map源码解析

public static <K extends Comparable<? super K>, V> Comparator<Map.Entry<K,V>> comparingByKey() {
        return (Comparator<Map.Entry<K, V>> & Serializable)
            (c1, c2) -> c1.getKey().compareTo(c2.getKey());
    }

https://segmentfault.com/q/1010000018152204/a-1020000018154699

package com.boss.cxgovac.galdatacarry.core;

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class CollectionTest {
	
    public static String datafile = "D:\\out.txt";
    
    interface Function{
        void func(String s);
    }
    
    public static Function get(){
        return (Function & Serializable)
        		( (s)->System.out.println(s) );
    }
    
    public static void main(String[] args) throws IOException {
        Function function = get();
        ObjectOutputStream out = new ObjectOutputStream(
                                  new BufferedOutputStream(
                                   new FileOutputStream(datafile)));
        out.writeObject(function);
        System.out.println("输出完成...");
        out.close();
    }


}