/*
* Copyright 2013 Decebal Suiu
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with
* the License. You may obtain a copy of the License in the LICENSE file, or 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 ro.fortsoft.pf4j;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.RoundEnvironment;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.tools.Diagnostic.Kind;
import javax.tools.FileObject;
import javax.tools.StandardLocation;
/**
* @author Decebal Suiu
*/
public class ExtensionsIndexer extends AbstractProcessor {
public static final String EXTENSIONS_RESOURCE = "META-INF/extensions.idx";
private List<TypeElement> extensions = new ArrayList<TypeElement>();
@Override
public SourceVersion getSupportedSourceVersion() {
return SourceVersion.latest();
}
@Override
public Set<String> getSupportedAnnotationTypes() {
Set<String> annotationTypes = new HashSet<String>();
annotationTypes.add(Extension.class.getName());
return annotationTypes;
}
@Override
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
if (roundEnv.processingOver()) {
return false;
}
for (Element element : roundEnv.getElementsAnnotatedWith(Extension.class)) {
if (!(element instanceof TypeElement)) {
continue;
}
TypeElement typeElement = (TypeElement) element;
String message = "Extension found in " + processingEnv.getElementUtils().getBinaryName(typeElement).toString();
processingEnv.getMessager().printMessage(Kind.NOTE, message);
extensions.add(typeElement);
}
/*
if (!roundEnv.processingOver()) {
return false;
}
*/
write();
return false;
// return true; // no further processing of this annotation type
}
private void write() {
Set<String> entries = new HashSet<String>();
for (TypeElement typeElement : extensions) {
entries.add(processingEnv.getElementUtils().getBinaryName(typeElement).toString());
}
read(entries); // read old entries
write(entries); // write entries
}
private void write(Set<String> entries) {
try {
FileObject file = processingEnv.getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", EXTENSIONS_RESOURCE);
Writer writer = file.openWriter();
for (String entry : entries) {
writer.write(entry);
writer.write("\n");
}
writer.close();
} catch (FileNotFoundException e) {
// it's the first time, create the file
} catch (IOException e) {
processingEnv.getMessager().printMessage(Kind.ERROR, e.toString());
}
}
private void read(Set<String> entries) {
try {
FileObject file = processingEnv.getFiler().getResource(StandardLocation.CLASS_OUTPUT, "", EXTENSIONS_RESOURCE);
readIndex(file.openReader(true), entries);
} catch (FileNotFoundException e) {
} catch (IOException e) {
// thrown by Eclipse JDT when not found
} catch (UnsupportedOperationException e) {
// java6 does not support reading old index files
}
}
public static void readIndex(Reader reader, Set<String> entries) throws IOException {
BufferedReader bufferedReader = new BufferedReader(reader);
String line;
while ((line = bufferedReader.readLine()) != null) {
entries.add(line);
}
reader.close();
}
}