Java tutorial
/* * 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.devtools.j2objc.util; import com.google.devtools.j2objc.file.InputFile; import com.google.j2objc.annotations.ReflectionSupport; import java.io.IOException; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.objectweb.asm.AnnotationVisitor; import org.objectweb.asm.ClassReader; import org.objectweb.asm.ClassVisitor; import org.objectweb.asm.Opcodes; /** * Looks up package specific attributes by looking up and parsing package-info java or class files. */ public class PackageInfoLookup { private final Map<String, PackageData> map = new HashMap<>(); private final FileUtil fileUtil; private static final String REFLECTION_SUPPORT_REGEX = "@(?:com\\.google\\.j2objc\\.annotations\\.)?ReflectionSupport\\s*" + "\\([^\\)]*(FULL|NATIVE_ONLY)\\s*\\)"; // Avoid allocating a new PackageData instance for packages with no attributes. private static final PackageData EMPTY_DATA = new PackageData(new PackageDataBuilder()); public PackageInfoLookup(FileUtil fileUtil) { this.fileUtil = fileUtil; } private static class PackageData { private final String objectiveCName; private final boolean parametersAreNonnullByDefault; private final ReflectionSupport.Level reflectionSupportLevel; private PackageData(PackageDataBuilder builder) { this.objectiveCName = builder.objectiveCName; this.parametersAreNonnullByDefault = builder.parametersAreNonnullByDefault; this.reflectionSupportLevel = builder.reflectionSupportLevel; } } private static class PackageDataBuilder { private boolean isEmpty = true; private String objectiveCName = null; private boolean parametersAreNonnullByDefault = false; private ReflectionSupport.Level reflectionSupportLevel; private void setObjectiveCName(String objectiveCName) { this.objectiveCName = objectiveCName; isEmpty = false; } private void setParametersAreNonnullByDefault() { parametersAreNonnullByDefault = true; isEmpty = false; } private void setReflectionSupportLevel(ReflectionSupport.Level level) { this.reflectionSupportLevel = level; isEmpty = false; } private PackageData build() { return isEmpty ? EMPTY_DATA : new PackageData(this); } } public String getObjectiveCName(String packageName) { return getPackageData(packageName).objectiveCName; } public boolean hasParametersAreNonnullByDefault(String packageName) { return getPackageData(packageName).parametersAreNonnullByDefault; } public ReflectionSupport.Level getReflectionSupportLevel(String packageName) { return getPackageData(packageName).reflectionSupportLevel; } private PackageData getPackageData(String packageName) { PackageData result = map.get(packageName); if (result == null) { result = findPackageData(packageName); map.put(packageName, result); } return result; } private PackageData findPackageData(String packageName) { try { String fileName = packageName + ".package-info"; // First look on the sourcepath. InputFile sourceFile = fileUtil.findOnSourcePath(fileName); if (sourceFile != null) { return parseDataFromSourceFile(sourceFile); } // Then look on the classpath. InputFile classFile = fileUtil.findOnClassPath(fileName); if (classFile != null) { return parseDataFromClassFile(classFile); } } catch (IOException e) { // Continue with no package-info data. } return EMPTY_DATA; } /** * Return true if pkgInfo has the specified annotation. * * @param pkgInfo package-info source code * @param annotation fully qualified name of the annotation */ private static boolean hasAnnotation(String pkgInfo, String annotation) { if (!annotation.contains(".")) { ErrorUtil.warning(annotation + " is not a fully qualified name"); } if (pkgInfo.contains("@" + annotation)) { return true; } int idx = annotation.lastIndexOf("."); String annotationPackageName = annotation.substring(0, idx); String annotationSimpleName = annotation.substring(idx + 1); if (pkgInfo.contains("@" + annotationSimpleName)) { String importRegex = "import\\s*" + annotationPackageName + "(\\.\\*|\\." + annotationSimpleName + ")"; Pattern p = Pattern.compile(importRegex); Matcher m = p.matcher(pkgInfo); if (m.find()) { return true; } } return false; } private PackageData parseDataFromSourceFile(InputFile file) throws IOException { PackageDataBuilder builder = new PackageDataBuilder(); String pkgInfo = fileUtil.readFile(file); // @ObjectiveCName int i = pkgInfo.indexOf("@ObjectiveCName"); if (i == -1) { i = pkgInfo.indexOf("@com.google.j2objc.annotations.ObjectiveCName"); } if (i > -1) { // Extract annotation's value string. i = pkgInfo.indexOf('"', i + 1); if (i > -1) { int j = pkgInfo.indexOf('"', i + 1); if (j > -1) { builder.setObjectiveCName(pkgInfo.substring(i + 1, j)); } } } // @ParametersAreNonnullByDefault if (pkgInfo.contains("@ParametersAreNonnullByDefault") || pkgInfo.contains("@javax.annotation.ParametersAreNonnullByDefault")) { builder.setParametersAreNonnullByDefault(); } // @ReflectionSupportLevel if (hasAnnotation(pkgInfo, "com.google.j2objc.annotations.ReflectionSupport")) { Pattern p = Pattern.compile(REFLECTION_SUPPORT_REGEX); Matcher m = p.matcher(pkgInfo); if (m.find()) { String level = m.group(1); builder.setReflectionSupportLevel(ReflectionSupport.Level.valueOf(level)); } else { ErrorUtil.warning("Invalid ReflectionSupport Level in " + file.getUnitName()); } } return builder.build(); } private PackageData parseDataFromClassFile(InputFile file) throws IOException { PackageDataBuilder builder = new PackageDataBuilder(); ClassReader classReader = new ClassReader(file.getInputStream()); classReader.accept(new ClassVisitor(Opcodes.ASM5) { @Override public AnnotationVisitor visitAnnotation(String desc, boolean visible) { if (desc.equals("Lcom/google/j2objc/annotations/ObjectiveCName;")) { return new AnnotationVisitor(Opcodes.ASM5) { @Override public void visit(String name, Object value) { if (name.equals("value")) { builder.setObjectiveCName(value.toString()); } } }; } else if (desc.equals("Ljavax/annotation/ParametersAreNonnullByDefault;")) { builder.setParametersAreNonnullByDefault(); } else if (desc.equals("Lcom/google/j2objc/annotations/ReflectionSupport;")) { return new AnnotationVisitor(Opcodes.ASM5) { @Override public void visitEnum(String name, String desc, String value) { if (desc.equals("Lcom/google/j2objc/annotations/ReflectionSupport$Level;") && name.equals("value")) { builder.setReflectionSupportLevel(ReflectionSupport.Level.valueOf(value)); } } }; } return null; } }, 0); return builder.build(); } }