org.testifyproject.processor.DiscoverableProcessor Maven / Gradle / Ivy
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A module that provides Testify's annotations
/*
* Copyright 2016-2017 Testify Project.
*
* 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 org.testifyproject.processor;
import static javax.tools.StandardLocation.CLASS_OUTPUT;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.nio.file.NoSuchFileException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.Filer;
import javax.annotation.processing.Messager;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.MirroredTypesException;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.Elements;
import javax.tools.Diagnostic.Kind;
import javax.tools.FileObject;
import org.testifyproject.annotation.Discoverable;
/**
* An annotation processor implementation that generates "META-INF/services"
* provider-configuration files for classes annotated with {@link Discoverable} annotation.
*/
@SupportedAnnotationTypes("org.testifyproject.annotation.Discoverable")
public class DiscoverableProcessor extends AbstractProcessor {
@Override
public SourceVersion getSupportedSourceVersion() {
String version = System.getProperty("java.specification.version");
switch (version) {
case "1.8":
return SourceVersion.RELEASE_8;
default:
throw new AssertionError("Version '" + version + "' not supported");
}
}
@Override
public boolean process(Set annotations, RoundEnvironment roundEnv) {
if (roundEnv.processingOver()) {
return false;
}
Map> services = new HashMap<>();
Elements elements = processingEnv.getElementUtils();
roundEnv.getElementsAnnotatedWith(Discoverable.class)
.stream()
.filter(element -> element.getKind().isClass())
.forEach((element) -> {
Discoverable discoverable = element.getAnnotation(Discoverable.class);
if (discoverable != null) {
TypeElement type = (TypeElement) element;
Collection contracts = getContracts(type, discoverable);
if (!(contracts.isEmpty())) {
contracts.stream()
.map((contract) -> elements.getBinaryName(contract)
.toString())
.map((contractName) -> services.computeIfAbsent(
contractName, p -> new TreeSet<>()))
.forEach((contractNames) -> {
contractNames.add(elements.getBinaryName(type)
.toString());
});
}
}
});
Filer filer = processingEnv.getFiler();
services.entrySet().stream().forEach((entry) -> {
try {
String contract = entry.getKey();
String fileName = "META-INF/services/" + contract;
FileObject fileObject = filer.getResource(CLASS_OUTPUT, "", fileName);
try (BufferedReader reader = new BufferedReader(fileObject.openReader(false))) {
String line;
while ((line = reader.readLine()) != null) {
entry.getValue().add(line);
}
}
} catch (FileNotFoundException | NoSuchFileException e) {
} catch (IOException e) {
error(e);
}
});
services.entrySet().stream().forEach((entry) -> {
try {
String contract = entry.getKey();
String fileName = "META-INF/services/" + contract;
FileObject fileObject = filer.createResource(CLASS_OUTPUT, "", fileName);
note("Writing %s to %s", fileName, fileObject.toUri());
try (PrintWriter writer = new PrintWriter(fileObject.openWriter())) {
entry.getValue().stream().forEach((value) -> {
writer.println(value);
});
writer.flush();
}
} catch (IOException e) {
error(e);
}
});
return false;
}
Collection getContracts(TypeElement typeElement,
Discoverable discoverable) {
List typeElementList = new ArrayList<>();
try {
discoverable.value();
throw new AssertionError();
} catch (MirroredTypesException e) {
e.getTypeMirrors().stream().forEach((typeMirror) -> {
if (typeMirror.getKind() == TypeKind.VOID) {
boolean hasBaseClass = !isObject(typeElement.getSuperclass())
&& typeElement.getSuperclass().getKind() != TypeKind.NONE;
boolean hasInterfaces = !typeElement.getInterfaces().isEmpty();
if (hasBaseClass) {
typeElementList.add((TypeElement) ((DeclaredType) typeElement
.getSuperclass()).asElement());
} else if (hasInterfaces) {
typeElement.getInterfaces()
.parallelStream()
.map(p -> (TypeElement) ((DeclaredType) p).asElement())
.forEach(typeElementList::add);
} else {
error(typeElement, "Contract type could not be inferred.");
}
} else if (typeMirror instanceof DeclaredType) {
DeclaredType declaredType = (DeclaredType) typeMirror;
typeElementList.add((TypeElement) declaredType.asElement());
} else {
error(typeElement, "Invalid type specified as the contract");
}
});
}
return typeElementList;
}
boolean isObject(TypeMirror typeMirror) {
if (typeMirror instanceof DeclaredType) {
DeclaredType declaredType = (DeclaredType) typeMirror;
return ((TypeElement) declaredType.asElement())
.getQualifiedName()
.toString()
.equals("java.lang.Object");
}
return false;
}
Messager getMessanger() {
return processingEnv.getMessager();
}
void note(String message, Object... args) {
getMessanger().printMessage(Kind.NOTE, String.format(message, args));
}
void warning(String message, Object... args) {
getMessanger().printMessage(Kind.WARNING, String.format(message, args));
}
void error(Element source, String message, Object... args) {
getMessanger().printMessage(Kind.ERROR, String.format(message, args), source);
}
void error(Throwable e) {
getMessanger().printMessage(Kind.ERROR, e.getMessage());
StringWriter buffer = new StringWriter();
try (PrintWriter writer = new PrintWriter(buffer)) {
e.printStackTrace(writer);
}
getMessanger().printMessage(Kind.ERROR, buffer.toString());
}
}