org.jboss.resteasy.microprofile.client.header.DefaultHeaderFiller Maven / Gradle / Ivy

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/*
 * JBoss, Home of Professional Open Source.
 *
 * Copyright 2021 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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.jboss.resteasy.microprofile.client.header;

import static org.jboss.resteasy.microprofile.client.header.HeaderUtils.castListToListOfStrings;
import static org.jboss.resteasy.microprofile.client.header.HeaderUtils.createMethodHandle;
import static org.jboss.resteasy.microprofile.client.header.HeaderUtils.resolveMethod;

import java.lang.invoke.MethodHandle;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.jboss.logging.Logger;

/**
 * Generates a value for dynamically computed headers (using {someMethod} as value in
 * {@link org.eclipse.microprofile.rest.client.annotation.ClientHeaderParam})
 */
class DefaultHeaderFiller implements HeaderFiller {

    private static final Logger LOGGER = Logger.getLogger(DefaultHeaderFiller.class);

    private final Method method;
    private final MethodHandle methodHandle;
    private final String headerName;
    private final boolean required;
    private final boolean withParam;

    DefaultHeaderFiller(final String methodSpecifierString,
            final String headerName,
            final boolean required,
            final Class interfaceClass,
            final Object clientProxy) {
        this.required = required;
        this.headerName = headerName;

        String methodSpecifier = methodSpecifierString.substring(1, methodSpecifierString.length() - 1);
        method = resolveMethod(methodSpecifier, interfaceClass, headerName);

        methodHandle = method.isDefault() ? createMethodHandle(method, clientProxy) : null;
        withParam = method.getParameterCount() == 1;
    }

    public List generateValues() {
        try {
            Object result;
            if (methodHandle != null) {
                if (withParam) {
                    result = methodHandle.invokeWithArguments(headerName);
                } else {
                    result = methodHandle.invokeWithArguments();
                }
            } else if (withParam) {
                result = method.invoke(null, headerName);
            } else {
                result = method.invoke(null);
            }

            if (result instanceof String[]) {
                return Arrays.asList((String[]) result);
            } else if (result instanceof List) {
                return castListToListOfStrings((List) result);
            } else {
                return Collections.singletonList(String.valueOf(result));
            }
        } catch (Throwable e) {
            if (required) {
                throw new ClientHeaderFillingException("Failed to invoke header generation method: " + method, e);
            } else {
                LOGGER.warnv(e, "Invoking header generation method {0} failed", method.toString());
            }
        }
        return Collections.emptyList();
    }
}