groovy.util.logging.Slf4j Maven / Gradle / Ivy
/*
* Copyright 2003-2012 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 java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import groovy.lang.GroovyClassLoader;
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;
import org.objectweb.asm.Opcodes;
/**
* This local transform adds a logging ability to your program using
* LogBack logging. Every method call on a unbound variable named log
* will be mapped to a call to the logger. For this a log 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.
*
* log.name(exp)
*
is mapped to
*
* if (log.isNameLoggable() {
* log.name(exp)
* }
* Here name is a place holder for info, debug, warning, error, etc.
* 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 Hamlet D'Arcy
* @author Alberto Mijares
* @since 1.8.0
*/
@java.lang.annotation.Documented
@Retention(RetentionPolicy.SOURCE)
@Target({ElementType.TYPE})
@GroovyASTTransformationClass("org.codehaus.groovy.transform.LogASTTransformation")
public @interface Slf4j {
String value() default "log";
Class loggingStrategy() default Slf4jLoggingStrategy.class;
public static class Slf4jLoggingStrategy extends LogASTTransformation.AbstractLoggingStrategy {
private static final String LOGGER_NAME = "org.slf4j.Logger";
private static final String FACTORY_NAME = "org.slf4j.LoggerFactory";
protected Slf4jLoggingStrategy(final GroovyClassLoader loader) {
super(loader);
}
public FieldNode addLoggerFieldToClass(ClassNode classNode, String logFieldName) {
return classNode.addField(logFieldName,
Opcodes.ACC_FINAL | Opcodes.ACC_TRANSIENT | Opcodes.ACC_STATIC | Opcodes.ACC_PRIVATE,
classNode(LOGGER_NAME),
new MethodCallExpression(
new ClassExpression(classNode(FACTORY_NAME)),
"getLogger",
new ClassExpression(classNode)));
}
public boolean isLoggingMethod(String methodName) {
return methodName.matches("error|warn|info|debug|trace");
}
public Expression wrapLoggingMethodCall(Expression logVariable, String methodName, Expression originalExpression) {
MethodCallExpression condition = new MethodCallExpression(
logVariable,
"is" + methodName.substring(0, 1).toUpperCase() + methodName.substring(1, methodName.length()) + "Enabled",
ArgumentListExpression.EMPTY_ARGUMENTS);
return new TernaryExpression(
new BooleanExpression(condition),
originalExpression,
ConstantExpression.NULL);
}
}
}