printspooler.java

源码为科学出版社出版的英文<java设计模式>(影印版)所用的所有例子程序

public class PrintSpooler {
    private static PrintSpooler spooler;
    private PrintSpooler() {
    }
    public static synchronized PrintSpooler getSpooler() {
        if (spooler == null)
            spooler =  new PrintSpooler();
        return spooler;
    }
    public void print(String s) {
        System.out.println(s);
    }
}