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/*
 * Copyright 2008-2024 Async-IO.org
 *
 * 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.
 *//* AnnotationDetector.java
  *
  * Created: 2011-10-10 (Year-Month-Day)
  * Character encoding: UTF-8
  *
  ****************************************** LICENSE *******************************************
  *
  * Copyright (c) 2011 - 2018 XIAM Solutions B.V. (http://www.xiam.nl)
  *
  * 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.atmosphere.util.annotation;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.DataInput;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.annotation.Annotation;
import java.net.JarURLConnection;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * {@code AnnotationDetector} reads Java Class File (".class") files and reports the
 * encountered annotations via a simple, developer friendly API.
 * 

* A Java Class File consists of a stream of 8-bit bytes. All 16-bit, 32-bit, and 64-bit * quantities are constructed by reading in two, four, and eight consecutive 8-bit * bytes, respectively. Multi byte data items are always stored in big-endian order, * where the high bytes come first. In the Java and Java 2 platforms, this format is * supported by interfaces {@link java.io.DataInput} and {@link java.io.DataOutput}. *

* A class file consists of a single ClassFile structure: *

 * ClassFile {
 *   u4 magic;
 *   u2 minor_version;
 *   u2 major_version;
 *   u2 constant_pool_count;
 *   cp_info constant_pool[constant_pool_count-1];
 *   u2 access_flags;
 *   u2 this_class;
 *   u2 super_class;
 *   u2 interfaces_count;
 *   u2 interfaces[interfaces_count];
 *   u2 fields_count;
 *   field_info fields[fields_count];
 *   u2 methods_count;
 *   method_info methods[methods_count];
 *   u2 attributes_count;
 *   attribute_info attributes[attributes_count];
 * }
 *
 * Where:
 * u1 unsigned byte {@link java.io.DataInput#readUnsignedByte()}
 * u2 unsigned short {@link java.io.DataInput#readUnsignedShort()}
 * u4 unsigned int {@link java.io.DataInput#readInt()}
 *
 * Annotations are stored as Attributes (i.e. "RuntimeVisibleAnnotations" and
 * "RuntimeInvisibleAnnotations").
 * 
* References: * *

* Similar projects / libraries: *

*

* All above mentioned projects make use of a byte code manipulation library (like BCEL, * ASM or Javassist). * * @author Ronald K. Muller * @since annotation-detector 3.0.0 */ public final class AnnotationDetector { /** * {@code Reporter} is the base interface, used to report the detected annotations. * Every category of annotations (i.e. Type, Field and Method) has its own specialized * interface. This enables an efficient way of reporting the detected annotations. */ public interface Reporter { /** * Return the {@code Annotation} classes which must be reported (all other * annotations are skipped). */ Class[] annotations(); } /** * A {@code Reporter} for type annotations. */ public interface TypeReporter extends Reporter { /** * This call back method is used to report an type level {@code Annotation}. * Only {@code Annotation}s, specified by {@link #annotations()} are reported! */ void reportTypeAnnotation(Class annotation, String className); } /** * A {@code Reporter} for field annotations. */ public interface FieldReporter extends Reporter { /** * This call back method is used to report an field level {@code Annotation}. * Only {@code Annotation}s, specified by {@link #annotations()} are reported! */ void reportFieldAnnotation(Class annotation, String className, String fieldName); } /** * A {@code Reporter} for method annotations. */ public interface MethodReporter extends Reporter { /** * This call back method is used to report an method level {@code Annotation}. * Only {@code Annotation}s, specified by {@link #annotations()} are reported! */ void reportMethodAnnotation(Class annotation, String className, String methodName); } private final static Logger logger = LoggerFactory.getLogger(AnnotationDetector.class); // Constant Pool type tags private static final int CP_UTF8 = 1; private static final int CP_INTEGER = 3; private static final int CP_FLOAT = 4; private static final int CP_LONG = 5; private static final int CP_DOUBLE = 6; private static final int CP_CLASS = 7; private static final int CP_STRING = 8; private static final int CP_REF_FIELD = 9; private static final int CP_REF_METHOD = 10; private static final int CP_REF_INTERFACE = 11; private static final int CP_NAME_AND_TYPE = 12; private static final int CP_METHOD_HANDLE = 15; private static final int CP_METHOD_TYPE = 16; private static final int CP_INVOKE_DYNAMIC = 18; // AnnotationElementValue private static final int BYTE = 'B'; private static final int CHAR = 'C'; private static final int DOUBLE = 'D'; private static final int FLOAT = 'F'; private static final int INT = 'I'; private static final int LONG = 'J'; private static final int SHORT = 'S'; private static final int BOOLEAN = 'Z'; // used for AnnotationElement only private static final int STRING = 's'; private static final int ENUM = 'e'; private static final int CLASS = 'c'; private static final int ANNOTATION = '@'; private static final int ARRAY = '['; // The buffer is reused during the life cycle of this AnnotationDetector instance private final ClassFileBuffer cpBuffer = new ClassFileBuffer(); // the annotation types to report, see {@link #annotations()} private final Map> annotations; private TypeReporter typeReporter; private FieldReporter fieldReporter; private MethodReporter methodReporter; // the 'raw' name of this interface or class (using '/' instead of '.' in package name) private String typeName; // Reusing the constantPool is not needed for better performance private Object[] constantPool; private String memberName; /** * Create a new {@code AnnotationDetector}, reporting the detected annotations * to the specified {@code Reporter}. */ public AnnotationDetector(final Reporter reporter) { final Class[] a = reporter.annotations(); annotations = new HashMap<>(a.length); // map "raw" type names to Class object for (Class aClass : a) { annotations.put("L" + aClass.getName().replace('.', '/') + ";", aClass); } if (reporter instanceof TypeReporter) { typeReporter = (TypeReporter) reporter; } if (reporter instanceof FieldReporter) { fieldReporter = (FieldReporter) reporter; } if (reporter instanceof MethodReporter) { methodReporter = (MethodReporter) reporter; } if (typeReporter == null && fieldReporter == null && methodReporter == null) { throw new AssertionError("No reporter defined"); } } /** * Report all Java ClassFile files available on the class path. * * @see #detect(File...) */ public void detect() throws IOException { detect(new ClassFileIterator()); } /** * Report all Java ClassFile files available on the class path within * the specified packages and sub packages. * * @see #detect(File...) */ public void detect(final String... packageNames) throws IOException { final String[] pkgNameFilter = new String[packageNames.length]; for (int i = 0; i < pkgNameFilter.length; ++i) { pkgNameFilter[i] = packageNames[i].replace('.', '/'); if (!pkgNameFilter[i].endsWith("/")) { pkgNameFilter[i] = pkgNameFilter[i].concat("/"); } } final Set files = new HashSet<>(); final Set streams = new HashSet<>(); for (final String packageName : pkgNameFilter) { final ClassLoader loader = Thread.currentThread().getContextClassLoader(); final Enumeration resourceEnum = loader.getResources(packageName); while (resourceEnum.hasMoreElements()) { final URL url = resourceEnum.nextElement(); if ("file".equals(url.getProtocol())) { final File dir = toFile(url); if (dir.isDirectory()) { files.add(dir); print("Add directory: '%s'", dir); } } else { // Resource in Jar File File jarFile; try { jarFile = toFile(((JarURLConnection) url.openConnection()).getJarFileURL()); } catch (ClassCastException cce) { try { // Weblogic crap String u = url.toExternalForm(); if (u.startsWith("zip:")) { u = u.substring(4); if (!u.startsWith("file:")) { u = "file:" + u; } u = u.substring(0, u.indexOf("!")); } jarFile = toFile(new URL(u)); } catch (Exception ex) { throw new AssertionError("Not a File: " + url.toExternalForm()); } } try { if (jarFile.isFile()) { files.add(jarFile); print("Add jar file: '%s'", jarFile); } else { final URLConnection urlConnection = url.openConnection(); if (urlConnection instanceof JarURLConnection) { loadJarContent((JarURLConnection) (url.openConnection()), packageName, streams); } else { streams.add(url.openConnection().getInputStream()); } } } catch (Exception ex) { print("Cannot load from jar file", ex); } } } } if (!files.isEmpty()) { detect(new ClassFileIterator(files.toArray(new File[0]), pkgNameFilter)); } else if (!streams.isEmpty()) { detect(new ClassFileIterator(streams.toArray(new InputStream[0]), pkgNameFilter)); } } private void loadJarContent(JarURLConnection url, String packageName, Set streams) throws IOException { // Using a JarURLConnection will load the JAR from the cache when using Webstart 1.6 // In Webstart 1.5, the URL will point to the cached JAR on the local filesystem JarFile jarFile = url.getJarFile(); Enumeration entries = jarFile.entries(); while (entries.hasMoreElements()) { JarEntry entry = entries.nextElement(); if (entry.getName().startsWith(packageName)) { streams.add(jarFile.getInputStream(entry)); } } } /** * Report all Java ClassFile files available from the specified files * and/or directories, including sub directories. *

* Note that non-class files (files, not starting with the magic number * {@code CAFEBABE} are silently ignored. */ public void detect(final File... filesOrDirectories) throws IOException { print("detectFilesOrDirectories: %s", (Object) filesOrDirectories); detect(new ClassFileIterator(filesOrDirectories, null)); } // private private File toFile(final URL url) throws MalformedURLException { // only correct way to convert the URL to a File object, also see issue #16 // Do not use URLDecoder try { return new File(url.toURI()); } catch (URISyntaxException ex) { throw new MalformedURLException(ex.getMessage()); } catch (IllegalArgumentException ex) { try { return new File(URLDecoder.decode(url.getFile(), "UTF-8")); } catch (Exception ex2) { throw new MalformedURLException(ex.getMessage()); } } } private void detect(final ClassFileIterator iterator) throws IOException { InputStream stream; while ((stream = iterator.next()) != null) { try { cpBuffer.readFrom(stream); if (hasCafebabe(cpBuffer)) { detect(cpBuffer); } // else ignore } catch (Throwable t) { // SUPPRESS CHECKSTYLE IllegalCatchCheck // catch all errors if (!iterator.isFile()) { // in case of an error we close the ZIP File here stream.close(); } } finally { // closing InputStream from ZIP Entry is handled by ZipFileIterator if (iterator.isFile()) { stream.close(); } } } } private boolean hasCafebabe(final ClassFileBuffer buffer) throws IOException { return buffer.size() > 4 && buffer.readInt() == 0xCAFEBABE; } /** * Inspect the given (Java) class file in streaming mode. */ private void detect(final DataInput di) throws IOException { readVersion(di); readConstantPoolEntries(di); readAccessFlags(di); readThisClass(di); readSuperClass(di); readInterfaces(di); readFields(di); readMethods(di); readAttributes(di, 'T', typeReporter == null); } private void readVersion(final DataInput di) throws IOException { // sequence: minor version, major version (argument_index is 1-based) if (logger.isDebugEnabled()) { print("Java Class version %2$d.%1$d", di.readUnsignedShort(), di.readUnsignedShort()); } else { di.skipBytes(4); } } private void readConstantPoolEntries(final DataInput di) throws IOException { final int count = di.readUnsignedShort(); constantPool = new Object[count]; for (int i = 1; i < count; ++i) { if (readConstantPoolEntry(di, i)) { // double slot ++i; } } } /** * Return true if a double slot is read (in case of Double or Long constant). */ private boolean readConstantPoolEntry(final DataInput di, final int index) throws IOException { final int tag = di.readUnsignedByte(); switch (tag) { case CP_UTF8: constantPool[index] = di.readUTF(); return false; case CP_INTEGER: di.skipBytes(4); // readInt() return false; case CP_FLOAT: di.skipBytes(4); // readFloat() return false; case CP_LONG: di.skipBytes(8); // readLong() return true; case CP_DOUBLE: di.skipBytes(8); // readDouble() return true; case CP_CLASS: case CP_STRING: // reference to CP_UTF8 entry. The referenced index can have a higher number! constantPool[index] = di.readUnsignedShort(); return false; case CP_REF_FIELD: case CP_REF_METHOD: case CP_REF_INTERFACE: case CP_NAME_AND_TYPE: di.skipBytes(4); // readUnsignedShort() * 2 return false; case CP_METHOD_HANDLE: di.skipBytes(3); return false; case CP_METHOD_TYPE: di.skipBytes(2); // readUnsignedShort() return false; case CP_INVOKE_DYNAMIC: di.skipBytes(4); // readUnsignedShort() * 2 return false; default: throw new ClassFormatError( "Unkown tag value for constant pool entry: " + tag); } } private void readAccessFlags(final DataInput di) throws IOException { di.skipBytes(2); // u2 } private void readThisClass(final DataInput di) throws IOException { typeName = resolveUtf8(di); print("read type '%s'", typeName); } private void readSuperClass(final DataInput di) throws IOException { di.skipBytes(2); // u2 } private void readInterfaces(final DataInput di) throws IOException { final int count = di.readUnsignedShort(); di.skipBytes(count * 2); // count * u2 } private void readFields(final DataInput di) throws IOException { final int count = di.readUnsignedShort(); print("field count = %d", count); for (int i = 0; i < count; ++i) { readAccessFlags(di); memberName = resolveUtf8(di); final String descriptor = resolveUtf8(di); readAttributes(di, 'F', fieldReporter == null); print("Field: %s, descriptor: %s", memberName, descriptor); } } private void readMethods(final DataInput di) throws IOException { final int count = di.readUnsignedShort(); { print("method count = %d", count); } for (int i = 0; i < count; ++i) { readAccessFlags(di); memberName = resolveUtf8(di); final String descriptor = resolveUtf8(di); readAttributes(di, 'M', methodReporter == null); print("Method: %s, descriptor: %s", memberName, descriptor); } } private void readAttributes(final DataInput di, final char reporterType, final boolean skipReporting) throws IOException { final int count = di.readUnsignedShort(); print("attribute count (%s) = %d", reporterType, count); for (int i = 0; i < count; ++i) { final String name = resolveUtf8(di); // in bytes, use this to skip the attribute info block final int length = di.readInt(); if (!skipReporting && ("RuntimeVisibleAnnotations".equals(name) || "RuntimeInvisibleAnnotations".equals(name))) { readAnnotations(di, reporterType); } else { print("skip attribute %s", name); di.skipBytes(length); } } } private void readAnnotations(final DataInput di, final char reporterType) throws IOException { // the number of Runtime(In)VisibleAnnotations final int count = di.readUnsignedShort(); print("annotation count (%s) = %d", reporterType, count); for (int i = 0; i < count; ++i) { final String rawTypeName = readAnnotation(di); final Class type = annotations.get(rawTypeName); if (type == null) { continue; } final String externalTypeName = typeName.replace('/', '.'); switch (reporterType) { case 'T': typeReporter.reportTypeAnnotation(type, externalTypeName); break; case 'F': fieldReporter.reportFieldAnnotation(type, externalTypeName, memberName); break; case 'M': methodReporter.reportMethodAnnotation(type, externalTypeName, memberName); break; default: throw new AssertionError("reporterType=" + reporterType); } } } private String readAnnotation(final DataInput di) throws IOException { final String rawTypeName = resolveUtf8(di); // num_element_value_pairs final int count = di.readUnsignedShort(); print("annotation elements count: %d", count); for (int i = 0; i < count; ++i) { if (logger.isDebugEnabled()) { print("element '%s'", resolveUtf8(di)); } else { di.skipBytes(2); } readAnnotationElementValue(di); } return rawTypeName; } private void readAnnotationElementValue(final DataInput di) throws IOException { final int tag = di.readUnsignedByte(); print("tag='%c'", (char) tag); switch (tag) { case BYTE: case CHAR: case DOUBLE: case FLOAT: case INT: case LONG: case SHORT: case BOOLEAN: case STRING: di.skipBytes(2); break; case ENUM: di.skipBytes(4); // 2 * u2 break; case CLASS: di.skipBytes(2); break; case ANNOTATION: readAnnotation(di); break; case ARRAY: final int count = di.readUnsignedShort(); for (int i = 0; i < count; ++i) { readAnnotationElementValue(di); } break; default: throw new ClassFormatError("Not a valid annotation element type tag: 0x" + Integer.toHexString(tag)); } } /** * Look up the String value, identified by the u2 index value from constant pool * (direct or indirect). */ private String resolveUtf8(final DataInput di) throws IOException { final int index = di.readUnsignedShort(); final Object value = constantPool[index]; final String s; if (value instanceof Integer) { s = (String) constantPool[(Integer) value]; print("resolveUtf8(%d): %d --> %s", index, value, s); } else { s = (String) value; print("resolveUtf8(%d): %s", index, s); } return s; } /** * Helper method for simple (trace) logging. */ private static void print(final String message, final Object... args) { if (logger.isDebugEnabled()) { final String logMessage; if (args.length == 0) { logMessage = message; } else { for (int i = 0; i < args.length; ++i) { // arguments may be null if (args[i] == null) { continue; } if (args[i].getClass().isArray()) { // cast back to array! Note that primitive arrays are not supported args[i] = Arrays.toString((Object[]) args[i]); } else if (args[i] == Class.class) { args[i] = ((Class) args[i]).getName(); } } logMessage = String.format(message, args); } logger.trace(logMessage); // SUPPRESS CHECKSTYLE RegexpSinglelineJavaCheck } } /** * Reclaim memory. */ public void destroy() { annotations.clear(); constantPool = null; cpBuffer.destroy(); } }





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