Package com.helger.commons.lang

Class GenericReflection

java.lang.Object

com.helger.commons.lang.GenericReflection

@Immutable
public final class GenericReflection
extends Object

This is a special helper class that provides many utility methods concerning the usage of reflection etc..

Author:

Philip Helger

Method Summary

Modifier and Type	Method	Description
static <DATATYPE> Constructor<DATATYPE>	findConstructor(DATATYPE aObj, Class<?>... aCtorArgs)
static Class<?>[]	getClassArray(Object... aObjs)	Get an array with all the classes of the passed object array.
static <DATATYPE> Class<DATATYPE>	getClassFromName(ClassLoader aClassLoader, String sName)
static <DATATYPE> Class<DATATYPE>	getClassFromName(String sName)
static <DATATYPE> Class<DATATYPE>	getClassFromNameSafe(ClassLoader aClassLoader, String sName)	Get the class of the given name
static <DATATYPE> Class<DATATYPE>	getClassFromNameSafe(String sName)	Get the class of the given name
static <RETURNTYPE> RETURNTYPE	invokeMethod(Object aSrcObj, String sMethodName, Class<?>[] aArgClasses, Object[] aArgs)
static <RETURNTYPE> RETURNTYPE	invokeMethod(Object aSrcObj, String sMethodName, Object... aArgs)	This method dynamically invokes the method with the given name on the given object.
static <RETURNTYPE> RETURNTYPE	invokeStaticMethod(Class<?> aClass, String sMethodName, Class<?>[] aArgClasses, Object[] aArgs)
static <RETURNTYPE> RETURNTYPE	invokeStaticMethod(Class<?> aClass, String sMethodName, Object... aArgs)
static <RETURNTYPE> RETURNTYPE	invokeStaticMethod(String sClassName, String sMethodName, Class<?>[] aArgClasses, Object[] aArgs)
static <RETURNTYPE> RETURNTYPE	invokeStaticMethod(String sClassName, String sMethodName, Object... aArgs)
static <DATATYPE> DATATYPE	newInstance(DATATYPE aObj)	Create a new instance of the class identified by the passed object.
static <DATATYPE> DATATYPE	newInstance(Class<? extends DATATYPE> aClass)
static <DATATYPE> DATATYPE	newInstance(ClassLoader aClassLoader, String sClassName, Class<? extends DATATYPE> aDesiredType)
static <DATATYPE> DATATYPE	newInstance(String sClassName, Class<? extends DATATYPE> aDesiredType)
static <DATATYPE> DATATYPE	newInstance(String sClassName, Class<? extends DATATYPE> aDesiredType, ClassLoader aClassLoaderToUse)
static <SRCTYPE,DSTTYPE> DSTTYPE	uncheckedCast(SRCTYPE aObject)

Methods inherited from class java.lang.Object

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

Method Detail

uncheckedCast

public static <SRCTYPE,DSTTYPE> DSTTYPE uncheckedCast(@Nullable
                                                            SRCTYPE aObject)

getClassFromName

@Nonnull
public static <DATATYPE> Class<DATATYPE> getClassFromName(@Nonnull
                                                          ClassLoader aClassLoader,
                                                          @Nonnull
                                                          String sName)
                                                   throws ClassNotFoundException

Throws:

ClassNotFoundException

getClassFromName

@Nonnull
public static <DATATYPE> Class<DATATYPE> getClassFromName(@Nonnull
                                                          String sName)
                                                   throws ClassNotFoundException

Throws:

ClassNotFoundException

getClassFromNameSafe

@Nullable
public static <DATATYPE> Class<DATATYPE> getClassFromNameSafe(@Nonnull
                                                              ClassLoader aClassLoader,
                                                              @Nonnull
                                                              String sName)

Get the class of the given name

Type Parameters:

DATATYPE - The return type

Parameters:

aClassLoader - The class loader to be used. May not be null.

sName - The name to be resolved.

Returns:

null if the class could not be resolved

getClassFromNameSafe

@Nullable
public static <DATATYPE> Class<DATATYPE> getClassFromNameSafe(@Nonnull
                                                              String sName)

Get the class of the given name

Type Parameters:

DATATYPE - The return type

Parameters:

sName - The name to be resolved.

Returns:

null if the class could not be resolved

getClassArray

@Nonnull
public static Class<?>[] getClassArray(@Nullable
                                       Object... aObjs)

Get an array with all the classes of the passed object array.

Parameters:

aObjs - The object array. May be null. No contained element may be null.

Returns:

A non-null array of classes.

invokeMethod

@Nullable
public static <RETURNTYPE> RETURNTYPE invokeMethod(@Nonnull
                                                   Object aSrcObj,
                                                   @Nonnull
                                                   String sMethodName,
                                                   @Nullable
                                                   Object... aArgs)
                                            throws NoSuchMethodException,
                                                   IllegalAccessException,
                                                   InvocationTargetException

This method dynamically invokes the method with the given name on the given object.

Type Parameters:

RETURNTYPE - The method return type

Parameters:

aSrcObj - The source object on which the method is to be invoked. May not be null.

sMethodName - The method to be invoked.

aArgs - The arguments to be passed into the method. May be null . If not null, the members of the array may not be null because otherwise the classes of the arguments cannot be determined and will throw an Exception!

Returns:

The return value of the invoked method or null for void methods.

Throws:

NoSuchMethodException - Thrown by reflection

IllegalAccessException - Thrown by reflection

InvocationTargetException - Thrown by reflection

invokeMethod

@Nullable
public static <RETURNTYPE> RETURNTYPE invokeMethod(@Nonnull
                                                   Object aSrcObj,
                                                   @Nonnull
                                                   String sMethodName,
                                                   @Nullable
                                                   Class<?>[] aArgClasses,
                                                   @Nullable
                                                   Object[] aArgs)
                                            throws NoSuchMethodException,
                                                   IllegalAccessException,
                                                   InvocationTargetException

Throws:

NoSuchMethodException

IllegalAccessException

InvocationTargetException

invokeStaticMethod

@Nullable
public static <RETURNTYPE> RETURNTYPE invokeStaticMethod(@Nonnull
                                                         String sClassName,
                                                         @Nonnull
                                                         String sMethodName,
                                                         @Nullable
                                                         Object... aArgs)
                                                  throws NoSuchMethodException,
                                                         IllegalAccessException,
                                                         InvocationTargetException,
                                                         ClassNotFoundException

Throws:

NoSuchMethodException

IllegalAccessException

InvocationTargetException

ClassNotFoundException

invokeStaticMethod

@Nullable
public static <RETURNTYPE> RETURNTYPE invokeStaticMethod(@Nonnull
                                                         Class<?> aClass,
                                                         @Nonnull
                                                         String sMethodName,
                                                         @Nullable
                                                         Object... aArgs)
                                                  throws NoSuchMethodException,
                                                         IllegalAccessException,
                                                         InvocationTargetException

Throws:

NoSuchMethodException

IllegalAccessException

InvocationTargetException

invokeStaticMethod

@Nullable
public static <RETURNTYPE> RETURNTYPE invokeStaticMethod(@Nonnull
                                                         String sClassName,
                                                         @Nonnull
                                                         String sMethodName,
                                                         @Nullable
                                                         Class<?>[] aArgClasses,
                                                         @Nullable
                                                         Object[] aArgs)
                                                  throws NoSuchMethodException,
                                                         IllegalAccessException,
                                                         InvocationTargetException,
                                                         ClassNotFoundException

Throws:

NoSuchMethodException

IllegalAccessException

InvocationTargetException

ClassNotFoundException

invokeStaticMethod

@Nullable
public static <RETURNTYPE> RETURNTYPE invokeStaticMethod(@Nonnull
                                                         Class<?> aClass,
                                                         @Nonnull
                                                         String sMethodName,
                                                         @Nullable
                                                         Class<?>[] aArgClasses,
                                                         @Nullable
                                                         Object[] aArgs)
                                                  throws NoSuchMethodException,
                                                         IllegalAccessException,
                                                         InvocationTargetException

Throws:

NoSuchMethodException

IllegalAccessException

InvocationTargetException

findConstructor

@Nonnull
public static <DATATYPE> Constructor<DATATYPE> findConstructor(@Nonnull
                                                               DATATYPE aObj,
                                                               Class<?>... aCtorArgs)
                                                        throws NoSuchMethodException

Throws:

NoSuchMethodException

newInstance

@Nonnull
public static <DATATYPE> DATATYPE newInstance(@Nonnull
                                              DATATYPE aObj)
                                       throws IllegalAccessException,
                                              NoSuchMethodException,
                                              InvocationTargetException,
                                              InstantiationException

Create a new instance of the class identified by the passed object. The default constructor will be invoked.

Type Parameters:

DATATYPE - The type of object to be created.

Parameters:

aObj - The object from which the class should be used.

Returns:

A new instance of the object or an exception is thrown.

Throws:

IllegalAccessException - Reflection exception

NoSuchMethodException - Reflection exception

InvocationTargetException - Reflection exception

InstantiationException - Reflection exception

newInstance

@Nullable
public static <DATATYPE> DATATYPE newInstance(@Nullable
                                              Class<? extends DATATYPE> aClass)

newInstance

@Nullable
public static <DATATYPE> DATATYPE newInstance(@Nonnull
                                              ClassLoader aClassLoader,
                                              @Nullable
                                              String sClassName,
                                              @Nullable
                                              Class<? extends DATATYPE> aDesiredType)

newInstance

@Nullable
public static <DATATYPE> DATATYPE newInstance(@Nullable
                                              String sClassName,
                                              @Nullable
                                              Class<? extends DATATYPE> aDesiredType)

newInstance

@Nullable
public static <DATATYPE> DATATYPE newInstance(@Nullable
                                              String sClassName,
                                              @Nullable
                                              Class<? extends DATATYPE> aDesiredType,
                                              @Nullable
                                              ClassLoader aClassLoaderToUse)