classutils.java

Spring源代码,开源的srcorgspringframeworkwebmultipartMultipartFile.java MVC上传文件

	 * @param method the method
	 * @return the qualified name of the method
	 */
	public static String getQualifiedMethodName(Method method) {
		Assert.notNull(method, "Method must not be null");
		return method.getDeclaringClass().getName() + "." + method.getName();
	}


	/**
	 * Determine whether the given class has a method with the given signature.
	 * <p>Essentially translates <code>NoSuchMethodException</code> to "false".
	 * @param clazz	the clazz to analyze
	 * @param methodName the name of the method
	 * @param paramTypes the parameter types of the method
	 * @see java.lang.Class#getMethod
	 */
	public static boolean hasMethod(Class clazz, String methodName, Class[] paramTypes) {
		return (getMethodIfAvailable(clazz, methodName, paramTypes) != null);
	}

	/**
	 * Determine whether the given class has a method with the given signature,
	 * and return it if available (else return <code>null</code>).
	 * <p>Essentially translates <code>NoSuchMethodException</code> to <code>null</code>.
	 * @param clazz	the clazz to analyze
	 * @param methodName the name of the method
	 * @param paramTypes the parameter types of the method
	 * @return the method, or <code>null</code> if not found
	 * @see java.lang.Class#getMethod
	 */
	public static Method getMethodIfAvailable(Class clazz, String methodName, Class[] paramTypes) {
		Assert.notNull(clazz, "Class must not be null");
		Assert.notNull(methodName, "Method name must not be null");
		try {
			return clazz.getMethod(methodName, paramTypes);
		}
		catch (NoSuchMethodException ex) {
			return null;
		}
	}

	/**
	 * Return the number of methods with a given name (with any argument types),
	 * for the given class and/or its superclasses. Includes non-public methods.
	 * @param clazz	the clazz to check
	 * @param methodName the name of the method
	 * @return the number of methods with the given name
	 */
	public static int getMethodCountForName(Class clazz, String methodName) {
		Assert.notNull(clazz, "Class must not be null");
		Assert.notNull(methodName, "Method name must not be null");
		int count = 0;
		for (int i = 0; i < clazz.getDeclaredMethods().length; i++) {
			Method method = clazz.getDeclaredMethods()[i];
			if (methodName.equals(method.getName())) {
				count++;
			}
		}
		Class[] ifcs = clazz.getInterfaces();
		for (int i = 0; i < ifcs.length; i++) {
			count += getMethodCountForName(ifcs[i], methodName);
		}
		if (clazz.getSuperclass() != null) {
			count += getMethodCountForName(clazz.getSuperclass(), methodName);
		}
		return count;
	}

	/**
	 * Does the given class and/or its superclasses at least have one or more
	 * methods (with any argument types)? Includes non-public methods.
	 * @param clazz	the clazz to check
	 * @param methodName the name of the method
	 * @return whether there is at least one method with the given name
	 */
	public static boolean hasAtLeastOneMethodWithName(Class clazz, String methodName) {
		Assert.notNull(clazz, "Class must not be null");
		Assert.notNull(methodName, "Method name must not be null");
		for (int i = 0; i < clazz.getDeclaredMethods().length; i++) {
			Method method = clazz.getDeclaredMethods()[i];
			if (method.getName().equals(methodName)) {
				return true;
			}
		}
		Class[] ifcs = clazz.getInterfaces();
		for (int i = 0; i < ifcs.length; i++) {
			if (hasAtLeastOneMethodWithName(ifcs[i], methodName)) {
				return true;
			}
		}
		if (clazz.getSuperclass() != null) {
			return hasAtLeastOneMethodWithName(clazz.getSuperclass(), methodName);
		}
		return false;
	}

	/**
	 * Return a static method of a class.
	 * @param methodName the static method name
	 * @param clazz	the class which defines the method
	 * @param args the parameter types to the method
	 * @return the static method, or <code>null</code> if no static method was found
	 * @throws IllegalArgumentException if the method name is blank or the clazz is null
	 */
	public static Method getStaticMethod(Class clazz, String methodName, Class[] args) {
		Assert.notNull(clazz, "Class must not be null");
		Assert.notNull(methodName, "Method name must not be null");
		try {
			Method method = clazz.getDeclaredMethod(methodName, args);
			if ((method.getModifiers() & Modifier.STATIC) != 0) {
				return method;
			}
		}
		catch (NoSuchMethodException ex) {
		}
		return null;
	}


	/**
	 * Return a path suitable for use with <code>ClassLoader.getResource</code>
	 * (also suitable for use with <code>Class.getResource</code> by prepending a
	 * slash ('/') to the return value. Built by taking the package of the specified
	 * class file, converting all dots ('.') to slashes ('/'), adding a trailing slash
	 * if necesssary, and concatenating the specified resource name to this.
	 * <br/>As such, this function may be used to build a path suitable for
	 * loading a resource file that is in the same package as a class file,
	 * although {@link org.springframework.core.io.ClassPathResource} is usually
	 * even more convenient.
	 * @param clazz	the Class whose package will be used as the base
	 * @param resourceName the resource name to append. A leading slash is optional.
	 * @return the built-up resource path
	 * @see java.lang.ClassLoader#getResource
	 * @see java.lang.Class#getResource
	 */
	public static String addResourcePathToPackagePath(Class clazz, String resourceName) {
		Assert.notNull(resourceName, "Resource name must not be null");
		if (!resourceName.startsWith("/")) {
			return classPackageAsResourcePath(clazz) + "/" + resourceName;
		}
		return classPackageAsResourcePath(clazz) + resourceName;
	}

	/**
	 * Given an input class object, return a string which consists of the
	 * class's package name as a pathname, i.e., all dots ('.') are replaced by
	 * slashes ('/'). Neither a leading nor trailing slash is added. The result
	 * could be concatenated with a slash and the name of a resource, and fed
	 * directly to ClassLoader.getResource(). For it to be fed to Class.getResource,
	 * a leading slash would also have to be prepended to the return value.
	 * @param clazz the input class. A null value or the default (empty) package
	 * will result in an empty string ("") being returned.
	 * @return a path which represents the package name
	 * @see ClassLoader#getResource
	 * @see Class#getResource
	 */
	public static String classPackageAsResourcePath(Class clazz) {
		if (clazz == null || clazz.getPackage() == null) {
			return "";
		}
		return clazz.getPackage().getName().replace('.', '/');
	}

	/**
	 * Return all interfaces that the given object implements as array,
	 * including ones implemented by superclasses.
	 * @param object the object to analyse for interfaces
	 * @return all interfaces that the given object implements as array
	 */
	public static Class[] getAllInterfaces(Object object) {
		Set interfaces = getAllInterfacesAsSet(object);
		return (Class[]) interfaces.toArray(new Class[interfaces.size()]);
	}

	/**
	 * Return all interfaces that the given class implements as array,
	 * including ones implemented by superclasses.
	 * <p>If the class itself is an interface, it gets returned as sole interface.
	 * @param clazz the class to analyse for interfaces
	 * @return all interfaces that the given object implements as array
	 */
	public static Class[] getAllInterfacesForClass(Class clazz) {
		Set interfaces = getAllInterfacesForClassAsSet(clazz);
		return (Class[]) interfaces.toArray(new Class[interfaces.size()]);
	}

	/**
	 * Return all interfaces that the given object implements as List,
	 * including ones implemented by superclasses.
	 * @param object the object to analyse for interfaces
	 * @return all interfaces that the given object implements as List
	 */
	public static Set getAllInterfacesAsSet(Object object) {
		Assert.notNull(object, "Object must not be null");
		return getAllInterfacesForClassAsSet(object.getClass());
	}

	/**
	 * Return all interfaces that the given class implements as Set,
	 * including ones implemented by superclasses.
	 * <p>If the class itself is an interface, it gets returned as sole interface.
	 * @param clazz the class to analyse for interfaces
	 * @return all interfaces that the given object implements as Set
	 */
	public static Set getAllInterfacesForClassAsSet(Class clazz) {
		Assert.notNull(clazz, "Class must not be null");
		if (clazz.isInterface()) {
			return Collections.singleton(clazz);
		}
		Set interfaces = new HashSet();
		while (clazz != null) {
			for (int i = 0; i < clazz.getInterfaces().length; i++) {
				Class ifc = clazz.getInterfaces()[i];
				interfaces.add(ifc);
			}
			clazz = clazz.getSuperclass();
		}
		return interfaces;
	}

}