Class ClasspathUtils
The basic idea behind this utility class is to use it from inside the different Ant objects (and user defined objects) that need classLoading for their operation. Normally those would have a setClasspathRef() {for the @classpathref} and/or a createClasspath() {for the nested <classpath>} Typically one would have in your Ant Task or DataType
 ClasspathUtils.Delegate cpDelegate;
 public void init() {
     this.cpDelegate = ClasspathUtils.getDelegate(this);
     super.init();
 }
 public void setClasspathRef(Reference r) {
     this.cpDelegate.setClasspathRef(r);
 }
 public Path createClasspath() {
     return this.cpDelegate.createClasspath();
 }
 public void setClassname(String fqcn) {
     this.cpDelegate.setClassname(fqcn);
 }
 At execution time, when you actually need the classloading you can just:
     Object o = this.cpDelegate.newInstance();
 - Since:
- Ant 1.6
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Nested Class SummaryNested ClassesModifier and TypeClassDescriptionstatic classDelegate that helps out any specific ProjectComponent that needs dynamic classloading.
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Field SummaryFieldsModifier and TypeFieldDescriptionstatic final StringName of the magic property that controls classloader reuse in Ant 1.4.
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Method SummaryModifier and TypeMethodDescriptionstatic ClassLoadergetClassLoaderForPath(Project p, Path path, String loaderId) Convenience overloaded version ofgetClassLoaderForPath(Project, Path, String, boolean).static ClassLoadergetClassLoaderForPath(Project p, Path path, String loaderId, boolean reverseLoader) Convenience overloaded version ofgetClassLoaderForPath(Project, Path, String, boolean, boolean).static ClassLoadergetClassLoaderForPath(Project p, Path path, String loaderId, boolean reverseLoader, boolean reuseLoader) Gets a classloader that loads classes from the classpath defined in the path argument.static ClassLoadergetClassLoaderForPath(Project p, Reference ref) Convenience overloaded version ofgetClassLoaderForPath(Project, Reference, boolean).static ClassLoadergetClassLoaderForPath(Project p, Reference ref, boolean reverseLoader) Convenience overloaded version ofgetClassLoaderForPath(Project, Path, String, boolean).static ClasspathUtils.DelegategetDelegate(ProjectComponent component) Obtains a delegate that helps out with classic classpath configuration.static ClassLoadergetUniqueClassLoaderForPath(Project p, Path path, boolean reverseLoader) Gets a fresh, different, previously unused classloader that uses the passed path as its classpath.static ObjectnewInstance(String className, ClassLoader userDefinedLoader) Creates a fresh object instance of the specified classname.static <T> TnewInstance(String className, ClassLoader userDefinedLoader, Class<T> expectedType) Creates a fresh object instance of the specified classname.
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Field Details- 
REUSE_LOADER_REFName of the magic property that controls classloader reuse in Ant 1.4.- See Also:
 
 
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Method Details- 
getClassLoaderForPathConvenience overloaded version ofgetClassLoaderForPath(Project, Reference, boolean).Assumes the logical 'false' for the reverseLoader. - Parameters:
- p- the project
- ref- the reference
- Returns:
- The class loader
 
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getClassLoaderForPathConvenience overloaded version ofgetClassLoaderForPath(Project, Path, String, boolean).Delegates to the other one after extracting the referenced Path from the Project. This checks also that the passed Reference is pointing to a Path all right. - Parameters:
- p- current Ant project
- ref- Reference to Path structure
- reverseLoader- if set to true this new loader will take precedence over its parent (which is contra the regular classloader behaviour)
- Returns:
- The class loader
 
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getClassLoaderForPathConvenience overloaded version ofgetClassLoaderForPath(Project, Path, String, boolean).Assumes the logical 'false' for the reverseLoader. - Parameters:
- p- current Ant project
- path- the path
- loaderId- the loader id string
- Returns:
- The class loader
 
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getClassLoaderForPathpublic static ClassLoader getClassLoaderForPath(Project p, Path path, String loaderId, boolean reverseLoader) Convenience overloaded version ofgetClassLoaderForPath(Project, Path, String, boolean, boolean).Sets value for 'reuseLoader' to true if the magic property has been set. - Parameters:
- p- the project
- path- the path
- loaderId- the loader id string
- reverseLoader- if set to true this new loader will take precedence over its parent (which is contra the regular classloader behaviour)
- Returns:
- The class loader
 
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getClassLoaderForPathpublic static ClassLoader getClassLoaderForPath(Project p, Path path, String loaderId, boolean reverseLoader, boolean reuseLoader) Gets a classloader that loads classes from the classpath defined in the path argument.Based on the setting of the magic property 'ant.reuse.loader' this will try to reuse the previously created loader with that id, and of course store it there upon creation. - Parameters:
- p- Ant Project where the handled components are living in.
- path- Path object to be used as classpath for this classloader
- loaderId- identification for this Loader,
- reverseLoader- if set to true this new loader will take precedence over its parent (which is contra the regular classloader behaviour)
- reuseLoader- if true reuse the loader if it is found
- Returns:
- ClassLoader that uses the Path as its classpath.
 
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getUniqueClassLoaderForPathGets a fresh, different, previously unused classloader that uses the passed path as its classpath.This method completely ignores the ant.reuse.loader magic property and should be used with caution. - Parameters:
- p- Ant Project where the handled components are living in.
- path- the classpath for this loader
- reverseLoader- if set to true this new loader will take precedence over its parent (which is contra the regular classloader behaviour)
- Returns:
- The fresh, different, previously unused class loader.
 
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newInstanceCreates a fresh object instance of the specified classname.This uses the userDefinedLoader to load the specified class, and then makes an instance using the default no-argument constructor. - Parameters:
- className- the full qualified class name to load.
- userDefinedLoader- the classloader to use.
- Returns:
- The fresh object instance
- Throws:
- BuildException- when loading or instantiation failed.
 
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newInstancepublic static <T> T newInstance(String className, ClassLoader userDefinedLoader, Class<T> expectedType) Creates a fresh object instance of the specified classname.This uses the userDefinedLoader to load the specified class, and then makes an instance using the default no-argument constructor. - Type Parameters:
- T- desired type
- Parameters:
- className- the full qualified class name to load.
- userDefinedLoader- the classloader to use.
- expectedType- the Class that the result should be assignment compatible with. (No ClassCastException will be thrown in case the result of this method is casted to the expectedType)
- Returns:
- The fresh object instance
- Throws:
- BuildException- when loading or instantiation failed.
- Since:
- Ant 1.7
 
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getDelegateObtains a delegate that helps out with classic classpath configuration.- Parameters:
- component- your projectComponent that needs the assistance
- Returns:
- the helper, delegate.
- See Also:
 
 
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