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A JSR-330 spec compliant dependency injection framework.
There is a newer version: 2.0.0
/*
 * Copyright (C) 2016-2017 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 io.github.pustike.inject;

import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.util.Enumeration;
import java.util.Map;
import java.util.Objects;
import java.util.Properties;
import javax.inject.Named;

import io.github.pustike.inject.bind.Binder;

/**
 * Utility methods for use with {@code @}{@link Named}.
 *
 * This class is borrowed from Guice project's
 * 
 * Names class with few modifications.
 * 
 * @author [email protected] (Bob Lee)
 */
public final class Names {

    private Names() {
    }

    /**
     * Creates a {@link Named} annotation with {@code name} as the value.
     * @param name the named value
     * @return the named instance
     */
    public static Named named(String name) {
        return new NamedImpl(name);
    }

    /**
     * Creates a constant binding to {@code @Named(key)} for each entry in {@code keyValueMap}.
     * @param binder      the binder used to create bindings
     * @param keyValueMap the map with [key, value] entries to bind
     */
    public static void bindProperties(Binder binder, Map keyValueMap) {
        for (Map.Entry entry : keyValueMap.entrySet()) {
            binder.bind(String.class).named(entry.getKey()).toInstance(entry.getValue());
        }
    }

    /**
     * Creates a constant binding to {@code @Named(key)} for each property. This
     * method binds all properties including those inherited from {@link Properties#defaults defaults}.
     * @param binder     the binder used to create bindings
     * @param properties the properties object with [key, value] entries to bind
     */
    public static void bindProperties(Binder binder, Properties properties) {
        // use enumeration to include the default properties
        for (Enumeration e = properties.propertyNames(); e.hasMoreElements(); ) {
            String propertyName = (String) e.nextElement();
            String value = properties.getProperty(propertyName);
            binder.bind(String.class).named(propertyName).toInstance(value);
        }
    }

    private static class NamedImpl implements Named, Serializable {
        private static final long serialVersionUID = 0;
        private final String value;

        NamedImpl(String value) {
            this.value = Objects.requireNonNull(value, "name");
        }

        @Override
        public String value() {
            return this.value;
        }

        @Override
        public int hashCode() {
            // This is specified in java.lang.Annotation.
            return (127 * "value".hashCode()) ^ value.hashCode();
        }

        @Override
        public boolean equals(Object o) {
            if (!(o instanceof Named)) {
                return false;
            }
            Named other = (Named) o;
            return value.equals(other.value());
        }

        @Override
        public String toString() {
            return "@" + Named.class.getName() + "(value=" + value + ")";
        }

        @Override
        public Class annotationType() {
            return Named.class;
        }
    }
}