/**
* Creates an instance of the class using the default constructor.
*
* @since 0.2.06
*/
@SuppressWarnings("cast")
private static <T> T newInstanceFromDefaultConstructor(Class<T> type) {
if (type == null) return null;
if (logger.isDebugEnabled()) logger.debug("Instantiating " + type.getSimpleName());
if (deprecated(type))
escalator.escalate(
"Instantiating a deprecated class: " + type.getName(), BeanUtil.class, null);
try {
return (T) type.newInstance();
} catch (InstantiationException e) {
throw ExceptionMapper.configurationException(e, type);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, type);
}
}
/**
* Returns the bean property descriptor of an attribute
*
* @param beanClass the class that holds the attribute
* @param propertyName the name of the property
* @return the attribute's property descriptor
*/
public static PropertyDescriptor getPropertyDescriptor(Class<?> beanClass, String propertyName) {
if (beanClass == null) throw new IllegalArgumentException("beanClass is null");
String propertyId = beanClass.getName() + '#' + propertyName;
PropertyDescriptor result = propertyDescriptors.get(propertyId);
if (result != null) return result;
// descriptor is new
int separatorIndex = propertyName.indexOf('.');
if (separatorIndex >= 0) {
String localProperty = propertyName.substring(0, separatorIndex);
String remoteProperty = propertyName.substring(separatorIndex + 1);
Class<?> localPropertyType =
getPropertyDescriptor(beanClass, localProperty).getPropertyType();
result = getPropertyDescriptor(localPropertyType, remoteProperty);
} else {
try {
BeanInfo beanInfo = Introspector.getBeanInfo(beanClass);
PropertyDescriptor[] descriptors = beanInfo.getPropertyDescriptors();
for (PropertyDescriptor descriptor : descriptors) {
String name = descriptor.getName();
if (name.equals(propertyName)) {
result = descriptor;
break;
}
}
} catch (IntrospectionException e) {
throw ExceptionMapper.configurationException(e, propertyName);
}
}
propertyDescriptors.put(propertyId, result);
return result;
}
/**
* Instantiates the specified class.
*
* @param name the name of the class to instantiate
* @return the Class instance
*/
@SuppressWarnings({"unchecked", "rawtypes"})
public static <T> Class<T> forName(String name) {
Assert.notNull(name, "class name");
Class type = simpleTypeMap.get(name);
if (type != null) return type;
else {
try {
return (Class<T>) getContextClassLoader().loadClass(name);
} catch (ClassNotFoundException e) {
throw ExceptionMapper.configurationException(e, name);
} catch (NullPointerException e) {
// this is raised by the Eclipse BundleLoader if it does not find the class
throw ExceptionMapper.configurationException(e, name);
}
}
}
/**
* Sets an attribute value of an object.
*
* @param obj the object to modify
* @param field the attribute to set
* @param value the value to assign to the field
*/
private static void setAttributeValue(Object obj, Field field, Object value) {
try {
field.set(obj, value);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, field);
}
}
/**
* Returns a Field object that represents an attribute of a class
*
* @param type the class that holds the attribute
* @param name the name of the attribute
* @return a Field object that represents the attribute
*/
public static Field getField(Class<?> type, String name) {
try {
return type.getField(name);
} catch (NoSuchFieldException e) {
throw ExceptionMapper.configurationException(e, type.getName() + '.' + name);
}
}
public static <T> T newInstance(
Constructor<T> constructor, boolean strict, Object... parameters) {
if (!strict) parameters = convertArray(parameters, constructor.getParameterTypes());
Class<T> type = constructor.getDeclaringClass();
if (deprecated(type))
escalator.escalate(
"Instantiating a deprecated class: " + type.getName(), BeanUtil.class, null);
try {
return constructor.newInstance(parameters);
} catch (InstantiationException e) {
throw ExceptionMapper.configurationException(e, type);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, type);
} catch (InvocationTargetException e) {
throw ExceptionMapper.configurationException(e, type);
}
}
/**
* Returns a class' static attribute value
*
* @param objectType the class to query
* @param attributeName the name of the attribute
* @return the attribute value
*/
public static Object getStaticAttributeValue(Class<?> objectType, String attributeName) {
Field field = getField(objectType, attributeName);
try {
return field.get(null);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, field);
}
}
@SuppressWarnings({"unchecked", "rawtypes"})
public static Object invoke(Object target, Method method, boolean strict, Object... args) {
try {
Object[] params;
Class<?>[] paramTypes = method.getParameterTypes();
if (paramTypes.length == 0) {
params = null;
} else if (args.length == paramTypes.length) {
// map one to one
if (strict) {
params = args;
} else {
params = new Object[paramTypes.length];
for (int i = 0; i < paramTypes.length; i++) {
Object arg = args[i];
if (arg == null) params[i] = null;
else {
Converter converter =
ConverterManager.getInstance().createConverter(arg.getClass(), paramTypes[i]);
params[i] = converter.convert(arg);
}
}
}
} else {
// map varargs
params = new Object[paramTypes.length];
for (int i = 0; i < paramTypes.length - 1; i++)
params[i] = (strict ? args[i] : AnyConverter.convert(args[i], paramTypes[i]));
Class<?> varargsComponentType = paramTypes[paramTypes.length - 1].getComponentType();
Object varargs =
Array.newInstance(varargsComponentType, args.length - paramTypes.length + 1);
for (int i = 0; i < args.length - paramTypes.length + 1; i++) {
Object param = args[paramTypes.length - 1 + i];
if (strict) param = AnyConverter.convert(param, varargsComponentType);
Array.set(varargs, i, param);
}
params[params.length - 1] = varargs;
}
return method.invoke(target, params);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, method);
} catch (InvocationTargetException e) {
throw ExceptionMapper.configurationException(e, method);
}
}
public static Object getPropertyValue(Object bean, String propertyName, boolean strict) {
Method readMethod = null;
try {
PropertyDescriptor descriptor = getPropertyDescriptor(bean.getClass(), propertyName);
if (descriptor == null) {
if (strict)
throw new ConfigurationError(
"Property '" + propertyName + "' not found in class " + bean.getClass());
else return null;
}
readMethod = descriptor.getReadMethod();
return readMethod.invoke(bean);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, readMethod);
} catch (InvocationTargetException e) {
throw ExceptionMapper.configurationException(e, readMethod);
}
}
/**
* Returns an object's attribute value
*
* @param obj the object to query
* @param attributeName the name of the attribute
* @return the attribute value
*/
public static Object getAttributeValue(Object obj, String attributeName) {
if (obj == null) throw new IllegalArgumentException("Object may not be null");
Field field = getField(obj.getClass(), attributeName);
try {
return field.get(obj);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, field);
}
}
public static void setPropertyValue(
Object bean,
String propertyName,
Object propertyValue,
boolean required,
boolean autoConvert) {
Method writeMethod = null;
try {
Class<?> beanClass = bean.getClass();
PropertyDescriptor propertyDescriptor = getPropertyDescriptor(beanClass, propertyName);
if (propertyDescriptor == null)
if (required)
throw new ConfigurationError(
beanClass + " does not have a property '" + propertyName + "'");
else return;
writeMethod = propertyDescriptor.getWriteMethod();
if (writeMethod == null)
throw new UnsupportedOperationException(
"Cannot write read-only property '"
+ propertyDescriptor.getName()
+ "' of "
+ beanClass);
Class<?> propertyType = propertyDescriptor.getPropertyType();
if (propertyValue != null) {
Class<?> argType = propertyValue.getClass();
if (!propertyType.isAssignableFrom(argType)
&& !isWrapperTypeOf(propertyType, propertyValue)
&& !autoConvert)
throw new IllegalArgumentException(
"ArgumentType mismatch: expected "
+ propertyType.getName()
+ ", found "
+ propertyValue.getClass().getName());
else propertyValue = AnyConverter.convert(propertyValue, propertyType);
}
writeMethod.invoke(bean, propertyValue);
} catch (IllegalAccessException e) {
throw ExceptionMapper.configurationException(e, writeMethod);
} catch (InvocationTargetException e) {
throw ExceptionMapper.configurationException(e, writeMethod);
}
}
public static Object getFieldValue(Object target, String name, boolean strict) {
Class<?> type = target.getClass();
try {
Field field = type.getField(name);
return getFieldValue(field, target, strict);
} catch (NoSuchFieldException e) {
if (strict) throw ExceptionMapper.configurationException(e, type.getName() + '.' + name);
else {
escalator.escalate("Class '" + type + "' does not have a field '" + name + "'", type, name);
return null;
}
}
}
@SuppressWarnings({"unchecked", "rawtypes"})
public static <T> T newInstance(Class<T> type, boolean strict, Object... parameters) {
if (parameters.length == 0) return newInstanceFromDefaultConstructor(type);
Constructor<T> constructorToUse = null;
try {
Constructor<T>[] constructors = (Constructor<T>[]) type.getConstructors();
List<Constructor<T>> candidates = new ArrayList<Constructor<T>>(constructors.length);
int paramCount = parameters.length;
for (Constructor<T> constructor : constructors)
if (constructor.getParameterTypes().length == paramCount) candidates.add(constructor);
if (candidates.size() == 1) constructorToUse = candidates.get(0);
else if (candidates.size() == 0)
throw new ConfigurationError(
"No constructor with " + paramCount + " parameters found for " + type);
else {
// there are several candidates - find the first one with matching types
Class<?>[] paramTypes = new Class[parameters.length];
for (int i = 0; i < parameters.length; i++) paramTypes[i] = parameters[i].getClass();
for (Constructor c : type.getConstructors()) {
if (typesMatch(c.getParameterTypes(), paramTypes)) {
constructorToUse = c;
break;
}
}
// there is no ideal match
if (constructorToUse == null) {
if (strict)
throw new NoSuchMethodException(
"No appropriate constructor found: "
+ type
+ '('
+ ArrayFormat.format(", ", paramTypes)
+ ')');
Exception mostRecentException = null;
for (Constructor<T> candidate : candidates) {
try {
return newInstance(candidate, strict, parameters);
} catch (Exception e) {
mostRecentException = e;
logger.warn("Exception in constructor call: " + candidate, e);
continue; // ignore exception and try next constructor
}
}
// no constructor could be called without exception
String errMsg =
(mostRecentException != null
? "None of these constructors could be called without exception: "
+ candidates
+ ", latest exception: "
+ mostRecentException
: type
+ " has no appropriate constructor for the arguments "
+ ArrayFormat.format(", ", parameters));
throw new ConfigurationError(errMsg);
}
}
if (!strict) parameters = convertArray(parameters, constructorToUse.getParameterTypes());
return newInstance(constructorToUse, parameters);
} catch (SecurityException e) {
throw ExceptionMapper.configurationException(e, constructorToUse);
} catch (NoSuchMethodException e) {
throw ExceptionMapper.configurationException(e, type);
}
}
