java8接口默认方法二

亦凉 2022-09-26 03:06 140阅读 0赞

**使用函数式接口Supplier来实例化接口默认方法,Supplier对于给定的泛型类型产生一个实例,不需要任何参数。**

**接口：DefaultMethodInterface**

package com.ven.java8.defaultmethod.Inteface;
    
    /**
     * jva8接口默认方法
     * @author xiaowen0623
     *
     */
    public interface DefaultMethodInterface {
    	/**
    	 * 接口静态变量
    	 */
    	public static final String TYPE="JAVA8";
    	
    	/**
    	 * 接口静态变量
    	 */
    	public static final String ZW="JAVA WEB开发工程师";
    	/**
    	 * 接口方法
    	 * 
    	 * @param userName
    	 */
    	public void execute(String userName);
    
    	/**
    	 * 默认方法
    	 * 
    	 * @param userName
    	 */
    	default void learn(String userName) {
    		System.out.println(userName + "正在学习"+TYPE+"。。。。。。");
    	}
    
    	/**
    	 * 默认的静态方法
    	 * 
    	 * @param userName
    	 * @return
    	 */
    	public static String learnStr(String userName) { 
    		String result = userName + " " + "是一名"+ZW;
    		return result;
    
    	};
    
    }

接口工厂：

package com.ven.java8.defaultmethod.Inteface;
    
    import java.util.function.Supplier;
    
    /**
     * 接口工厂
     * 使用Supplier供应接口产生一个给定泛型的对象
     * @author xiaowen0623
     *
     */
    public interface DefaulableFactory {
        
    	/**
    	 * 通过函数接口Defaulable的实例
    	 * @param supplier
    	 * @return
    	 */
    	static DefaultMethodInterface create(Supplier<DefaultMethodInterface> supplier){
    		return supplier.get();
    	};	
    }

**Supplier接口源代码：**

/*
     * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
     * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     *
     */
    package java.util.function;
    
    /**
     * Represents a supplier of results.
     *
     * <p>There is no requirement that a new or distinct result be returned each
     * time the supplier is invoked.
     *
     * <p>This is a <a href="package-summary.html">functional interface</a>
     * whose functional method is {@link #get()}.
     *
     * @param <T> the type of results supplied by this supplier
     *
     * @since 1.8
     */
    @FunctionalInterface
    public interface Supplier<T> {
    
        /**
         * Gets a result.
         *
         * @return a result
         */
        T get();
    }

测试：

package com.ven.java8.defaultmethod.Inteface.test;
    
    import com.ven.java8.defaultmethod.Inteface.DefaulableFactory;
    import com.ven.java8.defaultmethod.Inteface.DefaultMethodImpl;
    import com.ven.java8.defaultmethod.Inteface.DefaultMethodInterface;
    
    /**
     * 测试接口默认方法
     * @author xiaowen0623
     *
     */
    public class TestFactory {
    
    	public static void main(String[] args) {
    		//使用DefaultMethodImpl::new 使用java8新的方法引用方式
    		DefaultMethodInterface d = DefaulableFactory.create(DefaultMethodImpl::new);
    	    d.execute("xiaowen");
    	}
    }