propertyaccessorutils.java

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/*
 * Copyright 2002-2006 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans;

/**
 * Utility methods for classes that perform bean property access
 * according to the PropertyAccessor interface.
 *
 * @author Juergen Hoeller
 * @since 1.2.6
 * @see PropertyAccessor
 */
public abstract class PropertyAccessorUtils {

	/**
	 * Return the actual property name for the given property path.
	 * @param propertyPath the property path to determine the property name
	 * for (can include property keys, for example for specifying a map entry)
	 * @return the actual property name, without any key elements
	 */
	public static String getPropertyName(String propertyPath) {
		int separatorIndex = propertyPath.indexOf(PropertyAccessor.PROPERTY_KEY_PREFIX_CHAR);
		return (separatorIndex != -1 ? propertyPath.substring(0, separatorIndex) : propertyPath);
	}

	/**
	 * Determine the first nested property separator in the
	 * given property path, ignoring dots in keys (like "map[my.key]").
	 * @param propertyPath the property path to check
	 * @return the index of the nested property separator, or -1 if none
	 */
	public static int getFirstNestedPropertySeparatorIndex(String propertyPath) {
		return getNestedPropertySeparatorIndex(propertyPath, false);
	}

	/**
	 * Determine the first nested property separator in the
	 * given property path, ignoring dots in keys (like "map[my.key]").
	 * @param propertyPath the property path to check
	 * @return the index of the nested property separator, or -1 if none
	 */
	public static int getLastNestedPropertySeparatorIndex(String propertyPath) {
		return getNestedPropertySeparatorIndex(propertyPath, true);
	}

	/**
	 * Determine the first (or last) nested property separator in the
	 * given property path, ignoring dots in keys (like "map[my.key]").
	 * @param propertyPath the property path to check
	 * @param last whether to return the last separator rather than the first
	 * @return the index of the nested property separator, or -1 if none
	 */
	private static int getNestedPropertySeparatorIndex(String propertyPath, boolean last) {
		boolean inKey = false;
		final int length = propertyPath.length();
		int i = (last ? length - 1 : 0);
		while (last ? i >= 0 : i < length) {
			switch (propertyPath.charAt(i)) {
				case PropertyAccessor.PROPERTY_KEY_PREFIX_CHAR:
				case PropertyAccessor.PROPERTY_KEY_SUFFIX_CHAR:
					inKey = !inKey;
					break;
				case PropertyAccessor.NESTED_PROPERTY_SEPARATOR_CHAR:
					if (!inKey) {
						return i;
					}
			}
			if (last)
				i--;
			else
				i++;
		}
		return -1;
	}

	/**
	 * Determine the canonical name for the given property path.
	 * Removes surrounding quotes from map keys:<br>
	 * <code>map['key']</code> -> <code>map[key]</code><br>
	 * <code>map["key"]</code> -> <code>map[key]</code>
	 * @param propertyName the bean property path
	 * @return the canonical representation of the property path
	 */
	public static String canonicalPropertyName(String propertyName) {
		if (propertyName == null) {
			return "";
		}

		// The following code does not use JDK 1.4's StringBuffer.indexOf(String)
		// method to retain JDK 1.3 compatibility. The slight loss in performance
		// is not really relevant, as this code will typically just run on startup.

		StringBuffer buf = new StringBuffer(propertyName);
		int searchIndex = 0;
		while (searchIndex != -1) {
			int keyStart = buf.toString().indexOf(PropertyAccessor.PROPERTY_KEY_PREFIX, searchIndex);
			searchIndex = -1;
			if (keyStart != -1) {
				int keyEnd = buf.toString().indexOf(
						PropertyAccessor.PROPERTY_KEY_SUFFIX, keyStart + PropertyAccessor.PROPERTY_KEY_PREFIX.length());
				if (keyEnd != -1) {
					String key = buf.substring(keyStart + PropertyAccessor.PROPERTY_KEY_PREFIX.length(), keyEnd);
					if ((key.startsWith("'") && key.endsWith("'")) || (key.startsWith("\"") && key.endsWith("\""))) {
						buf.delete(keyStart + 1, keyStart + 2);
						buf.delete(keyEnd - 2, keyEnd - 1);
						keyEnd = keyEnd - 2;
					}
					searchIndex = keyEnd + PropertyAccessor.PROPERTY_KEY_SUFFIX.length();
				}
			}
		}
		return buf.toString();
	}

	/**
	 * Determine the canonical names for the given property paths.
	 * @param propertyNames the bean property paths (as array)
	 * @return the canonical representation of the property paths
	 * (as array of the same size)
	 * @see #canonicalPropertyName(String)
	 */
	public static String[] canonicalPropertyNames(String[] propertyNames) {
		if (propertyNames == null) {
			return null;
		}
		String[] result = new String[propertyNames.length];
		for (int i = 0; i < propertyNames.length; i++) {
			result[i] = canonicalPropertyName(propertyNames[i]);
		}
		return result;
	}

}