直接上代碼

import java.util.Arrays;

class Processor {
    public String name() {
        return getClass().getSimpleName();
    }

    Object process(Object input) {return input;}
}

class Upcase extends Processor {
    String process(Object input) {
        return ((String)input).toUpperCase();
    }
}

class Downcase extends Processor {
    String process(Object input) {
        return ((String)input).toLowerCase();
    }
}

class Splitter extends Processor {
    String process(Object input) {
        return Arrays.toString(((String)input).split(" "));
    }
}

public class Apply {

    public static void process(Processor p, Object s) {
        System.out.println("Using Processor ----> " + p.name());
        System.out.println(p.process(s));
    }

    public static String s = "Disagreement with beliefs is by definition incorrect";
    //恒定不變的部分

    public static void main(String[] args) {
        process(new Upcase(), s);
        process(new Downcase(), s);
        process(new Splitter(), s);
    }

}

輸出

Using Processor ----> Upcase
DISAGREEMENT WITH BELIEFS IS BY DEFINITION INCORRECT（全部大寫）
Using Processor ----> Downcase
disagreement with beliefs is by definition incorrect（全部小寫）
Using Processor ----> Splitter
[Disagreement, with, beliefs, is, by, definition, incorrect]（按單詞分開(kāi)為數(shù)組）

Apply.process(Processor p，Object s) 方法 有兩個(gè)參數(shù)，第一個(gè)參數(shù)是可變部分，第二個(gè)參數(shù)是固定不變部分。
傳入方法的第一個(gè)參數(shù)，可以變化，從而帶來(lái)不同的行為（不同的處理方式）。

第二個(gè)參數(shù)
public static String s = "Disagreement with beliefs is by definition incorrect";
//恒定不變