org.springframework.cloud.sleuth.annotation.SleuthAnnotationUtils.java Source code

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Here is the source code for org.springframework.cloud.sleuth.annotation.SleuthAnnotationUtils.java

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/*
 * Copyright 2013-2016 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 org.springframework.cloud.sleuth.annotation;

import java.lang.annotation.Annotation;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.annotation.AnnotationUtils;

/**
 * Utility class that can verify whether the method is annotated with
 * the Sleuth annotations.
 *
 * @author Christian Schwerdtfeger
 * @since 1.2.0
 */
class SleuthAnnotationUtils {

    private static final Log log = LogFactory.getLog(MethodHandles.lookup().lookupClass());

    static boolean isMethodAnnotated(Method method) {
        return findAnnotation(method, NewSpan.class) != null || findAnnotation(method, ContinueSpan.class) != null;
    }

    static boolean hasAnnotatedParams(Method method, Object[] args) {
        return !findAnnotatedParameters(method, args).isEmpty();
    }

    static List<SleuthAnnotatedParameter> findAnnotatedParameters(Method method, Object[] args) {
        Annotation[][] parameters = method.getParameterAnnotations();
        List<SleuthAnnotatedParameter> result = new ArrayList<>();
        int i = 0;
        for (Annotation[] parameter : parameters) {
            for (Annotation parameter2 : parameter) {
                if (parameter2 instanceof SpanTag) {
                    result.add(new SleuthAnnotatedParameter(i, (SpanTag) parameter2, args[i]));
                }
            }
            i++;
        }
        return result;
    }

    /**
     * Searches for an annotation either on a method or inside the method parameters
     */
    static <T extends Annotation> T findAnnotation(Method method, Class<T> clazz) {
        T annotation = AnnotationUtils.findAnnotation(method, clazz);
        if (annotation == null) {
            try {
                annotation = AnnotationUtils.findAnnotation(
                        method.getDeclaringClass().getMethod(method.getName(), method.getParameterTypes()), clazz);
            } catch (NoSuchMethodException | SecurityException e) {
                if (log.isDebugEnabled()) {
                    log.debug("Exception occurred while tyring to find the annotation", e);
                }
            }
        }
        return annotation;
    }
}