java8特性 Optional 工具类

import lombok.Data;
import java.util.Optional;

public class qwe {
    //java fhadmin.cn
    public static void main(String[] args) {
        Student student = new Student();
        student.setReName("tom");
        Student student1 = new Student();
        student1.setName( Optional.ofNullable(student.getName()).orElseGet(student::getReName)); //
        System.out.println(student1);
    }
    @Data
    static class Student{
        String name;
        String reName;
    }
}

package com.ven.utils;
 
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
/**
 * java 8 Optional 工具类
 * @author fhadmin
 * @from fhadmin.cn
 * @ version 1.0
 */
public class OptionalUtil {
 
	/**
	 * 判断输入的字符串是否为空
	 * @param str String
	 * @return
	 */
	public static boolean isEmpty(String str){
		return  Optional.ofNullable(str).isPresent();
	}
	
	/**
	 * 判断输入的Integer是否为空
	 * @param num Integer
	 * @return
	 */
	public static boolean isEmpty(Integer num){
		return  Optional.ofNullable(num).isPresent();
	}
	/**
	 * 判断输入的Double是否为空
	 * @param dnum Double
	 * @return
	 */
	public static boolean isEmpty(Double dnum){
		return  Optional.ofNullable(dnum).isPresent();
	}
	/**
	 * 判断输入的Object是否为空
	 * @param obj
	 * @return
	 */
	public static boolean isEmpty(Object obj){
		return  Optional.ofNullable(obj).isPresent();
		
	}
	
	/**
	 * 判断输入的List是否为空,获取该对象
	 * @param obj
	 * @return
	 */
	public static Object get(Object obj){
		return Optional.ofNullable(obj).isPresent()!=false?Optional.ofNullable(obj).get():null;
		
	}
	/**
	 * 测试
	 * @param args
	 */
	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		List<String> list = new ArrayList<>();
		list.add("a");
		list.add("b");
		list.add("c");
		List<String> objList = (List<String>) OptionalUtil.get(list);
		objList.forEach(item->{System.out.println(item);});
		
		String str = null;
		System.out.println("当前对象:"+OptionalUtil.get(str));
		
		
	}
}