复制代码代码如下：
导入java.util.concurrent.semaphore;
公共类三项{
公共静态void main（string [] args）抛出InterruptedException {
信号sempa =新信号（1）;
信号sempb =新信号（0）;
信号sempc =新信号（0）;
int n = 100;
线程threada = new printThread（n，sempa，sempb，“ a”）;
thread threadB = new printThread（n，sempb，sempc，“ b”）;
thread threadC = new printThread（n，sempc，sempa，“ c”）;
threada.start（）;
threadB.start（）;
threadc.start（）;
}
静态类PrintThread扩展了线程{
int n;
信号函数cursemp;
信号sextsemp;
字符串名称;
public printThread（int n，信号函数cursemp，信号semaphore sempsemp，字符串名称）{
n = n;
this.cursemp = cursemp;
this.nextSemp = nextSemp;
this.name = name;
}
public void run（）{
for（int i = 0; i <n; ++ i）{
尝试 {
cursemp.Acquire（）;
system.out.println（name）;
NextSemp.Release（）;
} catch（InterruptedException e）{
thread.currentThread（）。interrupt（）;
}
}
}
}
}