com.google.gwt.dev.resource.impl.FileResource Maven / Gradle / Ivy
/*
* Copyright 2008 Google Inc.
*
* 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 com.google.gwt.dev.resource.impl;
import com.google.gwt.thirdparty.guava.common.collect.MapMaker;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.concurrent.ConcurrentMap;
/**
* Represents a resource contained in a directory on a file system.
* The class is immutable and automatically interned.
*/
public class FileResource extends AbstractResource {
/*
* The #equals and #hashCode is locked to work on identities by the base class Resource.
* Without interning, it would be impractical to use this class as a key in a map.
*/
private static final ConcurrentMap canonicalFileResources =
new MapMaker().weakValues().makeMap();
public static FileResource of(String abstractPathName, File file) {
String key = abstractPathName + "@" + file.getAbsolutePath();
FileResource sample = new FileResource(abstractPathName, file);
FileResource canonical = canonicalFileResources.putIfAbsent(key, sample);
return (canonical == null) ? sample : canonical;
}
private final String abstractPathName;
private final File file;
private FileResource(String abstractPathName, File file) {
this.abstractPathName = abstractPathName;
this.file = file;
}
@Override
public long getLastModified() {
return file.lastModified();
}
@Override
public String getLocation() {
return file.toURI().toString();
}
@Override
public String getPath() {
return abstractPathName;
}
@Override
public InputStream openContents() throws IOException {
return new FileInputStream(file);
}
}