代码反思(1)

1、for循环中需要睡眠等待

(1) 利用continue

package org.samuel.ch01;

import java.util.Arrays;
import java.util.List;
import java.util.Random;

public class Processor {
    List<String> tasks;
    Random random;
    int size;
    
    public Processor(List<String> tasks) {
        this.tasks = tasks;
        this.random = new Random();
        this.size = tasks.size();
    }
    
    public void process() {
        for (int i = 0; i < size; ) {
            if (!isRunnable()) {
                try {
                    System.out.println("System is busy now...");
                    Thread.sleep(1000);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
                continue;
            }
            String task = tasks.get(i);
            doTask(task);
            i++;
        }
    }

　　private boolean isRunnable() {
        return random.nextInt() % 2 == 0;
    }
    
    private void doTask(String task) {
        System.out.println("Finish task : " + task);
    }
    
    public static void main(String[] args) {
        List<String> tasks = Arrays.asList("samuel", "lin", "by", "badboyby", "linlin");
        Processor processor = new Processor(tasks);
        processor.process();
    }
}

(2) 使用while循环

package org.samuel.ch01;

import java.util.Arrays;
import java.util.List;
import java.util.Random;

public class AdvancedProcessor {
    List<String> tasks;
    Random random;
    int size;
    
    public AdvancedProcessor(List<String> tasks) {
        this.tasks = tasks;
        this.random = new Random();
        this.size = tasks.size();
    }

    public void process() {
        for (String task : tasks) {
            while(!isRunnable()) {
                try {
                    System.out.println("System is busy now...");
                    Thread.sleep(1000);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                }
            }
            doTask(task);
        }
    }

　　private boolean isRunnable() {
        return random.nextInt() % 2 == 0;
    }
    
    private void doTask(String task) {
        System.out.println("Finish task : " + task);
    }
    
    public static void main(String[] args) {
        List<String> tasks = Arrays.asList("samuel", "lin", "by", "badboyby", "linlin");
        AdvancedProcessor processor = new AdvancedProcessor(tasks);
        processor.process();
    }
}

对比两种方案，从代码逻辑来看，第2种方案更容易理解。第一种方案的continue跳转以及for循环i++的位置，比较晦涩。