/* * Copyright 2003-2010 the original author or authors. * * 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 groovy.util.logging; import org.codehaus.groovy.ast.ClassHelper; import org.codehaus.groovy.ast.ClassNode; import org.codehaus.groovy.ast.FieldNode; import org.codehaus.groovy.ast.expr.*; import org.codehaus.groovy.transform.GroovyASTTransformationClass; import org.codehaus.groovy.transform.LogASTTransformation.LoggingStrategy; import org.objectweb.asm.Opcodes; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * This local transform adds a logging ability to your program using * java.util.logging. Every method call on a unbound variable named <i>log</i> * will be mapped to a call to the logger. For this a <i>log</i> field will be * inserted in the class. If the field already exists the usage of this transform * will cause a compilation error. The method name will be used to determine * what to call on the logger. * <pre> * log.name(exp) * </pre>is mapped to * <pre> * if (log.isLoggable(Level.NAME) { * log.name(exp) * }</pre> * Here name is a place holder for info, fine, finer, finest, config, warning, severe. * NAME is name transformed to upper case. if anything else is used it will result in * an exception at runtime. If the expression exp is a constant or only a variable access * the method call will not be transformed. But this will still cause a call on the injected * logger. * * @author Guillaume Laforge * @author Jochen Theodorou * @author Dinko Srkoc * @author Hamlet D'Arcy * @author Raffaele Cigni * @author Alberto Vilches Raton * @since 1.8.0 */ @java.lang.annotation.Documented @Retention(RetentionPolicy.SOURCE) @Target({ElementType.TYPE}) @GroovyASTTransformationClass("org.codehaus.groovy.transform.LogASTTransformation") public @interface Log { String value() default "log"; Class<? extends LoggingStrategy> loggingStrategy() default JavaUtilLoggingStrategy.class; /** * This class contains the logic of how to weave a Java Util Logging logger into the host class. */ public static class JavaUtilLoggingStrategy implements LoggingStrategy { public FieldNode addLoggerFieldToClass(ClassNode classNode, String logFieldName) { return classNode.addField(logFieldName, Opcodes.ACC_FINAL | Opcodes.ACC_TRANSIENT | Opcodes.ACC_STATIC | Opcodes.ACC_PRIVATE, new ClassNode("java.util.logging.Logger", Opcodes.ACC_PUBLIC, new ClassNode(Object.class)), new MethodCallExpression( new ClassExpression(new ClassNode("java.util.logging.Logger", Opcodes.ACC_PUBLIC, new ClassNode(Object.class))), "getLogger", new ConstantExpression(classNode.getName()))); } public boolean isLoggingMethod(String methodName) { return methodName.matches("severe|warning|info|fine|finer|finest"); } public Expression wrapLoggingMethodCall(Expression logVariable, String methodName, Expression originalExpression) { ClassNode levelClass = new ClassNode("java.util.logging.Level", 0, ClassHelper.OBJECT_TYPE); AttributeExpression logLevelExpression = new AttributeExpression( new ClassExpression(levelClass), new ConstantExpression(methodName.toUpperCase())); ArgumentListExpression args = new ArgumentListExpression(); args.addExpression(logLevelExpression); MethodCallExpression condition = new MethodCallExpression(logVariable, "isLoggable", args); return new TernaryExpression( new BooleanExpression(condition), originalExpression, ConstantExpression.NULL); } } }