sirius.kernel.commons

Class Reflection

java.lang.Object

sirius.kernel.commons.Reflection

public class Reflection
extends Object

Helper class for generic reflection tasks.

Method Summary

Modifier and Type	Method and Description
static Object	evalAccessPath(String path, Object root) Evaluates the given access path (dot separated getters) and returns the result.
static List<Field>	getAllFields(Class<?> clazz) Returns all fields defined by this class or one of its superclasses.
static Method	getter(Class<?> clazz, String property) Returns the getter method according to the java beans specification for a given property.
static boolean	isSubclassOf(Class<?> superclass, Class<?> classInQuestion) Determines if the given superclass is the same or a superclass or superinterface of the given classInQuestion.
static Method	setter(Class<?> clazz, String property, Class<?> fieldType) Returns the setter method according to the java beans specification for a given property.
static String	toFirstUpper(String string) Converts the first character of a given string to upper case.
static void	walkHierarchy(Class<?> clazz, Callback<Class<?>> handler) Calls the given handler for each superclass of the given one.

Methods inherited from class java.lang.Object

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

Method Detail

toFirstUpper

@Nullable
public static String toFirstUpper(@Nullable
                                            String string)

Converts the first character of a given string to upper case.

Comes in handy when translating properties to getter/setter names.

Parameters:

string - the name of the property to convert

Returns:

the given string, with an upper-case letter at the start or null if the input was null

getter

@Nonnull
public static Method getter(@Nonnull
                                     Class<?> clazz,
                                     @Nonnull
                                     String property)

Returns the getter method according to the java beans specification for a given property.

Parameters:

clazz - the class in which the method should be searched

property - the name of the property for which the getter is requested

Returns:

the Method which is used to get the value

Throws:

IllegalArgumentException - if the getter cannot be obtained

setter

public static Method setter(Class<?> clazz,
                            String property,
                            Class<?> fieldType)

Returns the setter method according to the java beans specification for a given property.

Parameters:

clazz - the class in which the method should be searched

property - the name of the property for which the setter is requested

fieldType - determines the type of the field (which is accepted as parameter of the setter)

Returns:

the Method which is used to get the value

Throws:

IllegalArgumentException - if the setter cannot be obtained

evalAccessPath

public static Object evalAccessPath(String path,
                                    Object root)

Evaluates the given access path (dot separated getters) and returns the result.

An access path can look like foo.bar.baz and represents: root.getFoo().getBar().getBaz(). If any of the getters returns null, null will also be the result of the evaluation.

Parameters:

path - the access path to evaluate

root - the root object on which the first getter is called

Returns:

the result of the last getter

walkHierarchy

public static void walkHierarchy(@Nonnull
                                 Class<?> clazz,
                                 @Nonnull
                                 Callback<Class<?>> handler)
                          throws Exception

Calls the given handler for each superclass of the given one.

Calls the handler for the given class and each of its superclasses until Object is reached.

Parameters:

clazz - the class to start from

handler - the handler to call for each superclass

Throws:

Exception - thrown if the handler throws an exception

getAllFields

@Nonnull
public static List<Field> getAllFields(@Nonnull
                                                Class<?> clazz)

Returns all fields defined by this class or one of its superclasses. This includes public, protected and private fields.

Parameters:

clazz - the class to collect the fields for

Returns:

a list of all defined fields of the given class and its superclasses (excluding Object)

isSubclassOf

public static boolean isSubclassOf(@Nonnull
                                   Class<?> superclass,
                                   @Nonnull
                                   Class<?> classInQuestion)

Determines if the given superclass is the same or a superclass or superinterface of the given classInQuestion.

This is essentially a shortcut for superclass.isAssignableFrom(classInQuestion) which seems to be more natural.

Parameters:

superclass - the designated superclass or superinterface

classInQuestion - the class in question

Returns:

true if the class in question is the same, a subclass or subinterface of the given superclass.