ClassEnhancerImpl (DataNucleus Core 4.1.17-SNAPSHOT API)

java.lang.Object
- org.datanucleus.enhancer.ClassEnhancerImpl

All Implemented Interfaces:

ClassEnhancer
```
public class ClassEnhancerImpl
extends Object
implements ClassEnhancer
```
Class enhancer using ASM (see http://asm.objectweb.org but included in DataNucleus core repackaged). ASM operates using a SAXParser-like "visitor-pattern". We utilise this as follows :-
- enhance : start with a ClassReader for the class to be enhanced, and create a EnhancerClassAdapter (attached to a ClassWriter) that will perform the modifications, and use that as a visitor for the reader so that the reader sends its events to the adapter. Within the EnhancerClassAdapter we also make use of a EnhancerMethodAdapter to update individual methods
- check : take a ClassReader, and create a EnhancerClassChecker that performs the checks. We then set the checker as a visitor for the reader so that the reader sends its events to the checker.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ClassEnhancerImpl.MyClassVisitor
Convenience class to look up the class name for a file.

Nested Classes
Modifier and Type	Class and Description
`static class`	`ClassEnhancerImpl.MyClassVisitor` Convenience class to look up the class name for a file.

Field Summary

Fields
Modifier and Type	Field and Description
`protected String`	`asmClassName` ASM Class name for this class (replace .
`protected byte[]`	`classBytes` Bytes of the class (after enhancing).
`protected String`	`classDescriptor` Class descriptor for this class.
`String`	`className` Class name of the class being enhanced
`protected ClassLoaderResolver`	`clr` Class Loader Resolver to use for any loading issues.
`protected Class`	`cls` Class that is being enhanced.
`protected ClassMetaData`	`cmd` MetaData for the class being enhanced.
`protected List<ClassField>`	`fieldsToAdd` List of fields to be added to the class.
`protected boolean`	`initialised` Flag for whether we are initialised.
`protected byte[]`	`inputBytes` Bytes of the input class (only when enhancing generated classes with no class file).
`protected String`	`inputResourceName` Resource name of the input class (only when the class exists in a class file).
`protected MetaDataManager`	`metaDataMgr` MetaData Manager to use.
`protected List<ClassMethod>`	`methodsToAdd` List of methods to be added to the class.
`protected EnhancementNamer`	`namer`
`protected Collection<String>`	`options` Options for enhancement.
`protected byte[]`	`pkClassBytes` Bytes for any auto-generated PK class (if generated during enhancement).
`protected boolean`	`update` Flag specifying if the class needs updating.

Fields inherited from interface org.datanucleus.enhancer.ClassEnhancer
ASM_API_VERSION, OPTION_GENERATE_DEFAULT_CONSTRUCTOR, OPTION_GENERATE_DETACH_LISTENER, OPTION_GENERATE_PK

Constructor Summary

Constructors
Constructor and Description
`ClassEnhancerImpl(ClassMetaData cmd, ClassLoaderResolver clr, MetaDataManager mmgr, EnhancementNamer namer)` Constructor for an enhancer for the class.
`ClassEnhancerImpl(ClassMetaData cmd, ClassLoaderResolver clr, MetaDataManager mmgr, EnhancementNamer namer, byte[] classBytes)` Constructor for an enhancer to enhance a class defined by the provided bytes.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected boolean`	`checkClassIsEnhanced(boolean logErrors)` Convenience method to return if a class is enhanced.
`boolean`	`enhance()` Method to enhance a classes definition.
`String`	`getASMClassName()` Accessor for the ASM class name
`Class`	`getClassBeingEnhanced()` Accessor for the class being enhanced.
`byte[]`	`getClassBytes()` Accessor for the class bytes.
`String`	`getClassDescriptor()` Accessor for the class descriptor for the class being enhanced
`ClassLoaderResolver`	`getClassLoaderResolver()` Accessor for the ClassLoaderResolver
`ClassMetaData`	`getClassMetaData()` Accessor for the ClassMetaData for the class.
`String`	`getClassName()` Accessor for the name of the class being enhanced.
`static String`	`getClassNameForFileName(String filename)` Convenience accessor for the class name that is stored in a particular class.
`List<ClassField>`	`getFieldsList()` Accessor for the fields required.
`MetaDataManager`	`getMetaDataManager()` Accessor for the MetaData manager in use.
`List<ClassMethod>`	`getMethodsList()` Accessor for the methods required.
`EnhancementNamer`	`getNamer()`
`byte[]`	`getPrimaryKeyClassBytes()` Accessor for the primary-key class bytes (if generating a PK).
`boolean`	`hasOption(String name)` Accessor for whether a particular option is enabled.
`protected void`	`initialise()` Initialisation of the information for enhancing this class.
`protected void`	`initialiseFieldsList()` Method to initialise the list of fields to add.
`protected void`	`initialiseMethodsList()` Method to initialise the list of methods to add.
`boolean`	`isPersistable(String className)` Check if the class is Persistable or is going to be enhanced based on the metadata
`protected boolean`	`requiresDetachable()` Convenience method for whether this class needs to implement Detachable
`void`	`save(String directoryName)` Method to save the class definition bytecode into a class file.
`void`	`setNamer(EnhancementNamer namer)`
`void`	`setOptions(Collection<String> options)` Method to set the options controlling the enhancement.
`boolean`	`validate()` Validate whether the class is enhanced.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - clr
```
protected final ClassLoaderResolver clr
```
    Class Loader Resolver to use for any loading issues.
  - metaDataMgr
```
protected final MetaDataManager metaDataMgr
```
    MetaData Manager to use.
  - cmd
```
protected final ClassMetaData cmd
```
    MetaData for the class being enhanced.
  - className
```
public final String className
```
    Class name of the class being enhanced
  - update
```
protected boolean update
```
    Flag specifying if the class needs updating.
  - fieldsToAdd
```
protected List<ClassField> fieldsToAdd
```
    List of fields to be added to the class.
  - methodsToAdd
```
protected List<ClassMethod> methodsToAdd
```
    List of methods to be added to the class.
  - initialised
```
protected boolean initialised
```
    Flag for whether we are initialised.
  - options
```
protected Collection<String> options
```
    Options for enhancement.
  - inputResourceName
```
protected String inputResourceName
```
    Resource name of the input class (only when the class exists in a class file).
  - inputBytes
```
protected byte[] inputBytes
```
    Bytes of the input class (only when enhancing generated classes with no class file).
  - cls
```
protected final Class cls
```
    Class that is being enhanced.
  - classBytes
```
protected byte[] classBytes
```
    Bytes of the class (after enhancing).
  - pkClassBytes
```
protected byte[] pkClassBytes
```
    Bytes for any auto-generated PK class (if generated during enhancement).
  - asmClassName
```
protected String asmClassName
```
    ASM Class name for this class (replace . with /).
  - classDescriptor
```
protected String classDescriptor
```
    Class descriptor for this class.
  - namer
```
protected EnhancementNamer namer
```
- Constructor Detail
  - ClassEnhancerImpl
```
public ClassEnhancerImpl(ClassMetaData cmd,
                         ClassLoaderResolver clr,
                         MetaDataManager mmgr,
                         EnhancementNamer namer)
```
    Constructor for an enhancer for the class. The class is assumed to be in the CLASSPATH.
    
    Parameters:
    
    cmd - MetaData for the class to be enhanced
    
    clr - ClassLoader resolver
    
    mmgr - MetaData manager
    
    namer - The namer
  - ClassEnhancerImpl
```
public ClassEnhancerImpl(ClassMetaData cmd,
                         ClassLoaderResolver clr,
                         MetaDataManager mmgr,
                         EnhancementNamer namer,
                         byte[] classBytes)
```
    Constructor for an enhancer to enhance a class defined by the provided bytes.
    
    Parameters:
    
    cmd - MetaData for the class to be enhanced
    
    clr - ClassLoader resolver
    
    mmgr - MetaData manager
    
    namer - The namer
    
    classBytes - Bytes of the class to enhance
- Method Detail
  - initialise
```
protected void initialise()
```
    Initialisation of the information for enhancing this class.
  - getClassName
```
public String getClassName()
```
    Description copied from interface: ClassEnhancer
    
    Accessor for the name of the class being enhanced.
    
    Specified by:
    
    getClassName in interface ClassEnhancer
    
    Returns:
    
    Class name
  - getMethodsList
```
public List<ClassMethod> getMethodsList()
```
    Accessor for the methods required.
    
    Specified by:
    
    getMethodsList in interface ClassEnhancer
    
    Returns:
    
    List of methods required for enhancement
  - getFieldsList
```
public List<ClassField> getFieldsList()
```
    Accessor for the fields required.
    
    Specified by:
    
    getFieldsList in interface ClassEnhancer
    
    Returns:
    
    List of fields required for enhancement
  - getClassLoaderResolver
```
public ClassLoaderResolver getClassLoaderResolver()
```
    Accessor for the ClassLoaderResolver
    
    Specified by:
    
    getClassLoaderResolver in interface ClassEnhancer
    
    Returns:
    
    ClassLoader resolver
  - getMetaDataManager
```
public MetaDataManager getMetaDataManager()
```
    Description copied from interface: ClassEnhancer
    
    Accessor for the MetaData manager in use.
    
    Specified by:
    
    getMetaDataManager in interface ClassEnhancer
    
    Returns:
    
    MetaData manager
  - getClassMetaData
```
public ClassMetaData getClassMetaData()
```
    Description copied from interface: ClassEnhancer
    
    Accessor for the ClassMetaData for the class.
    
    Specified by:
    
    getClassMetaData in interface ClassEnhancer
    
    Returns:
    
    MetaData for the class
  - requiresDetachable
```
protected boolean requiresDetachable()
```
    Convenience method for whether this class needs to implement Detachable
    
    Returns:
    
    Whether we need to implement the Detachable interface
  - isPersistable
```
public boolean isPersistable(String className)
```
    Check if the class is Persistable or is going to be enhanced based on the metadata
    
    Specified by:
    
    isPersistable in interface ClassEnhancer
    
    Parameters:
    
    className - the class name
    
    Returns:
    
    true if Persistable
  - setOptions
```
public void setOptions(Collection<String> options)
```
    Description copied from interface: ClassEnhancer
    
    Method to set the options controlling the enhancement.
    
    Specified by:
    
    setOptions in interface ClassEnhancer
    
    Parameters:
    
    options - The options
  - hasOption
```
public boolean hasOption(String name)
```
    Description copied from interface: ClassEnhancer
    
    Accessor for whether a particular option is enabled.
    
    Specified by:
    
    hasOption in interface ClassEnhancer
    
    Parameters:
    
    name - Name of the option
    
    Returns:
    
    Whether it has this option
  - save
```
public void save(String directoryName)
          throws IOException
```
    Method to save the class definition bytecode into a class file. If directoryName is specified it will be written to $directoryName/className.class else will overwrite the existing class.
    
    Specified by:
    
    save in interface ClassEnhancer
    
    Parameters:
    
    directoryName - Name of a directory (or null to overwrite the class)
    
    Throws:
    
    IOException - If an I/O error occurs in the write.
  - setNamer
```
public void setNamer(EnhancementNamer namer)
```
    Specified by:
    
    setNamer in interface ClassEnhancer
  - getClassNameForFileName
```
public static String getClassNameForFileName(String filename)
```
    Convenience accessor for the class name that is stored in a particular class.
    
    Parameters:
    
    filename - Name of the file
    
    Returns:
    
    The class name
  - getClassBeingEnhanced
```
public Class getClassBeingEnhanced()
```
    Accessor for the class being enhanced.
    
    Specified by:
    
    getClassBeingEnhanced in interface ClassEnhancer
    
    Returns:
    
    Class being enhanced
  - getASMClassName
```
public String getASMClassName()
```
    Accessor for the ASM class name
    
    Specified by:
    
    getASMClassName in interface ClassEnhancer
    
    Returns:
    
    ASM class name
  - getClassDescriptor
```
public String getClassDescriptor()
```
    Accessor for the class descriptor for the class being enhanced
    
    Specified by:
    
    getClassDescriptor in interface ClassEnhancer
    
    Returns:
    
    class descriptor
  - initialiseMethodsList
```
protected void initialiseMethodsList()
```
    Method to initialise the list of methods to add.
  - initialiseFieldsList
```
protected void initialiseFieldsList()
```
    Method to initialise the list of fields to add.
  - enhance
```
public boolean enhance()
```
    Method to enhance a classes definition.
    
    Specified by:
    
    enhance in interface ClassEnhancer
    
    Returns:
    
    Whether it was enhanced with no errors
  - getClassBytes
```
public byte[] getClassBytes()
```
    Accessor for the class bytes. Only has relevance to be called after enhance().
    
    Specified by:
    
    getClassBytes in interface ClassEnhancer
    
    Returns:
    
    The class bytes
  - getPrimaryKeyClassBytes
```
public byte[] getPrimaryKeyClassBytes()
```
    Accessor for the primary-key class bytes (if generating a PK). Only has relevance to be called after enhance().
    
    Specified by:
    
    getPrimaryKeyClassBytes in interface ClassEnhancer
    
    Returns:
    
    The primary-key class bytes
  - validate
```
public boolean validate()
```
    Description copied from interface: ClassEnhancer
    
    Validate whether the class is enhanced.
    
    Specified by:
    
    validate in interface ClassEnhancer
    
    Returns:
    
    Return true if already enhanced class.
  - checkClassIsEnhanced
```
protected boolean checkClassIsEnhanced(boolean logErrors)
```
    Convenience method to return if a class is enhanced.
    
    Parameters:
    
    logErrors - Whether to log any errors (missing methods etc) as errors (otherwise info/debug)
    
    Returns:
    
    Whether the class is enhanced
  - getNamer
```
public EnhancementNamer getNamer()
```
    Specified by:
    
    getNamer in interface ClassEnhancer

Class ClassEnhancerImpl

Nested Class Summary

Field Summary

Fields inherited from interface org.datanucleus.enhancer.ClassEnhancer

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

clr

metaDataMgr

cmd

className

update

fieldsToAdd

methodsToAdd

initialised

options

inputResourceName

inputBytes

cls

classBytes

pkClassBytes

asmClassName

classDescriptor

namer

Constructor Detail

ClassEnhancerImpl

ClassEnhancerImpl

Method Detail

initialise

getClassName

getMethodsList

getFieldsList

getClassLoaderResolver

getMetaDataManager

getClassMetaData

requiresDetachable

isPersistable

setOptions

hasOption

save

setNamer

getClassNameForFileName

getClassBeingEnhanced

getASMClassName

getClassDescriptor

initialiseMethodsList

initialiseFieldsList

enhance

getClassBytes

getPrimaryKeyClassBytes

validate

checkClassIsEnhanced

getNamer