that will be used to produce a Liquibase changelog.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AggregateChangeLogGenerator

public AggregateChangeLogGenerator()

Creates a new AggregateChangeLogGenerator.

Method Detail

getDatabaseChangeLogXsdVersion

public String getDatabaseChangeLogXsdVersion()

Returns the version of the Liquibase changelog file that will be generated.

This method may return null in which case "3.3" will be used internally instead.

By default, "3.3" is returned, and this default value will change when Liquibase is updated and this project is updated to depend on it.

Returns:

the version of the Liquibase changelog file that will be generated, or null

See Also:

setDatabaseChangeLogXsdVersion(String)

setDatabaseChangeLogXsdVersion

public void setDatabaseChangeLogXsdVersion(String version)

Sets the version of the Liquibase changelog file that will be generated.

Parameters:

version - the new version; may be null

See Also:

getDatabaseChangeLogXsdVersion()

getResource

protected URL getResource(String name)

Loads a notional resource with the given name from the classpath.

The default implementation invokes the ClassLoader.getResource(String) method on the supplied String using, in order:

1. the context ClassLoader
2. this class' ClassLoader

The first of these ClassLoaders to return a non-null value will have its result returned. Otherwise, the return value of ClassLoader.getSystemResource(String) is returned.

Parameters:

name - the name of the resource to load; may be null in which case null will be returned

Returns:

the resource that was found, or null

See Also:

ClassLoader.getResource(String)

getProperties

public Properties getProperties()

Returns a Properties object representing any custom properties that are to be converted to Liquibase changelog parameters.

This method may return null.

Returns:

a Properties object representing custom properties, or null

See Also:

setProperties(Properties)

setProperties

public void setProperties(Properties properties)

Installs a Properties object that represents custom properties that are to be converted to Liquibase changelog parameters.

Parameters:

properties - the Properties to be installed; may be null

See Also:

getProperties()

getCharacterSet

public String getCharacterSet()

setCharacterSet

public void setCharacterSet(String characterSet)

getTemplate

public String getTemplate()

Returns the source code of an MVEL template that represents the skeleton of a Liquibase changelog into which will be placed <include> elements.

This method will not return null and overrides of it must not either.

Returns:

a non-null String containing the source code of an MVEL template

setTemplate

public void setTemplate(String template)

Sets the source code of an MVEL template that will be used to produce a Liquibase changelog.

Parameters:

template - the new source code; must not be null

Throws:

IllegalArgumentException - if template is null

See Also:

getTemplate()

getAggregateChangeLogFile

public File getAggregateChangeLogFile()

Returns a File that either does house or will house Liquibase changelog contents.

This method may return null.

This method may generate such a file.

Returns:

a File representing the aggregate changelog, or null

See Also:

generateEmptyAggregateChangeLogFile()

setAggregateChangeLogFile

public void setAggregateChangeLogFile(File file)

Installs a File representing the path to a file that will be erased and that will eventually contain Liquibase changelog contents.

Parameters:

file - a path to a file that will be used as the Liquibase changelog file generated by this AggregateChangeLogGenerator; may be null

generateEmptyAggregateChangeLogFile

protected File generateEmptyAggregateChangeLogFile()
                                            throws IOException

Generates an empty (temporary) File that will eventually contain Liquibase changelog contents.

This implementation calls File.createTempFile(String, String) with changelog and .tmp.xml as its arguments, instructs the File so created to be deleted when the Java Virtual Machine exits and returns the result.

Returns:

a non-null File

Throws:

IOException - if an error occurs

generate

public File generate(Collection<? extends URL> resources)
              throws IOException

Generates a Liquibase changelog file that, from a high level, logically contains the Liquibase changelog fragments reachable from the supplied URLs.

This method never returns null.

Parameters:

resources - a Collection of URLs, each element of which resolves to a Liquibase changelog file; may be null or empty in whihc case a generally useless changelog will be generated

Returns:

a non-null File representing the path to the generated file

Throws:

IOException - if an error occurs

IllegalStateException - if somehow the File into which content will be poured is null

See Also:

getAggregateChangeLogFile(), generateEmptyAggregateChangeLogFile()