net.hasor.core.Provider Maven / Gradle / Ivy

/*
 * Copyright 2008-2009 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 net.hasor.core;
import net.hasor.utils.ExceptionUtils;
import net.hasor.utils.supplier.ClassLoaderSingleProvider;
import net.hasor.utils.supplier.SingleProvider;
import net.hasor.utils.supplier.ThreadSingleProvider;

import java.util.concurrent.Callable;
import java.util.function.Supplier;

/**
 *  提供者实现这个接口就相当于同时实现了
 *      java.util.function.Supplier
 *      javax.inject.Provider
 *      java.util.concurrent.Callable
 *  三个接口
 * @version : 2014年5月22日
 * @author 赵永春 ([email protected])
 */
public interface Provider extends Supplier, javax.inject.Provider, Callable {
    /** @return 获取对象。*/
    public default T get() {
        try {
            return this.call();
        } catch (Exception e) {
            throw ExceptionUtils.toRuntimeException(e);
        }
    }

    /**
     * Computes a result, or throws an exception if unable to do so.
     * @return computed result
     * @throws Exception if unable to compute a result
     */
    public T call() throws Exception;

    public default Provider asSingle() {
        return of(new SingleProvider<>(this));
    }

    public default Provider asThread() {
        return of(new ThreadSingleProvider<>(this));
    }

    public default Provider asLoader() {
        return of(new ClassLoaderSingleProvider<>(this));
    }

    public static  Provider of(T instance) {
        return () -> instance;
    }

    public static  Provider of(Supplier supplier) {
        return supplier::get;
    }

    public static  Provider of(javax.inject.Provider supplier) {
        return supplier::get;
    }

    public static  Provider of(Callable callable) {
        return callable::call;
    }

    public static  Provider ofs(Supplier supplier) {
        return supplier::get;
    }

    public static  Provider ofp(javax.inject.Provider supplier) {
        return supplier::get;
    }

    public static  Provider ofc(Callable callable) {
        return callable::call;
    }
}