content: /*
   *  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.taskdefs.condition;
  
  import java.io.IOException;
  import java.util.Iterator;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.types.Resource;
  import org.apache.tools.ant.types.ResourceCollection;
  import org.apache.tools.ant.types.resources.Union;
  import org.apache.tools.ant.util.ResourceUtils;
  
  /**
   * Compares resources for equality based on size and content.
   * All resources specified must match; no resource collections
   * specified is an error condition; if resource collections are
   * specified, but yield fewer than two elements, the condition
   * evaluates to <code>true</code>.
   * @since Ant 1.7
   */
  public class ResourcesMatch implements Condition {
  
      private Union resources = null;
      private boolean asText = false;
  
      /**
       * Set whether to treat resources as if they were text files,
       * ignoring line endings.
       * @param asText whether to ignore line endings.
       */
      public void setAsText(boolean asText) {
          this.asText = asText;
      }
  
      /**
       * Add a resource collection.
       * @param rc the resource collection to add.
       */
      public void add(ResourceCollection rc) {
          if (rc == null) {
              return;
          }
          resources = resources == null ? new Union() : resources;
          resources.add(rc);
      }
  
      /**
       * Verify that all resources match.
       * @return true if all resources are equal.
       * @exception BuildException if there is an error.
       */
      @Override
      public boolean eval() throws BuildException {
          if (resources == null) {
              throw new BuildException(
                  "You must specify one or more nested resource collections");
          }
          if (resources.size() > 1) {
              Iterator<Resource> i = resources.iterator();
              Resource r1 = i.next();
              Resource r2;
  
              while (i.hasNext()) {
                  r2 = i.next();
                  try {
                      if (!ResourceUtils.contentEquals(r1, r2, asText)) {
                          return false;
                      }
                  } catch (IOException ioe) {
                      throw new BuildException("when comparing resources "
                          + r1.toString() + " and " + r2.toString(), ioe);
                  }
                  r1 = r2;
              }
          }
          return true;
      }
  }
  