Java tutorial
/* * Copyright 2002-2017 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 * * https://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; import org.springframework.lang.Nullable; /** * Utility methods for classes that perform bean property access * according to the {@link PropertyAccessor} interface. * * @author Juergen Hoeller * @since 1.2.6 */ 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.endsWith(PropertyAccessor.PROPERTY_KEY_SUFFIX) ? propertyPath.indexOf(PropertyAccessor.PROPERTY_KEY_PREFIX_CHAR) : -1); return (separatorIndex != -1 ? propertyPath.substring(0, separatorIndex) : propertyPath); } /** * Check whether the given property path indicates an indexed or nested property. * @param propertyPath the property path to check * @return whether the path indicates an indexed or nested property */ public static boolean isNestedOrIndexedProperty(@Nullable String propertyPath) { if (propertyPath == null) { return false; } for (int i = 0; i < propertyPath.length(); i++) { char ch = propertyPath.charAt(i); if (ch == PropertyAccessor.NESTED_PROPERTY_SEPARATOR_CHAR || ch == PropertyAccessor.PROPERTY_KEY_PREFIX_CHAR) { return true; } } return 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 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; 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 whether the given registered path matches the given property path, * either indicating the property itself or an indexed element of the property. * @param propertyPath the property path (typically without index) * @param registeredPath the registered path (potentially with index) * @return whether the paths match */ public static boolean matchesProperty(String registeredPath, String propertyPath) { if (!registeredPath.startsWith(propertyPath)) { return false; } if (registeredPath.length() == propertyPath.length()) { return true; } if (registeredPath.charAt(propertyPath.length()) != PropertyAccessor.PROPERTY_KEY_PREFIX_CHAR) { return false; } return (registeredPath.indexOf(PropertyAccessor.PROPERTY_KEY_SUFFIX_CHAR, propertyPath.length() + 1) == registeredPath.length() - 1); } /** * Determine the canonical name for the given property path. * Removes surrounding quotes from map keys:<br> * {@code map['key']} -> {@code map[key]}<br> * {@code map["key"]} -> {@code map[key]} * @param propertyName the bean property path * @return the canonical representation of the property path */ public static String canonicalPropertyName(@Nullable String propertyName) { if (propertyName == null) { return ""; } StringBuilder sb = new StringBuilder(propertyName); int searchIndex = 0; while (searchIndex != -1) { int keyStart = sb.indexOf(PropertyAccessor.PROPERTY_KEY_PREFIX, searchIndex); searchIndex = -1; if (keyStart != -1) { int keyEnd = sb.indexOf(PropertyAccessor.PROPERTY_KEY_SUFFIX, keyStart + PropertyAccessor.PROPERTY_KEY_PREFIX.length()); if (keyEnd != -1) { String key = sb.substring(keyStart + PropertyAccessor.PROPERTY_KEY_PREFIX.length(), keyEnd); if ((key.startsWith("'") && key.endsWith("'")) || (key.startsWith("\"") && key.endsWith("\""))) { sb.delete(keyStart + 1, keyStart + 2); sb.delete(keyEnd - 2, keyEnd - 1); keyEnd = keyEnd - 2; } searchIndex = keyEnd + PropertyAccessor.PROPERTY_KEY_SUFFIX.length(); } } } return sb.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) */ @Nullable public static String[] canonicalPropertyNames(@Nullable 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; } }