| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.tools.ant.property; |
| |
| import java.text.ParsePosition; |
| import java.util.Collection; |
| import java.util.Objects; |
| |
| import org.apache.tools.ant.Project; |
| |
| /** |
| * Parse properties using a collection of expanders. |
| * |
| * @since Ant 1.8.0 |
| */ |
| public class ParseProperties implements ParseNextProperty { |
| |
| private final Project project; |
| private final GetProperty getProperty; |
| private final Collection<PropertyExpander> expanders; |
| |
| /** |
| * Constructor with a getProperty. |
| * @param project the current Ant project. |
| * @param expanders a sequence of expanders |
| * @param getProperty property resolver. |
| */ |
| public ParseProperties(Project project, Collection<PropertyExpander> expanders, GetProperty getProperty) { |
| this.project = project; |
| this.expanders = expanders; |
| this.getProperty = getProperty; |
| } |
| |
| /** |
| * Get the project. |
| * @return the current Ant project. |
| */ |
| @Override |
| public Project getProject() { |
| return project; |
| } |
| |
| /** |
| * Decode properties from a String representation. |
| * |
| * <ul> |
| * |
| * <li>This implementation starts parsing the <code>value</code> |
| * parameter (unsurprisingly) at the beginning and asks each |
| * {@link PropertyExpander PropertyExpander} whether there is a |
| * property reference at that point. PropertyExpanders return |
| * the name of a property they may find and may advance the parse |
| * position.</li> |
| * |
| * <li>If the PropertyExpander returns <code>null</code> the |
| * method continues with the next PropertyExpander, otherwise it |
| * tries to look up the property's value using the configured |
| * {@link GetProperty GetProperty} instance.</li> |
| * |
| * <li>Once all PropertyExpanders have been consulted, the parse |
| * position is advanced by one character and the process repeated |
| * until <code>value</code> is exhausted.</li> |
| * |
| * </ul> |
| * |
| * <p>If the entire contents of <code>value</code> resolves to a |
| * single property, the looked up property value is returned. |
| * Otherwise a String is returned that concatenates the |
| * non-property parts of <code>value</code> and the expanded |
| * values of the properties that have been found.</p> |
| * |
| * @param value The string to be scanned for property references. |
| * May be <code>null</code>, in which case this |
| * method returns immediately with no effect. |
| * |
| * @return the original string with the properties replaced, or |
| * <code>null</code> if the original string is <code>null</code>. |
| */ |
| public Object parseProperties(String value) { |
| if (value == null || value.isEmpty()) { |
| return value; |
| } |
| final int len = value.length(); |
| ParsePosition pos = new ParsePosition(0); |
| Object o = parseNextProperty(value, pos); |
| if (o != null && pos.getIndex() >= len) { |
| return o; |
| } |
| StringBuilder sb = new StringBuilder(len * 2); |
| if (o == null) { |
| sb.append(value.charAt(pos.getIndex())); |
| pos.setIndex(pos.getIndex() + 1); |
| } else { |
| sb.append(o); |
| } |
| while (pos.getIndex() < len) { |
| o = parseNextProperty(value, pos); |
| if (o == null) { |
| sb.append(value.charAt(pos.getIndex())); |
| pos.setIndex(pos.getIndex() + 1); |
| } else { |
| sb.append(o); |
| } |
| } |
| return sb.toString(); |
| } |
| |
| /** |
| * Learn whether a String contains replaceable properties. |
| * |
| * <p>Uses the configured {@link PropertyExpander |
| * PropertyExpanders} and scans through the string. Returns true |
| * as soon as any expander finds a property.</p> |
| * |
| * @param value the String to check. |
| * @return <code>true</code> if <code>value</code> contains property notation. |
| */ |
| public boolean containsProperties(String value) { |
| if (value == null) { |
| return false; |
| } |
| final int len = value.length(); |
| for (ParsePosition pos = new ParsePosition(0); pos.getIndex() < len;) { |
| if (parsePropertyName(value, pos) != null) { |
| return true; |
| } |
| pos.setIndex(pos.getIndex() + 1); |
| } |
| return false; |
| } |
| |
| /** |
| * Return any property that can be parsed from the specified position |
| * in the specified String. |
| * |
| * <p>Uses the configured {@link PropertyExpander |
| * PropertyExpanders} and {@link GetProperty GetProperty} |
| * instance .</p> |
| * |
| * @param value String to parse |
| * @param pos ParsePosition |
| * @return Object or null if no property is at the current |
| * location. If a property reference has been found but the |
| * property doesn't expand to a value, the property's name is |
| * returned. |
| */ |
| @Override |
| public Object parseNextProperty(String value, ParsePosition pos) { |
| final int start = pos.getIndex(); |
| |
| if (start > value.length()) { |
| // early exit, can't find any property here, no need to |
| // consult all the delegates. |
| return null; |
| } |
| |
| String propertyName = parsePropertyName(value, pos); |
| if (propertyName != null) { |
| Object result = getProperty(propertyName); |
| if (result != null) { |
| return result; |
| } |
| if (project != null) { |
| project.log( |
| "Property \"" + propertyName |
| + "\" has not been set", Project.MSG_VERBOSE); |
| } |
| return value.substring(start, pos.getIndex()); |
| } |
| return null; |
| } |
| |
| private String parsePropertyName(String value, ParsePosition pos) { |
| return expanders.stream() |
| .map(xp -> xp.parsePropertyName(value, pos, this)) |
| .filter(Objects::nonNull).findFirst().orElse(null); |
| } |
| |
| private Object getProperty(String propertyName) { |
| return getProperty.getProperty(propertyName); |
| } |
| } |