org.eclipse.gemini.blueprint.util

Class DebugUtils

java.lang.Object

org.eclipse.gemini.blueprint.util.DebugUtils

public abstract class DebugUtils
extends java.lang.Object

Utility class used for debugging exceptions in OSGi environment, such as class loading errors. The main entry point is debugClassLoadingThrowable(Throwable, Bundle, Class[]) which will try to determine the cause by trying to load the given interfaces using the given bundle.

The debugging process can be potentially expensive.

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	COMMA
private static java.lang.String	DOUBLE_QUOTE
private static java.lang.String	EQUALS
private static org.apache.commons.logging.Log	log use degradable logger
private static java.util.regex.Pattern	PACKAGE_PATTERN
private static java.lang.String	PACKAGE_REGEX
private static java.lang.String	SEMI_COLON

Constructor Summary

Constructors

Constructor and Description
DebugUtils()

Method Summary

Modifier and Type	Method and Description
private static org.osgi.framework.Version	checkBundleForClass(org.osgi.framework.Bundle bundle, java.lang.String name, org.osgi.framework.Version iversion)
private static java.net.URL	checkBundleJarsForClass(org.osgi.framework.Bundle bundle, java.lang.String name)
static void	debugClassLoading(org.osgi.framework.Bundle bundle, java.lang.String className, java.lang.String rootClassName) Tries (through a best-guess attempt) to figure out why a given class could not be found.
static void	debugClassLoadingThrowable(java.lang.Throwable loadingThrowable, org.osgi.framework.Bundle bundle, java.lang.Class<?>[] classes) Tries to debug the cause of the Throwables that can appear when loading classes in OSGi environments (for example when creating proxies).
private static org.osgi.framework.Version	getVersion(java.lang.String stmt, java.lang.String packageName) Get the version of a package name.
private static org.osgi.framework.Version	hasExport(org.osgi.framework.Bundle bundle, java.lang.String packageName)
private static org.osgi.framework.Version	hasImport(org.osgi.framework.Bundle bundle, java.lang.String packageName) Get the version of a package import from a bundle.
private static java.lang.String[]	splitIntoPackages(java.lang.String stmt)

Methods inherited from class java.lang.Object

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

Field Detail

EQUALS

private static final java.lang.String EQUALS

See Also:

Constant Field Values

DOUBLE_QUOTE

private static final java.lang.String DOUBLE_QUOTE

See Also:

Constant Field Values

SEMI_COLON

private static final java.lang.String SEMI_COLON

See Also:

Constant Field Values

COMMA

private static final java.lang.String COMMA

See Also:

Constant Field Values

log

private static final org.apache.commons.logging.Log log

use degradable logger

PACKAGE_REGEX

private static final java.lang.String PACKAGE_REGEX

See Also:

Constant Field Values

PACKAGE_PATTERN

private static final java.util.regex.Pattern PACKAGE_PATTERN

Constructor Detail

DebugUtils

public DebugUtils()

Method Detail

debugClassLoadingThrowable

public static void debugClassLoadingThrowable(java.lang.Throwable loadingThrowable,
                                              org.osgi.framework.Bundle bundle,
                                              java.lang.Class<?>[] classes)

Tries to debug the cause of the Throwables that can appear when loading classes in OSGi environments (for example when creating proxies).

This method will try to determine the class that caused the problem and to search for it in the given bundle or through the classloaders of the given classes. It will look at the classes are visible by the given bundle on debug level and do a bundle discovery process on trace level. The method accepts also an array of classes which will be used for loading the 'problematic' class that caused the exception on debug level.

Parameters:

loadingThrowable - class loading Throwable (such as NoClassDefFoundError or ClassNotFoundException)

bundle - bundle used for loading the classes

classes - (optional) array of classes that will be used for loading the problematic class

debugClassLoading

public static void debugClassLoading(org.osgi.framework.Bundle bundle,
                                     java.lang.String className,
                                     java.lang.String rootClassName)

Tries (through a best-guess attempt) to figure out why a given class could not be found. This method will search the given bundle and its classpath to determine the reason for which the class cannot be loaded.

This method tries to be effective especially when the dealing with NoClassDefFoundError caused by failure of loading transitive classes (such as getting a NCDFE when loading foo.A because bar.B cannot be found).

Parameters:

bundle - the bundle to search for (and which should do the loading)

className - the name of the class that failed to be loaded in dot format (i.e. java.lang.Thread)

rootClassName - the name of the class that triggered the loading (i.e. java.lang.Runnable)

checkBundleForClass

private static org.osgi.framework.Version checkBundleForClass(org.osgi.framework.Bundle bundle,
                                                              java.lang.String name,
                                                              org.osgi.framework.Version iversion)

checkBundleJarsForClass

private static java.net.URL checkBundleJarsForClass(org.osgi.framework.Bundle bundle,
                                                    java.lang.String name)

hasImport

private static org.osgi.framework.Version hasImport(org.osgi.framework.Bundle bundle,
                                                    java.lang.String packageName)

Get the version of a package import from a bundle.

Parameters:

bundle -

packageName -

Returns:

hasExport

private static org.osgi.framework.Version hasExport(org.osgi.framework.Bundle bundle,
                                                    java.lang.String packageName)

getVersion

private static org.osgi.framework.Version getVersion(java.lang.String stmt,
                                                     java.lang.String packageName)

Get the version of a package name.

Parameters:

stmt -

packageName -

Returns:

splitIntoPackages

private static java.lang.String[] splitIntoPackages(java.lang.String stmt)