Package org.apache.tools.ant
Class AntClassLoader
java.lang.Object
java.lang.ClassLoader
org.apache.tools.ant.AntClassLoader
- All Implemented Interfaces:
- Closeable,- AutoCloseable,- EventListener,- BuildListener,- SubBuildListener
- Direct Known Subclasses:
- AntClassLoader2,- AntClassLoader5,- SplitClassLoader
Used to load classes within ant with a different classpath from
 that used to start ant. Note that it is possible to force a class
 into this loader even when that class is on the system classpath by
 using the forceLoadClass method. Any subsequent classes loaded by that
 class will then use this loader rather than the system class loader.
 
Note that this classloader has a feature to allow loading in reverse order and for "isolation". Due to the fact that a number of methods in java.lang.ClassLoader are final (at least in java 1.4 getResources) this means that the class has to fake the given parent.
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Constructor SummaryConstructorsConstructorDescriptionCreate an Ant Class LoaderAntClassLoader(ClassLoader parent, boolean parentFirst) Creates an empty class loader.AntClassLoader(ClassLoader parent, Project project, Path classpath) Create an Ant ClassLoader for a given project, with a parent classloader and an initial classpath.AntClassLoader(ClassLoader parent, Project project, Path classpath, boolean parentFirst) Creates a classloader for the given project using the classpath given.AntClassLoader(Project project, Path classpath) Creates a classloader for the given project using the classpath given.AntClassLoader(Project project, Path classpath, boolean parentFirst) Creates a classloader for the given project using the classpath given.
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Method SummaryModifier and TypeMethodDescriptionvoidadd any libraries that come with different java versions herevoidaddLoaderPackageRoot(String packageRoot) Adds a package root to the list of packages which must be loaded using this loader.voidaddPathComponent(File file) Add a path component.voidaddPathElement(String pathElement) Adds an element to the classpath to be searched.protected voidaddPathFile(File pathComponent) Add a file to the path.voidaddSystemPackageRoot(String packageRoot) Adds a package root to the list of packages which must be loaded on the parent loader.voidbuildFinished(BuildEvent event) Cleans up any resources held by this classloader at the end of a build.voidbuildStarted(BuildEvent event) Empty implementation to satisfy the BuildListener interface.voidcleanup()Cleans up any resources held by this classloader.voidclose()protected Class<?> defineClassFromData(File container, byte[] classData, String classname) Define a class given its bytesprotected voiddefinePackage(File container, String className) Define the package information associated with a class.protected voiddefinePackage(File container, String packageName, Manifest manifest) Define the package information when the class comes from a jar with a manifestClass<?> Searches for and load a class on the classpath of this class loader.protected URLfindResource(String name) Finds the resource with the given name.protected Enumeration<URL> findResources(String name) Returns an enumeration of URLs representing all the resources with the given name by searching the class loader's classpath.protected Enumeration<URL> findResources(String name, boolean skipParent) Returns an enumeration of URLs representing all the resources with the given name by searching the class loader's classpath.Class<?> forceLoadClass(String classname) Loads a class through this class loader even if that class is available on the parent classpath.Class<?> forceLoadSystemClass(String classname) Loads a class through this class loader but defer to the parent class loader.Returns the classpath this classloader will consult.Gets the parent as has been specified in the constructor or via setParent.getNamedResources(String name) Finds all the resources with the given name.getResource(String name) Finds the resource with the given name.getResourceAsStream(String name) Returns a stream to read the requested resource name.getResources(String name) protected URLgetResourceURL(File file, String resourceName) Returns the URL of a given resource in the given file which may either be a directory or a zip file.static voidinitializeClass(Class<?> theClass) Deprecated.since 1.6.x.protected booleanIndicate if the given file is in this loader's pathprotected Class<?> Loads a class with this class loader.protected voidLogs a message through the project object if one has been provided.voidmessageLogged(BuildEvent event) Empty implementation to satisfy the BuildListener interface.static AntClassLoadernewAntClassLoader(ClassLoader parent, Project project, Path path, boolean parentFirst) Factory methodvoidResets the current thread's context loader to its original value.voidsetClassPath(Path classpath) Set the classpath to search for classes to load.voidsetIsolated(boolean isolated) Sets whether this classloader should run in isolated mode.voidsetParent(ClassLoader parent) Set the parent for this class loader.voidsetParentFirst(boolean parentFirst) Control whether class lookup is delegated to the parent loader first or after this loader.voidsetProject(Project project) Set the project associated with this class loadervoidSets the current thread's context loader to this classloader, storing the current loader value for later resetting.voidsubBuildFinished(BuildEvent event) Cleans up any resources held by this classloader at the end of a subbuild if it has been created for the subbuild's project instance.voidsubBuildStarted(BuildEvent event) Empty implementation to satisfy the BuildListener interface.voidtargetFinished(BuildEvent event) Empty implementation to satisfy the BuildListener interface.voidtargetStarted(BuildEvent event) Empty implementation to satisfy the BuildListener interface.voidtaskFinished(BuildEvent event) Empty implementation to satisfy the BuildListener interface.voidtaskStarted(BuildEvent event) Empty implementation to satisfy the BuildListener interface.toString()Returns aStringrepresenting this loader.Methods inherited from class java.lang.ClassLoaderclearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findSystemClass, getClassLoadingLock, getDefinedPackage, getDefinedPackages, getName, getPackage, getPackages, getParent, getPlatformClassLoader, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, getUnnamedModule, isRegisteredAsParallelCapable, loadClass, registerAsParallelCapable, resolveClass, resources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners
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Constructor Details- 
AntClassLoaderCreate an Ant ClassLoader for a given project, with a parent classloader and an initial classpath.- Parameters:
- parent- the parent for this classloader.
- project- The project to which this classloader is to belong.
- classpath- The classpath to use to load classes.
- Since:
- Ant 1.7.
 
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AntClassLoaderpublic AntClassLoader()Create an Ant Class Loader
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AntClassLoaderCreates a classloader for the given project using the classpath given.- Parameters:
- project- The project to which this classloader is to belong. Must not be- null.
- classpath- The classpath to use to load the classes. This is combined with the system classpath in a manner determined by the value of ${build.sysclasspath}. May be- null, in which case no path elements are set up to start with.
 
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AntClassLoaderCreates a classloader for the given project using the classpath given.- Parameters:
- parent- The parent classloader to which unsatisfied loading attempts are delegated. May be- null, in which case the classloader which loaded this class is used as the parent.
- project- The project to which this classloader is to belong. Must not be- null.
- classpath- the classpath to use to load the classes. May be- null, in which case no path elements are set up to start with.
- parentFirst- If- true, indicates that the parent classloader should be consulted before trying to load the a class through this loader.
 
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AntClassLoaderCreates a classloader for the given project using the classpath given.- Parameters:
- project- The project to which this classloader is to belong. Must not be- null.
- classpath- The classpath to use to load the classes. May be- null, in which case no path elements are set up to start with.
- parentFirst- If- true, indicates that the parent classloader should be consulted before trying to load the a class through this loader.
 
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AntClassLoaderCreates an empty class loader. The classloader should be configured with path elements to specify where the loader is to look for classes.- Parameters:
- parent- The parent classloader to which unsatisfied loading attempts are delegated. May be- null, in which case the classloader which loaded this class is used as the parent.
- parentFirst- If- true, indicates that the parent classloader should be consulted before trying to load the a class through this loader.
 
 
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Method Details- 
setProjectSet the project associated with this class loader- Parameters:
- project- the project instance
 
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setClassPathSet the classpath to search for classes to load. This should not be changed once the classloader starts to server classes- Parameters:
- classpath- the search classpath consisting of directories and jar/zip files.
 
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setParentSet the parent for this class loader. This is the class loader to which this class loader will delegate to load classes- Parameters:
- parent- the parent class loader.
 
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setParentFirstpublic void setParentFirst(boolean parentFirst) Control whether class lookup is delegated to the parent loader first or after this loader. Use with extreme caution. Setting this to false violates the class loader hierarchy and can lead to Linkage errors- Parameters:
- parentFirst- if true, delegate initial class search to the parent classloader.
 
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logLogs a message through the project object if one has been provided.- Parameters:
- message- The message to log. Should not be- null.
- priority- The logging priority of the message.
 
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setThreadContextLoaderpublic void setThreadContextLoader()Sets the current thread's context loader to this classloader, storing the current loader value for later resetting.
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resetThreadContextLoaderpublic void resetThreadContextLoader()Resets the current thread's context loader to its original value.
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addPathElementAdds an element to the classpath to be searched.- Parameters:
- pathElement- The path element to add. Must not be- null.
- Throws:
- BuildException- if the given path element cannot be resolved against the project.
 
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addPathComponentAdd a path component. This simply adds the file, unlike addPathElement it does not open jar files and load files from their CLASSPATH entry in the manifest file.- Parameters:
- file- the jar file or directory to add.
 
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addPathFileAdd a file to the path. Reads the manifest, if available, and adds any additional class path jars specified in the manifest.- Parameters:
- pathComponent- the file which is to be added to the path for this class loader
- Throws:
- IOException- if data needed from the file cannot be read.
 
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getClasspathReturns the classpath this classloader will consult.- Returns:
- the classpath used for this classloader, with elements separated by the path separator for the system.
 
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setIsolatedpublic void setIsolated(boolean isolated) Sets whether this classloader should run in isolated mode. In isolated mode, classes not found on the given classpath will not be referred to the parent class loader but will cause a ClassNotFoundException.- Parameters:
- isolated- Whether or not this classloader should run in isolated mode.
 
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initializeClassDeprecated.since 1.6.x. Use Class.forName with initialize=true instead.Forces initialization of a class in a JDK 1.1 compatible, albeit hacky way.- Parameters:
- theClass- The class to initialize. Must not be- null.
 
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addSystemPackageRootAdds a package root to the list of packages which must be loaded on the parent loader. All subpackages are also included.- Parameters:
- packageRoot- The root of all packages to be included. Should not be- null.
 
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addLoaderPackageRootAdds a package root to the list of packages which must be loaded using this loader. All subpackages are also included.- Parameters:
- packageRoot- The root of all packages to be included. Should not be- null.
 
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forceLoadClassLoads a class through this class loader even if that class is available on the parent classpath. This ensures that any classes which are loaded by the returned class will use this classloader.- Parameters:
- classname- The name of the class to be loaded. Must not be- null.
- Returns:
- the required Class object
- Throws:
- ClassNotFoundException- if the requested class does not exist on this loader's classpath.
 
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forceLoadSystemClassLoads a class through this class loader but defer to the parent class loader. This ensures that instances of the returned class will be compatible with instances which have already been loaded on the parent loader.- Parameters:
- classname- The name of the class to be loaded. Must not be- null.
- Returns:
- the required Class object
- Throws:
- ClassNotFoundException- if the requested class does not exist on this loader's classpath.
 
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getResourceAsStreamReturns a stream to read the requested resource name.- Overrides:
- getResourceAsStreamin class- ClassLoader
- Parameters:
- name- The name of the resource for which a stream is required. Must not be- null.
- Returns:
- a stream to the required resource or nullif the resource cannot be found on the loader's classpath.
 
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getResourceFinds the resource with the given name. A resource is some data (images, audio, text, etc) that can be accessed by class code in a way that is independent of the location of the code.- Overrides:
- getResourcein class- ClassLoader
- Parameters:
- name- The name of the resource for which a stream is required. Must not be- null.
- Returns:
- a URL for reading the resource, or nullif the resource could not be found or the caller doesn't have adequate privileges to get the resource.
 
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getNamedResourcesFinds all the resources with the given name. A resource is some data (images, audio, text, etc) that can be accessed by class code in a way that is independent of the location of the code.- Parameters:
- name- name of the resource
- Returns:
- possible URLs as enumeration
- Throws:
- IOException- if something goes wrong
- Since:
- Ant 1.8.0
- See Also:
 
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findResourceFinds the resource with the given name.- Overrides:
- findResourcein class- ClassLoader
- Parameters:
- name- The resource name
- Returns:
- A URLobject for reading the resource, ornullif the resource could not be found
 
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findResourcesReturns an enumeration of URLs representing all the resources with the given name by searching the class loader's classpath.- Overrides:
- findResourcesin class- ClassLoader
- Parameters:
- name- The resource name to search for. Must not be- null.
- Returns:
- an enumeration of URLs for the resources
- Throws:
- IOException- if I/O errors occurs (can't happen)
 
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findResourcesReturns an enumeration of URLs representing all the resources with the given name by searching the class loader's classpath.- Parameters:
- name- The resource name to search for. Must not be- null.
- skipParent- whether to skip searching the parent first - will be false if the method is invoked from- getResources(String)or- getNamedResources(String)and true if the method is invoked from- findResources(String).
- Returns:
- an enumeration of URLs for the resources
- Throws:
- IOException- if I/O errors occurs (can't happen)
 
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getResourceURLReturns the URL of a given resource in the given file which may either be a directory or a zip file.- Parameters:
- file- The file (directory or jar) in which to search for the resource. Must not be- null.
- resourceName- The name of the resource for which a stream is required. Must not be- null.
- Returns:
- a stream to the required resource or nullif the resource cannot be found in the given file object.
 
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loadClassLoads a class with this class loader. This class attempts to load the class in an order determined by whether or not the class matches the system/loader package lists, with the loader package list taking priority. If the classloader is in isolated mode, failure to load the class in this loader will result in a ClassNotFoundException.- Overrides:
- loadClassin class- ClassLoader
- Parameters:
- classname- The name of the class to be loaded. Must not be- null.
- resolve-- trueif all classes upon which this class depends are to be loaded.
- Returns:
- the required Class object
- Throws:
- ClassNotFoundException- if the requested class does not exist on the system classpath (when not in isolated mode) or this loader's classpath.
 
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defineClassFromDataprotected Class<?> defineClassFromData(File container, byte[] classData, String classname) throws IOException Define a class given its bytes- Parameters:
- container- the container from which the class data has been read may be a directory or a jar/zip file.
- classData- the bytecode data for the class
- classname- the name of the class
- Returns:
- the Class instance created from the given data
- Throws:
- IOException- if the class data cannot be read.
 
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definePackageDefine the package information associated with a class.- Parameters:
- container- the file containing the class definition.
- className- the class name of for which the package information is to be determined.
- Throws:
- IOException- if the package information cannot be read from the container.
 
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definePackageDefine the package information when the class comes from a jar with a manifest- Parameters:
- container- the jar file containing the manifest
- packageName- the name of the package being defined.
- manifest- the jar's manifest
 
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findClassSearches for and load a class on the classpath of this class loader.- Overrides:
- findClassin class- ClassLoader
- Parameters:
- name- The name of the class to be loaded. Must not be- null.
- Returns:
- the required Class object
- Throws:
- ClassNotFoundException- if the requested class does not exist on this loader's classpath.
 
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isInPathIndicate if the given file is in this loader's path- Parameters:
- component- the file which is to be checked
- Returns:
- true if the file is in the class path
 
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cleanuppublic void cleanup()Cleans up any resources held by this classloader. Any open archive files are closed.
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getConfiguredParentGets the parent as has been specified in the constructor or via setParent.- Returns:
- classloader
- Since:
- Ant 1.8.0
 
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buildStartedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- buildStartedin interface- BuildListener
- Parameters:
- event- the buildStarted event
 
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buildFinishedCleans up any resources held by this classloader at the end of a build.- Specified by:
- buildFinishedin interface- BuildListener
- Parameters:
- event- the buildFinished event
- See Also:
 
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subBuildFinishedCleans up any resources held by this classloader at the end of a subbuild if it has been created for the subbuild's project instance.- Specified by:
- subBuildFinishedin interface- SubBuildListener
- Parameters:
- event- the buildFinished event
- Since:
- Ant 1.6.2
- See Also:
 
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subBuildStartedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- subBuildStartedin interface- SubBuildListener
- Parameters:
- event- the buildStarted event
- Since:
- Ant 1.6.2
 
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targetStartedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- targetStartedin interface- BuildListener
- Parameters:
- event- the targetStarted event
- See Also:
 
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targetFinishedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- targetFinishedin interface- BuildListener
- Parameters:
- event- the targetFinished event
- See Also:
 
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taskStartedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- taskStartedin interface- BuildListener
- Parameters:
- event- the taskStarted event
- See Also:
 
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taskFinishedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- taskFinishedin interface- BuildListener
- Parameters:
- event- the taskFinished event
- See Also:
 
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messageLoggedEmpty implementation to satisfy the BuildListener interface.- Specified by:
- messageLoggedin interface- BuildListener
- Parameters:
- event- the messageLogged event
- See Also:
 
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addJavaLibrariespublic void addJavaLibraries()add any libraries that come with different java versions here
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toString
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getResources- Overrides:
- getResourcesin class- ClassLoader
- Throws:
- IOException
 
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closepublic void close()- Specified by:
- closein interface- AutoCloseable
- Specified by:
- closein interface- Closeable
 
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newAntClassLoaderpublic static AntClassLoader newAntClassLoader(ClassLoader parent, Project project, Path path, boolean parentFirst) Factory method- Parameters:
- parent- ClassLoader
- project- Project
- path- Path
- parentFirst- boolean
- Returns:
- AntClassLoader
 
 
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