GroovyClassLoader (groovy 2.4.9 API)
Date: 2017-02-24

Package: groovy.lang

## [Java] Class GroovyClassLoader

- groovy.lang.GroovyClassLoader

- A ClassLoader which can load Groovy classes. The loaded classes are cached, classes from other classloaders should not be cached. To be able to load a script that was asked for earlier but was created later it is essential not to keep anything like a "class not found" information for that class name. This includes possible parent loaders. Classes that are not cached are always reloaded.

  Authors:
    James Strachan
    Guillaume Laforge
    Steve Goetze
    Bing Ran
    Scott Stirling
    Jochen Theodorou

- - ### Nested Class Summary

    Nested classes
    Modifiers | Name | Description
    --- | --- | ---
    `static class` | `GroovyClassLoader.ClassCollector` |
    `static class` | `GroovyClassLoader.InnerLoader` |

  - ### Field Summary

    Fields
    Modifiers | Name | Description
    --- | --- | ---
    `protected Map<String, Class>` | `classCache` | this cache contains the loaded classes or PARSING, if the class is currently parsed
    `protected Map<String, Class>` | `sourceCache` | This cache contains mappings of file name to class.

  - ### Constructor Summary

    Constructors
    Constructor and description
    `GroovyClassLoader ()` creates a GroovyClassLoader using the current Thread's context Class loader as parent.
    `GroovyClassLoader (ClassLoader loader)` creates a GroovyClassLoader using the given ClassLoader as parent
    `GroovyClassLoader (GroovyClassLoader parent)` creates a GroovyClassLoader using the given GroovyClassLoader as parent.
    `GroovyClassLoader (ClassLoader parent, CompilerConfiguration config, boolean useConfigurationClasspath)` creates a GroovyClassLoader.
    `GroovyClassLoader (ClassLoader loader, CompilerConfiguration config)` creates a GroovyClassLoader using the given ClassLoader as parent.

  - ### Methods Summary

    Methods
    Type Params | Return Type | Name and description
    --- | --- | ---
    `` | `void` | `addClasspath(String path)` adds a classpath to this classloader.
    `` | `void` | `addURL(URL url)` adds a URL to the classloader.
    `` | `void` | `clearCache()` Removes all classes from the class cache.
    `` | `protected GroovyClassLoader.ClassCollector` | `createCollector(CompilationUnit unit, SourceUnit su)` creates a ClassCollector for a new compilation.
    `` | `protected CompilationUnit` | `createCompilationUnit(CompilerConfiguration config, CodeSource source)` creates a new CompilationUnit.
    `` | `Class` | `defineClass(ClassNode classNode, String file, String newCodeBase)` Loads the given class node returning the implementation Class.
    `` | `Class` | `defineClass(String name, byte[] b)` open up the super class define that takes raw bytes
    `` | `String` | `generateScriptName()`
    `` | `protected Class` | `getClassCacheEntry(String name)` gets a class from the class cache.
    `` | `protected String[]` | `getClassPath()` gets the currently used classpath.
    `` | `Class[]` | `getLoadedClasses()`
    `` | `protected PermissionCollection` | `getPermissions(CodeSource codeSource)`
    `` | `GroovyResourceLoader` | `getResourceLoader()`
    `` | `protected long` | `getTimeStamp(Class cls)` gets the time stamp of a given class.
    `` | `protected boolean` | `isRecompilable(Class cls)` Indicates if a class is recompilable.
    `` | `Boolean` | `isShouldRecompile()` gets the currently set recompilation mode. null means, the compiler configuration is used.
    `` | `protected boolean` | `isSourceNewer(URL source, Class cls)` Decides if the given source is newer than a class.
    `` | `Class` | `loadClass(String name, boolean lookupScriptFiles, boolean preferClassOverScript)` loads a class from a file or a parent classloader.
    `` | `Class` | `loadClass(String name, boolean lookupScriptFiles, boolean preferClassOverScript, boolean resolve)` loads a class from a file or a parent classloader.
    `` | `Class<?>` | `loadClass(String name)`
    `` | `protected Class` | `loadClass(String name, boolean resolve)` Implemented here to check package access prior to returning an already loaded class.
    `` | `Class` | `parseClass(File file)` Parses the given file into a Java class capable of being run
    `` | `Class` | `parseClass(String text, String fileName)` Parses the given text into a Java class capable of being run
    `` | `Class` | `parseClass(String text)` Parses the given text into a Java class capable of being run
    `` | `Class` | `parseClass(InputStream in, String fileName)` @deprecated Prefer using methods taking a Reader rather than an InputStream to avoid wrong encoding issues.
    `` | `Class` | `parseClass(GroovyCodeSource codeSource)`
    `` | `Class` | `parseClass(GroovyCodeSource codeSource, boolean shouldCacheSource)` Parses the given code source into a Java class.
    `` | `protected Class` | `recompile(URL source, String className, Class oldClass)` (Re)Compiles the given source.
    `` | `protected void` | `removeClassCacheEntry(String name)` removes a class from the class cache.
    `` | `protected void` | `setClassCacheEntry(Class cls)` sets an entry in the class cache.
    `` | `void` | `setResourceLoader(GroovyResourceLoader resourceLoader)`
    `` | `void` | `setShouldRecompile(Boolean mode)` sets if the recompilation should be enable.

  - ### Inherited Methods Summary

    Inherited Methods
    Methods inherited from class | Name
    --- | ---
    `class URLClassLoader` | `getResourceAsStream, newInstance, newInstance, findResource, findResources, close, getURLs, loadClass, getSystemClassLoader, getResource, getSystemResource, getSystemResourceAsStream, clearAssertionStatus, getParent, getResources, getSystemResources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, wait, wait, wait, equals, toString, hashCode, getClass, notify, notifyAll`
    `class SecureClassLoader` | `loadClass, getSystemClassLoader, getResource, getResourceAsStream, getSystemResource, getSystemResourceAsStream, clearAssertionStatus, getParent, getResources, getSystemResources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, wait, wait, wait, equals, toString, hashCode, getClass, notify, notifyAll`

- - ### Field Detail

    - #### protected final Map<String, Class> classCache

      this cache contains the loaded classes or PARSING, if the class is currently parsed

    - #### protected final Map<String, Class> sourceCache

      This cache contains mappings of file name to class. It is used to bypass compilation.

  - ### Constructor Detail

    - #### public GroovyClassLoader()

      creates a GroovyClassLoader using the current Thread's context Class loader as parent.

    - #### public GroovyClassLoader(ClassLoader loader)

      creates a GroovyClassLoader using the given ClassLoader as parent

    - #### public GroovyClassLoader(GroovyClassLoader parent)

      creates a GroovyClassLoader using the given GroovyClassLoader as parent. This loader will get the parent's CompilerConfiguration

    - #### public GroovyClassLoader(ClassLoader parent, CompilerConfiguration config, boolean useConfigurationClasspath)

      creates a GroovyClassLoader.

      Parameters:
        `parent` - the parent class loader
        `config` - the compiler configuration
        `useConfigurationClasspath` - determines if the configurations classpath should be added

    - #### public GroovyClassLoader(ClassLoader loader, CompilerConfiguration config)

      creates a GroovyClassLoader using the given ClassLoader as parent.

  - ### Method Detail

    - #### public void addClasspath(String path)

      adds a classpath to this classloader.

      Parameters:
        `path` - is a jar file or a directory.
      See Also:
        addURL(URL)

    - #### public void addURL(URL url)

      adds a URL to the classloader.

      Parameters:
        `url` - the new classpath element

    - #### public void clearCache()

      Removes all classes from the class cache.

      See Also:
        getClassCacheEntry(String)
        setClassCacheEntry(Class)
        removeClassCacheEntry(String)

    - #### protected GroovyClassLoader.ClassCollector createCollector(CompilationUnit unit, SourceUnit su)

      creates a ClassCollector for a new compilation.

      Returns:
        the ClassCollector
      Parameters:
        `unit` - the compilationUnit
        `su` - the SourceUnit

    - #### protected CompilationUnit createCompilationUnit(CompilerConfiguration config, CodeSource source)

      creates a new CompilationUnit. If you want to add additional phase operations to the CompilationUnit (for example to inject additional methods, variables, fields), then you should overwrite this method.

      Returns:
        the CompilationUnit
      Parameters:
        `config` - the compiler configuration, usually the same as for this class loader
        `source` - the source containing the initial file to compile, more files may follow during compilation

    - #### public Class defineClass(ClassNode classNode, String file, String newCodeBase)

      Loads the given class node returning the implementation Class.

      WARNING: this compilation is not synchronized

      Returns:
        a class
      Parameters:
        classNode

    - #### public Class defineClass(String name, byte[] b)

      open up the super class define that takes raw bytes

    - #### public String generateScriptName()

    - #### protected Class getClassCacheEntry(String name)

      gets a class from the class cache. This cache contains only classes loaded through this class loader or an InnerLoader instance. If no class is stored for a specific name, then the method should return null.

      Returns:
        the class stored for the given name
      Parameters:
        `name` - of the class
      See Also:
        removeClassCacheEntry(String)
        setClassCacheEntry(Class)
        clearCache()

    - #### protected String[] getClassPath()

      gets the currently used classpath.

      Returns:
        a String[] containing the file information of the urls
      See Also:
        getURLs()

    - #### public Class[] getLoadedClasses()

      Returns all Groovy classes loaded by this class loader.

      Returns:
        all classes loaded by this class loader

    - #### protected PermissionCollection getPermissions(CodeSource codeSource)

    - #### public GroovyResourceLoader getResourceLoader()

    - #### protected long getTimeStamp(Class cls)

      gets the time stamp of a given class. For groovy generated classes this usually means to return the value of the static field __timeStamp. If the parameter doesn't have such a field, then Long.MAX_VALUE is returned

      Returns:
        the time stamp
      Parameters:
        `cls` - the class

    - #### protected boolean isRecompilable(Class cls)

      Indicates if a class is recompilable. Recompilable means, that the classloader will try to locate a groovy source file for this class and then compile it again, adding the resulting class as entry to the cache. Giving null as class is like a recompilation, so the method should always return true here. Only classes that are implementing GroovyObject are compilable and only if the timestamp in the class is lower than Long.MAX_VALUE.

      NOTE: First the parent loaders will be asked and only if they don't return a class the recompilation will happen. Recompilation also only happen if the source file is newer.

      Returns:
        true if the class should be compiled again
      Parameters:
        `cls` - the class to be tested. If null the method should return true
      See Also:
        isSourceNewer(URL, Class)

    - #### public Boolean isShouldRecompile()

      gets the currently set recompilation mode. null means, the compiler configuration is used. False means no recompilation and true means that recompilation will be done if needed.

      Returns:
        the recompilation mode

    - #### protected boolean isSourceNewer(URL source, Class cls)

      Decides if the given source is newer than a class.

      throws:
        IOException if it is not possible to open an connection for the given source
      Returns:
        true if the source is newer, false else
      Parameters:
        `source` - the source we may want to compile
        `cls` - the former class
      See Also:
        getTimeStamp(Class)

    - #### public Class loadClass(String name, boolean lookupScriptFiles, boolean preferClassOverScript)

      loads a class from a file or a parent classloader. This method does call loadClass(String, boolean, boolean, boolean) with the last parameter set to false.

      throws:
        CompilationFailedException if compilation was not successful

    - #### public Class loadClass(String name, boolean lookupScriptFiles, boolean preferClassOverScript, boolean resolve)

      loads a class from a file or a parent classloader.

      throws:
        ClassNotFoundException if the class could not be found
      throws:
        CompilationFailedException if the source file could not be compiled
      Returns:
        the class found or the class created from a file lookup
      Parameters:
        `name` - of the class to be loaded
        `lookupScriptFiles` - if false no lookup at files is done at all
        `preferClassOverScript` - if true the file lookup is only done if there is no class
        `resolve` - see ClassLoader.loadClass

    - #### @Override public Class<?> loadClass(String name)

    - #### protected Class loadClass(String name, boolean resolve)

      Implemented here to check package access prior to returning an already loaded class.

      throws:
        CompilationFailedException if the compilation failed
      throws:
        ClassNotFoundException if the class was not found
      See Also:
        ClassLoader.loadClass

    - #### public Class parseClass(File file)

      Parses the given file into a Java class capable of being run

      Returns:
        the main class defined in the given script
      Parameters:
        `file` - the file name to parse

    - #### public Class parseClass(String text, String fileName)

      Parses the given text into a Java class capable of being run

      Returns:
        the main class defined in the given script
      Parameters:
        `text` - the text of the script/class to parse
        `fileName` - the file name to use as the name of the class

    - #### public Class parseClass(String text)

      Parses the given text into a Java class capable of being run

      Returns:
        the main class defined in the given script
      Parameters:
        `text` - the text of the script/class to parse

    - #### @Deprecated public Class parseClass(InputStream in, String fileName)

      deprecated:
        Prefer using methods taking a Reader rather than an InputStream to avoid wrong encoding issues.

    - #### public Class parseClass(GroovyCodeSource codeSource)

    - #### public Class parseClass(GroovyCodeSource codeSource, boolean shouldCacheSource)

      Parses the given code source into a Java class. If there is a class file for the given code source, then no parsing is done, instead the cached class is returned.

      Returns:
        the main class defined in the given script
      Parameters:
        `shouldCacheSource` - if true then the generated class will be stored in the source cache

    - #### protected Class recompile(URL source, String className, Class oldClass)

      (Re)Compiles the given source. This method starts the compilation of a given source, if the source has changed since the class was created. For this isSourceNewer is called.

      throws:
        CompilationFailedException if the compilation failed
      throws:
        IOException if the source is not readable
      Returns:
        the old class if the source wasn't new enough, the new class else
      Parameters:
        `source` - the source pointer for the compilation
        `className` - the name of the class to be generated
        `oldClass` - a possible former class
      See Also:
        isSourceNewer(URL, Class)

    - #### protected void removeClassCacheEntry(String name)

      removes a class from the class cache.

      Parameters:
        `name` - of the class
      See Also:
        getClassCacheEntry(String)
        setClassCacheEntry(Class)
        clearCache()

    - #### protected void setClassCacheEntry(Class cls)

      sets an entry in the class cache.

      Parameters:
        `cls` - the class
      See Also:
        removeClassCacheEntry(String)
        getClassCacheEntry(String)
        clearCache()

    - #### public void setResourceLoader(GroovyResourceLoader resourceLoader)

    - #### public void setShouldRecompile(Boolean mode)

      sets if the recompilation should be enable. There are 3 possible values for this. Any value different than null overrides the value from the compiler configuration. true means to recompile if needed false means to never recompile.

      Parameters:
        `mode` - the recompilation mode
      See Also:
        CompilerConfiguration