org.apache.brooklyn.util.core

Class ClassLoaderUtils

java.lang.Object

org.apache.brooklyn.util.core.ClassLoaderUtils

public class ClassLoaderUtils
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
ClassLoaderUtils(java.lang.Class<?> callingClass)
ClassLoaderUtils(java.lang.Class<?> callingClass, Entity entity)
ClassLoaderUtils(java.lang.Class<?> callingClass, ManagementContext mgmt)
ClassLoaderUtils(java.lang.ClassLoader cl)
ClassLoaderUtils(java.lang.ClassLoader cl, ManagementContext mgmt)
ClassLoaderUtils(java.lang.Object callingObj, Entity entity)
ClassLoaderUtils(java.lang.Object callingObj, ManagementContext mgmt)

Method Summary

Modifier and Type	Method and Description
java.net.URL	getResource(java.lang.String name) Finds the resource with the given name.
java.lang.Iterable<java.net.URL>	getResources(java.lang.String name) Finds all the resources with the given name.
boolean	isBundleWhiteListed(org.osgi.framework.Bundle bundle)
java.lang.Class<?>	loadClass(java.lang.String name) Loads the given class, handle OSGi bundles.
java.lang.Class<?>	loadClass(java.lang.String symbolicName, java.lang.String version, java.lang.String className)
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ClassLoaderUtils

public ClassLoaderUtils(java.lang.Object callingObj,
                        Entity entity)

ClassLoaderUtils

public ClassLoaderUtils(java.lang.Object callingObj,
                        @Nullable
                        ManagementContext mgmt)

ClassLoaderUtils

public ClassLoaderUtils(java.lang.Class<?> callingClass)

ClassLoaderUtils

public ClassLoaderUtils(@Nullable
                        java.lang.ClassLoader cl)

ClassLoaderUtils

public ClassLoaderUtils(@Nullable
                        java.lang.ClassLoader cl,
                        @Nullable
                        ManagementContext mgmt)

ClassLoaderUtils

public ClassLoaderUtils(java.lang.Class<?> callingClass,
                        Entity entity)

ClassLoaderUtils

public ClassLoaderUtils(java.lang.Class<?> callingClass,
                        @Nullable
                        ManagementContext mgmt)

Method Detail

loadClass

public java.lang.Class<?> loadClass(java.lang.String name)
                             throws java.lang.ClassNotFoundException

Loads the given class, handle OSGi bundles. The class could be in one of the following formats:

• <classname>, such as com.google.common.net.HostAndPort
• <bunde-symbolicName>:<classname>, such as com.google.guava:com.google.common.net.HostAndPort
• <bunde-symbolicName>:<bundle-version>:<classname>, such as com.google.guava:16.0.1:com.google.common.net.HostAndPort

The classloading order is as follows:

1. If the class explicitly states the bundle name and version, then load from that.
2. Otherwise try to load from the catalog's classloader. This is so we respect any libraries supplied in the catalog metadata, and can thus handle updating catalog versions. It also means we can try our best to handle a catalog that uses a different bundle version from something that ships with Brooklyn.
3. The white-listed bundles (i.e. those that ship with Brooklyn). We prefer the version of the bundle that Brooklyn depends on, rather than taking the highest version installed (e.g. Karaf has Guava 16.0.1 and 18.0; we want the former, which Brooklyn uses).
4. The classloader passed in. Normally this is a boring unhelpful classloader (e.g. obtained from callingClass.getClassLoader()), so won't work. But it's up to the caller if they pass in something more useful.
5. The ManagementContext.getCatalogClassLoader(). Again, this is normally not helpful. We instead would prefer the specific catalog item's classloader (which we tried earlier).
6. If we were given a bundle name without a version, then finally try just using the most recent version of the bundle that is available in the OSGi container.

The list of "white-listed bundles" are controlled using the system property named WHITE_LIST_KEY, defaulting to all org.apache.brooklyn.* bundles.

Throws:

java.lang.ClassNotFoundException

loadClass

public java.lang.Class<?> loadClass(java.lang.String symbolicName,
                                    @Nullable
                                    java.lang.String version,
                                    java.lang.String className)
                             throws java.lang.ClassNotFoundException

Throws:

java.lang.ClassNotFoundException

getResource

public java.net.URL getResource(java.lang.String name)

Finds the resource with the given name.

Returns:

null when no resource is found

See Also:

#loadClass(String)} for loading order

getResources

public java.lang.Iterable<java.net.URL> getResources(java.lang.String name)

Finds all the resources with the given name. Aborts going through subsequent fallbacks when it finds at least one resource.

Returns:

empty Iterable when no resources find

See Also:

#loadClass(String)} for loading order

isBundleWhiteListed

public boolean isBundleWhiteListed(org.osgi.framework.Bundle bundle)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object