Package org.pf4j

Class DependencyResolver

java.lang.Object

org.pf4j.DependencyResolver

public class DependencyResolver
extends java.lang.Object

This class builds a dependency graph for a list of plugins (descriptors). The entry point is the resolve(List) method, method that returns a DependencyResolver.Result object. The Result class contains nice information about the result of resolve operation (if it's a cyclic dependency, they are not found dependencies, they are dependencies with wrong version). This class is very useful for if-else scenarios. Only some attributes (pluginId, dependencies and pluginVersion) from PluginDescriptor are used in the process of resolve operation.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DependencyResolver.CyclicDependencyException	It will be thrown if a cyclic dependency is detected.
static class	DependencyResolver.DependenciesNotFoundException	Indicates that the dependencies required were not found.
static class	DependencyResolver.DependenciesWrongVersionException	Indicates that some dependencies have wrong version.
static class	DependencyResolver.Result
static class	DependencyResolver.WrongDependencyVersion

Field Summary

Fields

Modifier and Type	Field	Description
private DirectedGraph<java.lang.String>	dependenciesGraph
private DirectedGraph<java.lang.String>	dependentsGraph
private static org.slf4j.Logger	log
private boolean	resolved
private VersionManager	versionManager

Constructor Summary

Constructors

Constructor	Description
DependencyResolver(VersionManager versionManager)

Method Summary

Modifier and Type	Method	Description
private void	addPlugin(PluginDescriptor descriptor)
protected boolean	checkDependencyVersion(java.lang.String requiredVersion, java.lang.String existingVersion)	Check if an existing version of dependency is compatible with the required version (from plugin descriptor).
private void	checkResolved()
java.util.List<java.lang.String>	getDependencies(java.lang.String pluginId)	Retrieves the plugins ids that the given plugin id directly depends on.
private java.lang.String	getDependencyVersionSupport(PluginDescriptor dependent, java.lang.String dependencyId)
java.util.List<java.lang.String>	getDependents(java.lang.String pluginId)	Retrieves the plugins ids that the given content is a direct dependency of.
DependencyResolver.Result	resolve(java.util.List<PluginDescriptor> plugins)

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final org.slf4j.Logger log

versionManager

private VersionManager versionManager

dependenciesGraph

private DirectedGraph<java.lang.String> dependenciesGraph

dependentsGraph

private DirectedGraph<java.lang.String> dependentsGraph

resolved

private boolean resolved

Constructor Detail

DependencyResolver

public DependencyResolver(VersionManager versionManager)

Method Detail

resolve

public DependencyResolver.Result resolve(java.util.List<PluginDescriptor> plugins)

getDependencies

public java.util.List<java.lang.String> getDependencies(java.lang.String pluginId)

Retrieves the plugins ids that the given plugin id directly depends on.

Parameters:

pluginId - the unique plugin identifier, specified in its metadata

Returns:

getDependents

public java.util.List<java.lang.String> getDependents(java.lang.String pluginId)

Retrieves the plugins ids that the given content is a direct dependency of.

Parameters:

pluginId - the unique plugin identifier, specified in its metadata

Returns:

checkDependencyVersion

protected boolean checkDependencyVersion(java.lang.String requiredVersion,
                                         java.lang.String existingVersion)

Check if an existing version of dependency is compatible with the required version (from plugin descriptor).

Parameters:

requiredVersion -

existingVersion -

Returns:

addPlugin

private void addPlugin(PluginDescriptor descriptor)

checkResolved

private void checkResolved()

getDependencyVersionSupport

private java.lang.String getDependencyVersionSupport(PluginDescriptor dependent,
                                                     java.lang.String dependencyId)