用Runnable接口方法进行多行程设计刚，线程功能为输出如下图形+*+**+***+****

以下是使用Runnable接口方法进行多线程设计的代码，线程功能为输出如下图形：+、*、+*、**、+**、***、+***、****。

class PrintThread implements Runnable {
    private int n;

    public PrintThread(int n) {
        this.n = n;
    }

    public void run() {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= i; j++) {
                if (j == 1 || j == i) {
                    System.out.print("+");
                } else {
                    System.out.print("*");
                }
            }
            System.out.println();
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Thread t = new Thread(new PrintThread(4));
        t.start();
    }
}