BeanUtils.java

package org.theonefx.wcframework.utils;

import java.beans.PropertyDescriptor;
import java.beans.PropertyEditor;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.URI;
import java.net.URL;
import java.util.Arrays;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.WeakHashMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.theonefx.wcframework.core.exception.BeansException;
import org.theonefx.wcframework.core.exception.FatalBeanException;
import org.theonefx.wcframework.ioc.BeanWrapper;
import org.theonefx.wcframework.ioc.CachedIntrospectionResults;
import org.theonefx.wcframework.ioc.exception.BeanInstantiationException;
import org.theonefx.wcframework.ioc.val.MethodParameter;

/**
 * Static convenience methods for JavaBeans: for instantiating beans, checking
 * bean property types, copying bean properties, etc.
 * 
 * <p>
 * Mainly for use within the framework, but to some degree also useful for
 * application classes.
 */
public abstract class BeanUtils {

	private static final Log log = LogFactory.getLog(BeanUtils.class);

	private static final Map<Class<?>, Boolean> unknownEditorTypes = Collections.synchronizedMap(new WeakHashMap<Class<?>, Boolean>());

	public static String getClassSimpleName(String name){
		String id = name.substring(0,1).toLowerCase()+name.substring(1);
		return id;
	}
	
	/**
	 * Convenience method to instantiate a class using its no-arg constructor.
	 * As this method doesn't try to load classes by name, it should avoid
	 * class-loading issues.
	 * 
	 * @param clazz
	 *            class to instantiate
	 * @return the new instance
	 * @throws BeanInstantiationException
	 *             if the bean cannot be instantiated
	 */
	public static <T> T instantiate(Class<T> clazz) throws BeanInstantiationException {
		Assert.notNull(clazz, "Class must not be null");
		if (clazz.isInterface()) {
			throw new BeanInstantiationException(clazz, "Specified class is an interface");
		}
		try {
			return clazz.newInstance();
		} catch (InstantiationException ex) {
			throw new BeanInstantiationException(clazz, "Is it an abstract class?", ex);
		} catch (IllegalAccessException ex) {
			throw new BeanInstantiationException(clazz, "Is the constructor accessible?", ex);
		}
	}

	/**
	 * Convenience method to instantiate a class using its no-arg constructor.
	 * As this method doesn't try to load classes by name, it should avoid
	 * class-loading issues.
	 * <p>
	 * Note that this method tries to set the constructor accessible if given a
	 * non-accessible (that is, non-public) constructor.
	 * 
	 * @param clazz
	 *            class to instantiate
	 * @return the new instance
	 * @throws BeanInstantiationException
	 *             if the bean cannot be instantiated
	 */
	public static <T> T instantiateClass(Class<T> clazz) throws BeanInstantiationException {
		Assert.notNull(clazz, "Class must not be null");
		if (clazz.isInterface()) {
			throw new BeanInstantiationException(clazz, "Specified class is an interface");
		}
		try {
			return instantiateClass(clazz.getDeclaredConstructor());
		} catch (NoSuchMethodException ex) {
			throw new BeanInstantiationException(clazz, "No default constructor found", ex);
		}
	}

	/**
	 * Convenience method to instantiate a class using the given constructor. As
	 * this method doesn't try to load classes by name, it should avoid
	 * class-loading issues.
	 * <p>
	 * Note that this method tries to set the constructor accessible if given a
	 * non-accessible (that is, non-public) constructor.
	 * 
	 * @param ctor
	 *            the constructor to instantiate
	 * @param args
	 *            the constructor arguments to apply
	 * @return the new instance
	 * @throws BeanInstantiationException
	 *             if the bean cannot be instantiated
	 */
	public static <T> T instantiateClass(Constructor<T> ctor, Object... args) throws BeanInstantiationException {
		Assert.notNull(ctor, "Constructor must not be null");
		try {
			ReflectionUtils.makeAccessible(ctor);
			return ctor.newInstance(args);
		} catch (InstantiationException ex) {
			throw new BeanInstantiationException(ctor.getDeclaringClass(), "Is it an abstract class?", ex);
		} catch (IllegalAccessException ex) {
			throw new BeanInstantiationException(ctor.getDeclaringClass(), "Is the constructor accessible?", ex);
		} catch (IllegalArgumentException ex) {
			throw new BeanInstantiationException(ctor.getDeclaringClass(), "Illegal arguments for constructor", ex);
		} catch (InvocationTargetException ex) {
			throw new BeanInstantiationException(ctor.getDeclaringClass(), "Constructor threw exception", ex.getTargetException());
		}
	}

	/**
	 * Find a method with the given method name and the given parameter types,
	 * declared on the given class or one of its superclasses. Prefers public
	 * methods, but will return a protected, package access, or private method
	 * too.
	 * <p>
	 * Checks <code>Class.getMethod</code> first, falling back to
	 * <code>findDeclaredMethod</code>. This allows to find public methods
	 * without issues even in environments with restricted Java security
	 * settings.
	 * 
	 * @param clazz
	 *            the class to check
	 * @param methodName
	 *            the name of the method to find
	 * @param paramTypes
	 *            the parameter types of the method to find
	 * @return the Method object, or <code>null</code> if not found
	 * @see java.lang.Class#getMethod
	 * @see #findDeclaredMethod
	 */
	public static Method findMethod(Class<?> clazz, String methodName, Class<?>... paramTypes) {
		try {
			return clazz.getMethod(methodName, paramTypes);
		} catch (NoSuchMethodException ex) {
			return findDeclaredMethod(clazz, methodName, paramTypes);
		}
	}

	/**
	 * Find a method with the given method name and the given parameter types,
	 * declared on the given class or one of its superclasses. Will return a
	 * public, protected, package access, or private method.
	 * <p>
	 * Checks <code>Class.getDeclaredMethod</code>, cascading upwards to all
	 * superclasses.
	 * 
	 * @param clazz
	 *            the class to check
	 * @param methodName
	 *            the name of the method to find
	 * @param paramTypes
	 *            the parameter types of the method to find
	 * @return the Method object, or <code>null</code> if not found
	 * @see java.lang.Class#getDeclaredMethod
	 */
	public static Method findDeclaredMethod(Class<?> clazz, String methodName, Class<?>[] paramTypes) {
		try {
			return clazz.getDeclaredMethod(methodName, paramTypes);
		} catch (NoSuchMethodException ex) {
			if (clazz.getSuperclass() != null) {
				return findDeclaredMethod(clazz.getSuperclass(), methodName, paramTypes);
			}
			return null;
		}
	}

	/**
	 * Find a method with the given method name and minimal parameters (best
	 * case: none), declared on the given class or one of its superclasses.
	 * Prefers public methods, but will return a protected, package access, or
	 * private method too.
	 * <p>
	 * Checks <code>Class.getMethods</code> first, falling back to
	 * <code>findDeclaredMethodWithMinimalParameters</code>. This allows for
	 * finding public methods without issues even in environments with
	 * restricted Java security settings.
	 * 
	 * @param clazz
	 *            the class to check
	 * @param methodName
	 *            the name of the method to find
	 * @return the Method object, or <code>null</code> if not found
	 * @throws IllegalArgumentException
	 *             if methods of the given name were found but could not be
	 *             resolved to a unique method with minimal parameters
	 * @see java.lang.Class#getMethods
	 * @see #findDeclaredMethodWithMinimalParameters
	 */
	public static Method findMethodWithMinimalParameters(Class<?> clazz, String methodName) throws IllegalArgumentException {

		Method targetMethod = findMethodWithMinimalParameters(clazz.getMethods(), methodName);
		if (targetMethod == null) {
			targetMethod = findDeclaredMethodWithMinimalParameters(clazz, methodName);
		}
		return targetMethod;
	}

	/**
	 * Find a method with the given method name and minimal parameters (best
	 * case: none), declared on the given class or one of its superclasses. Will
	 * return a public, protected, package access, or private method.
	 * <p>
	 * Checks <code>Class.getDeclaredMethods</code>, cascading upwards to all
	 * superclasses.
	 * 
	 * @param clazz
	 *            the class to check
	 * @param methodName
	 *            the name of the method to find
	 * @return the Method object, or <code>null</code> if not found
	 * @throws IllegalArgumentException
	 *             if methods of the given name were found but could not be
	 *             resolved to a unique method with minimal parameters
	 * @see java.lang.Class#getDeclaredMethods
	 */
	public static Method findDeclaredMethodWithMinimalParameters(Class<?> clazz, String methodName) throws IllegalArgumentException {

		Method targetMethod = findMethodWithMinimalParameters(clazz.getDeclaredMethods(), methodName);
		if (targetMethod == null && clazz.getSuperclass() != null) {
			targetMethod = findDeclaredMethodWithMinimalParameters(clazz.getSuperclass(), methodName);
		}
		return targetMethod;
	}

	/**
	 * Find a method with the given method name and minimal parameters (best
	 * case: none) in the given list of methods.
	 * 
	 * @param methods
	 *            the methods to check
	 * @param methodName
	 *            the name of the method to find
	 * @return the Method object, or <code>null</code> if not found
	 * @throws IllegalArgumentException
	 *             if methods of the given name were found but could not be
	 *             resolved to a unique method with minimal parameters
	 */
	public static Method findMethodWithMinimalParameters(Method[] methods, String methodName) throws IllegalArgumentException {

		Method targetMethod = null;
		int numMethodsFoundWithCurrentMinimumArgs = 0;
		for (Method method : methods) {
			if (method.getName().equals(methodName)) {
				int numParams = method.getParameterTypes().length;
				if (targetMethod == null || numParams < targetMethod.getParameterTypes().length) {
					targetMethod = method;
					numMethodsFoundWithCurrentMinimumArgs = 1;
				} else {
					if (targetMethod.getParameterTypes().length == numParams) {
						// Additional candidate with same length.
						numMethodsFoundWithCurrentMinimumArgs++;
					}
				}
			}
		}
		if (numMethodsFoundWithCurrentMinimumArgs > 1) {
			throw new IllegalArgumentException("Cannot resolve method '" + methodName
					+ "' to a unique method. Attempted to resolve to overloaded method with " + "the least number of parameters, but there were "
					+ numMethodsFoundWithCurrentMinimumArgs + " candidates.");
		}
		return targetMethod;
	}

	/**
	 * Parse a method signature in the form
	 * <code>methodName[([arg_list])]</code>, where <code>arg_list</code> is an
	 * optional, comma-separated list of fully-qualified type names, and
	 * attempts to resolve that signature against the supplied
	 * <code>Class</code>.
	 * <p>
	 * When not supplying an argument list (<code>methodName</code>) the method
	 * whose name matches and has the least number of parameters will be
	 * returned. When supplying an argument type list, only the method whose
	 * name and argument types match will be returned.
	 * <p>
	 * Note then that <code>methodName</code> and <code>methodName()</code> are
	 * <strong>not</strong> resolved in the same way. The signature
	 * <code>methodName</code> means the method called <code>methodName</code>
	 * with the least number of arguments, whereas <code>methodName()</code>
	 * means the method called <code>methodName</code> with exactly 0 arguments.
	 * <p>
	 * If no method can be found, then <code>null</code> is returned.
	 * 
	 * @param signature
	 *            the method signature as String representation
	 * @param clazz
	 *            the class to resolve the method signature against
	 * @return the resolved Method
	 * @see #findMethod
	 * @see #findMethodWithMinimalParameters
	 */
	public static Method resolveSignature(String signature, Class<?> clazz) {
		Assert.hasText(signature, "'signature' must not be empty");
		Assert.notNull(clazz, "Class must not be null");

		int firstParen = signature.indexOf("(");
		int lastParen = signature.indexOf(")");

		if (firstParen > -1 && lastParen == -1) {
			throw new IllegalArgumentException("Invalid method signature '" + signature + "': expected closing ')' for args list");
		} else if (lastParen > -1 && firstParen == -1) {
			throw new IllegalArgumentException("Invalid method signature '" + signature + "': expected opening '(' for args list");
		} else if (firstParen == -1 && lastParen == -1) {
			return findMethodWithMinimalParameters(clazz, signature);
		} else {
			String methodName = signature.substring(0, firstParen);
			String[] parameterTypeNames = StringUtils.commaDelimitedListToStringArray(signature.substring(firstParen + 1, lastParen));
			Class<?>[] parameterTypes = new Class[parameterTypeNames.length];
			for (int i = 0; i < parameterTypeNames.length; i++) {
				String parameterTypeName = parameterTypeNames[i].trim();
				try {
					parameterTypes[i] = ClassUtils.forName(parameterTypeName, clazz.getClassLoader());
				} catch (Throwable ex) {
					throw new IllegalArgumentException("Invalid method signature: unable to resolve type [" + parameterTypeName + "] for argument "
							+ i + ". Root cause: " + ex);
				}
			}
			return findMethod(clazz, methodName, parameterTypes);
		}
	}

	/**
	 * Retrieve the JavaBeans <code>PropertyDescriptor</code>s of a given class.
	 * 
	 * @param clazz
	 *            the Class to retrieve the PropertyDescriptors for
	 * @return an array of <code>PropertyDescriptors</code> for the given class
	 * @throws BeansException
	 *             if PropertyDescriptor look fails
	 */
	public static PropertyDescriptor[] getPropertyDescriptors(Class<?> clazz) throws BeansException {
		CachedIntrospectionResults cr = CachedIntrospectionResults.forClass(clazz);
		return cr.getPropertyDescriptors();
	}

	/**
	 * Retrieve the JavaBeans <code>PropertyDescriptors</code> for the given
	 * property.
	 * 
	 * @param clazz
	 *            the Class to retrieve the PropertyDescriptor for
	 * @param propertyName
	 *            the name of the property
	 * @return the corresponding PropertyDescriptor, or <code>null</code> if
	 *         none
	 * @throws BeansException
	 *             if PropertyDescriptor lookup fails
	 */
	public static PropertyDescriptor getPropertyDescriptor(Class<?> clazz, String propertyName) throws BeansException {

		CachedIntrospectionResults cr = CachedIntrospectionResults.forClass(clazz);
		return cr.getPropertyDescriptor(propertyName);
	}

	/**
	 * Find a JavaBeans <code>PropertyDescriptor</code> for the given method,
	 * with the method either being the read method or the write method for that
	 * bean property.
	 * 
	 * @param method
	 *            the method to find a corresponding PropertyDescriptor for
	 * @return the corresponding PropertyDescriptor, or <code>null</code> if
	 *         none
	 * @throws BeansException
	 *             if PropertyDescriptor lookup fails
	 */
	public static PropertyDescriptor findPropertyForMethod(Method method) throws BeansException {
		Assert.notNull(method, "Method must not be null");
		PropertyDescriptor[] pds = getPropertyDescriptors(method.getDeclaringClass());
		for (PropertyDescriptor pd : pds) {
			if (method.equals(pd.getReadMethod()) || method.equals(pd.getWriteMethod())) {
				return pd;
			}
		}
		return null;
	}

	/**
	 * 尝试通过在原有类名上增加一个'Editor'后缀的方式来寻找一个JavaBean的属性编辑器
	 * (例如类 "mypackage.MyDomainClass" 的属性编辑器类就是 "mypackage.MyDomainClassEditor").
	 * <p>
	 * 
	 * Compatible to the standard JavaBeans convention as implemented by {@link java.beans.PropertyEditorManager} but isolated from the latter's registered default editors for primitive types.
	 * 
	 * @param targetType 需要查找编辑器的类型
	 * @return 对应的属性编辑器, 找不到时返回<code>null</code>
	 */
	public static PropertyEditor findEditorByConvention(Class<?> targetType) {
		if (targetType == null || targetType.isArray() || unknownEditorTypes.containsKey(targetType)) {
			return null;
		}
		ClassLoader cl = targetType.getClassLoader();
		if (cl == null) {
			try {
				cl = ClassLoader.getSystemClassLoader();
				if (cl == null) {
					return null;
				}
			} catch (Throwable ex) {
				if (log.isDebugEnabled()) {
					log.debug("无法获取系统ClassLoader: " + ex);
				}
				return null;
			}
		}
		String editorName = targetType.getName() + "Editor";
		try {
			Class<?> editorClass = cl.loadClass(editorName);
			if (!PropertyEditor.class.isAssignableFrom(editorClass)) {
				log.warn("编辑器类[" + editorName + "]没有实现[java.beans.PropertyEditor]接口");
				unknownEditorTypes.put(targetType, Boolean.TRUE);
				return null;
			}
			return (PropertyEditor) instantiateClass(editorClass);
		} catch (ClassNotFoundException ex) {
			if (log.isDebugEnabled()) {
				log.debug("找不到类型为" + targetType.getName() + "的属性编辑器类 [" + editorName + "]");
			}
			unknownEditorTypes.put(targetType, Boolean.TRUE);
			return null;
		}
	}

	/**
	 * Determine the bean property type for the given property from the given
	 * classes/interfaces, if possible.
	 * 
	 * @param propertyName
	 *            the name of the bean property
	 * @param beanClasses
	 *            the classes to check against
	 * @return the property type, or <code>Object.class</code> as fallback
	 */
	public static Class<?> findPropertyType(String propertyName, Class<?>[] beanClasses) {
		if (beanClasses != null) {
			for (Class<?> beanClass : beanClasses) {
				PropertyDescriptor pd = getPropertyDescriptor(beanClass, propertyName);
				if (pd != null) {
					return pd.getPropertyType();
				}
			}
		}
		return Object.class;
	}

	/**
	 * Obtain a new MethodParameter object for the write method of the specified
	 * property.
	 * 
	 * @param pd
	 *            the PropertyDescriptor for the property
	 * @return a corresponding MethodParameter object
	 */
	public static MethodParameter getWriteMethodParameter(PropertyDescriptor pd) {
		return new MethodParameter(pd.getWriteMethod(), 0);
	}

	/**
	 * Check if the given type represents a "simple" property: a primitive, a
	 * String or other CharSequence, a Number, a Date, a URI, a URL, a Locale, a
	 * Class, or a corresponding array.
	 * <p>
	 * Used to determine properties to check for a "simple" dependency-check.
	 * 
	 * @param clazz
	 *            the type to check
	 * @return whether the given type represents a "simple" property
	 * @see org.theonefx.wcframework.ioc.support.RootBeanDefinition#DEPENDENCY_CHECK_SIMPLE
	 */
	public static boolean isSimpleProperty(Class<?> clazz) {
		Assert.notNull(clazz, "Class must not be null");
		return isSimpleValueType(clazz) || (clazz.isArray() && isSimpleValueType(clazz.getComponentType()));
	}

	/**
	 * Check if the given type represents a "simple" value type: a primitive, a
	 * String or other CharSequence, a Number, a Date, a URI, a URL, a Locale or
	 * a Class.
	 * 
	 * @param clazz
	 *            the type to check
	 * @return whether the given type represents a "simple" value type
	 */
	public static boolean isSimpleValueType(Class<?> clazz) {
		return ClassUtils.isPrimitiveOrWrapper(clazz) || clazz.isEnum() || CharSequence.class.isAssignableFrom(clazz)
				|| Number.class.isAssignableFrom(clazz) || Date.class.isAssignableFrom(clazz) || clazz.equals(URI.class) || clazz.equals(URL.class)
				|| clazz.equals(Locale.class) || clazz.equals(Class.class);
	}

	/**
	 * Copy the property values of the given source bean into the target bean.
	 * <p>
	 * Note: The source and target classes do not have to match or even be
	 * derived from each other, as long as the properties match. Any bean
	 * properties that the source bean exposes but the target bean does not will
	 * silently be ignored.
	 * <p>
	 * This is just a convenience method. For more complex transfer needs,
	 * consider using a full BeanWrapper.
	 * 
	 * @param source
	 *            the source bean
	 * @param target
	 *            the target bean
	 * @throws BeansException
	 *             if the copying failed
	 * @see BeanWrapper
	 */
	public static void copyProperties(Object source, Object target) throws BeansException {
		copyProperties(source, target, null, null);
	}

	/**
	 * Copy the property values of the given source bean into the given target
	 * bean, only setting properties defined in the given "editable" class (or
	 * interface).
	 * <p>
	 * Note: The source and target classes do not have to match or even be
	 * derived from each other, as long as the properties match. Any bean
	 * properties that the source bean exposes but the target bean does not will
	 * silently be ignored.
	 * <p>
	 * This is just a convenience method. For more complex transfer needs,
	 * consider using a full BeanWrapper.
	 * 
	 * @param source
	 *            the source bean
	 * @param target
	 *            the target bean
	 * @param editable
	 *            the class (or interface) to restrict property setting to
	 * @throws BeansException
	 *             if the copying failed
	 * @see BeanWrapper
	 */
	public static void copyProperties(Object source, Object target, Class<?> editable) throws BeansException {

		copyProperties(source, target, editable, null);
	}

	/**
	 * Copy the property values of the given source bean into the given target
	 * bean, ignoring the given "ignoreProperties".
	 * <p>
	 * Note: The source and target classes do not have to match or even be
	 * derived from each other, as long as the properties match. Any bean
	 * properties that the source bean exposes but the target bean does not will
	 * silently be ignored.
	 * <p>
	 * This is just a convenience method. For more complex transfer needs,
	 * consider using a full BeanWrapper.
	 * 
	 * @param source
	 *            the source bean
	 * @param target
	 *            the target bean
	 * @param ignoreProperties
	 *            array of property names to ignore
	 * @throws BeansException
	 *             if the copying failed
	 * @see BeanWrapper
	 */
	public static void copyProperties(Object source, Object target, String[] ignoreProperties) throws BeansException {

		copyProperties(source, target, null, ignoreProperties);
	}

	/**
	 * Copy the property values of the given source bean into the given target
	 * bean.
	 * <p>
	 * Note: The source and target classes do not have to match or even be
	 * derived from each other, as long as the properties match. Any bean
	 * properties that the source bean exposes but the target bean does not will
	 * silently be ignored.
	 * 
	 * @param source
	 *            the source bean
	 * @param target
	 *            the target bean
	 * @param editable
	 *            the class (or interface) to restrict property setting to
	 * @param ignoreProperties
	 *            array of property names to ignore
	 * @throws BeansException
	 *             if the copying failed
	 * @see BeanWrapper
	 */
	private static void copyProperties(Object source, Object target, Class<?> editable, String[] ignoreProperties) throws BeansException {

		Assert.notNull(source, "Source must not be null");
		Assert.notNull(target, "Target must not be null");

		Class<?> actualEditable = target.getClass();
		if (editable != null) {
			if (!editable.isInstance(target)) {
				throw new IllegalArgumentException("Target class [" + target.getClass().getName() + "] not assignable to Editable class ["
						+ editable.getName() + "]");
			}
			actualEditable = editable;
		}
		PropertyDescriptor[] targetPds = getPropertyDescriptors(actualEditable);
		List<String> ignoreList = (ignoreProperties != null) ? Arrays.asList(ignoreProperties) : null;

		for (PropertyDescriptor targetPd : targetPds) {
			if (targetPd.getWriteMethod() != null && (ignoreProperties == null || (!ignoreList.contains(targetPd.getName())))) {
				PropertyDescriptor sourcePd = getPropertyDescriptor(source.getClass(), targetPd.getName());
				if (sourcePd != null && sourcePd.getReadMethod() != null) {
					try {
						Method readMethod = sourcePd.getReadMethod();
						if (!Modifier.isPublic(readMethod.getDeclaringClass().getModifiers())) {
							readMethod.setAccessible(true);
						}
						Object value = readMethod.invoke(source);
						Method writeMethod = targetPd.getWriteMethod();
						if (!Modifier.isPublic(writeMethod.getDeclaringClass().getModifiers())) {
							writeMethod.setAccessible(true);
						}
						writeMethod.invoke(target, value);
					} catch (Throwable ex) {
						throw new FatalBeanException("Could not copy properties from source to target", ex);
					}
				}
			}
		}
	}

}