net.greghaines.jesque.utils

Class ReflectionUtils

java.lang.Object

net.greghaines.jesque.utils.ReflectionUtils

public final class ReflectionUtils
extends Object

Reflection utilities.

Author:

Greg Haines

Field Summary

Fields

Modifier and Type	Field and Description
static String	ARRAY_SUFFIX Suffix for array class names: "[]"

Method Summary

Modifier and Type	Method and Description
static <T> T	createObject(Class<T> clazz, Object... args) Create an object of the given type using a constructor that matches the supplied arguments.
static <T> T	createObject(Class<T> clazz, Object[] args, Map<String,Object> vars) Create an object of the given type using a constructor that matches the supplied arguments and invoke the setters with the supplied variables.
static Class<?>	forName(String name) Replacement for Class.forName() that also returns Class instances for primitives (like "int") and array class names (like "String[]").
static Class<?>	forName(String name, ClassLoader classLoader) Replacement for Class.forName() that also returns Class instances for primitives (e.g."int") and array class names (e.g.
static ClassLoader	getDefaultClassLoader() Return the default ClassLoader to use: typically the thread context ClassLoader, if available; the ClassLoader that loaded the ReflectionUtils class will be used as fallback.
static <T> T	invokeSetters(T instance, Map<String,Object> vars) Invoke the setters for the given variables on the given instance.
static boolean	isAssignable(Class<?> lhsType, Class<?> rhsType) Check if the right-hand side type may be assigned to the left-hand side type, assuming setting by reflection.
static boolean	isAssignableValue(Class<?> type, Object value) Determine if the given type is assignable from the given value, assuming setting by reflection.

Methods inherited from class java.lang.Object

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

Field Detail

ARRAY_SUFFIX

public static final String ARRAY_SUFFIX

Suffix for array class names: "[]"

See Also:

Constant Field Values

Method Detail

createObject

public static <T> T createObject(Class<T> clazz,
                                 Object... args)
                          throws NoSuchConstructorException,
                                 AmbiguousConstructorException,
                                 ReflectiveOperationException

Create an object of the given type using a constructor that matches the supplied arguments.

Type Parameters:

T - the object type

Parameters:

clazz - the type to create

args - the arguments to the constructor

Returns:

a new object of the given type, initialized with the given arguments

Throws:

NoSuchConstructorException - if there is not a constructor that matches the given arguments

AmbiguousConstructorException - if there is more than one constructor that matches the given arguments

ReflectiveOperationException - if any of the reflective operations throw an exception

createObject

public static <T> T createObject(Class<T> clazz,
                                 Object[] args,
                                 Map<String,Object> vars)
                          throws NoSuchConstructorException,
                                 AmbiguousConstructorException,
                                 ReflectiveOperationException

Create an object of the given type using a constructor that matches the supplied arguments and invoke the setters with the supplied variables.

Type Parameters:

T - the object type

Parameters:

clazz - the type to create

args - the arguments to the constructor

vars - the named arguments for setters

Returns:

a new object of the given type, initialized with the given arguments

Throws:

NoSuchConstructorException - if there is not a constructor that matches the given arguments

AmbiguousConstructorException - if there is more than one constructor that matches the given arguments

ReflectiveOperationException - if any of the reflective operations throw an exception

isAssignable

public static boolean isAssignable(Class<?> lhsType,
                                   Class<?> rhsType)

Check if the right-hand side type may be assigned to the left-hand side type, assuming setting by reflection. Considers primitive wrapper classes as assignable to the corresponding primitive types.

Parameters:

lhsType - the target type

rhsType - the value type that should be assigned to the target type

Returns:

if the target type is assignable from the value type

isAssignableValue

public static boolean isAssignableValue(Class<?> type,
                                        Object value)

Determine if the given type is assignable from the given value, assuming setting by reflection. Considers primitive wrapper classes as assignable to the corresponding primitive types.

Parameters:

type - the target type

value - the value that should be assigned to the type

Returns:

if the type is assignable from the value

getDefaultClassLoader

public static ClassLoader getDefaultClassLoader()

Return the default ClassLoader to use: typically the thread context ClassLoader, if available; the ClassLoader that loaded the ReflectionUtils class will be used as fallback.

Call this method if you intend to use the thread context ClassLoader in a scenario where you absolutely need a non-null ClassLoader reference: for example, for class path resource loading (but not necessarily for Class.forName, which accepts a null ClassLoader reference as well).

Returns:

the default ClassLoader (never null)

See Also:

Thread.getContextClassLoader()

forName

public static Class<?> forName(String name)
                        throws ClassNotFoundException

Replacement for Class.forName() that also returns Class instances for primitives (like "int") and array class names (like "String[]").

Always uses the default class loader: that is, preferably the thread context class loader, or the ClassLoader that loaded the ReflectionUtils class as fallback.

Parameters:

name - the name of the Class

Returns:

Class instance for the supplied name

Throws:

ClassNotFoundException - if the class was not found

See Also:

Class.forName(String, boolean, ClassLoader), getDefaultClassLoader()

forName

public static Class<?> forName(String name,
                               ClassLoader classLoader)
                        throws ClassNotFoundException

Replacement for Class.forName() that also returns Class instances for primitives (e.g."int") and array class names (e.g. "String[]"). Furthermore, it is also capable of resolving inner class names in Java source style (e.g. "java.lang.Thread.State" instead of "java.lang.Thread$State").

Parameters:

name - the name of the Class

classLoader - the class loader to use (may be null, which indicates the default class loader)

Returns:

Class instance for the supplied name

Throws:

ClassNotFoundException - if the class was not found

See Also:

Class.forName(String, boolean, ClassLoader)

invokeSetters

public static <T> T invokeSetters(T instance,
                                  Map<String,Object> vars)
                           throws ReflectiveOperationException

Invoke the setters for the given variables on the given instance.

Type Parameters:

T - the instance type

Parameters:

instance - the instance to inject with the variables

vars - the variables to inject

Returns:

the instance

Throws:

ReflectiveOperationException - if there was a problem finding or invoking a setter method