001 /*
002 * Licensed under the Apache License, Version 2.0 (the "License");
003 * you may not use this file except in compliance with the License.
004 * You may obtain a copy of the License at
005 *
006 * http://www.apache.org/licenses/LICENSE-2.0
007 *
008 * Unless required by applicable law or agreed to in writing, software
009 * distributed under the License is distributed on an "AS IS" BASIS,
010 * WITHOUT WARRANTIES OR CODITIONS OF ANY KIND, either express or implied.
011 * See the License for the specific language governing permissions and
012 * limitations under the License.
013 */
014
015 package org.apache.commons.classscan.builtin;
016
017 import java.io.File;
018 import java.util.Collection;
019 import java.util.Iterator;
020
021 import org.apache.commons.classscan.ClassFile;
022 import org.apache.commons.classscan.ResourceFile;
023 import org.apache.commons.classscan.spi.model.SpiClassPathElement;
024 import org.apache.commons.classscan.spi.model.SpiMetaRegistry;
025
026 public class FileClassPathElement implements SpiClassPathElement {
027
028 private final File baseLocation;
029
030 FileClassPathElement(File baseLocation) {
031 this.baseLocation= baseLocation;
032 }
033
034 private static class FileCursor {
035 final private FileCursor prior;
036 final private File[] files;
037 private int fileIdx;
038 private final int priorLength;
039 private final StringBuilder sb;
040
041 FileCursor(FileCursor prior, File dir, StringBuilder sb) {
042 this.prior = prior;
043 files= dir.listFiles();
044 this.sb = sb;
045 if(prior!=null) {
046 sb.append('/');
047 }
048 priorLength = sb.length();
049 }
050
051 File nextFile() {
052 if(fileIdx==files.length) {
053 return null;
054 }
055 File file = files[fileIdx++];
056 sb.setLength(priorLength);
057 sb.append(file.getName());
058 return file;
059 }
060
061 FileCursor pop() {
062 return prior;
063 }
064 }
065
066 @Override
067 public Iterator<ClassFile> iterator() {
068
069 return new ClassFileIterator() {
070 StringBuilder sb = new StringBuilder();
071 FileCursor cursor= new FileCursor(null, baseLocation, sb);
072
073 ClassFile getNext() {
074 for(;;) {
075 File file = cursor.nextFile();
076 if(file == null) {
077 cursor = cursor.pop();
078 if(cursor==null) {
079 return null;
080 }
081 continue;
082 }
083
084 String path = sb.toString();
085 if(file.isDirectory()) {
086 String fileName = file.getName();
087 if( ClassNameHelper.isValidIdentifier(fileName) ) {
088 cursor= new FileCursor(cursor, file, sb);
089 }
090 continue;
091 }
092
093 if(file.canRead()) {
094 String className= ClassNameHelper.getClassNameFromFileName(file.getName());
095 if(className!=null) {
096 return new FileClassFile(file, path);
097 }
098 continue;
099 }
100 }
101 }
102 };
103 }
104
105 @Override
106 public String getLocation() {
107 return baseLocation.toURI().toString();
108 }
109
110 @Override
111 public Collection<SpiClassPathElement> getAdditionalLocations(SpiMetaRegistry registry) {
112 return null;
113 }
114
115 @Override
116 public ResourceFile getResource(String fileName) {
117 File file= new File(baseLocation, fileName);
118 if(file.isFile()) {
119 return new FileResourceFile(file, fileName);
120 }
121 return null;
122 }
123 }