java 主函数中启动第二个线程，然后主函数继续向下执行

你可以采取这样的操作：

YourData yourData;
     boolean requestDeco(YourData yourData) {
                //存一份
                this.yourData = yourData;
                //交给线程处理
        new SecondThread(yourData).start();
                //返回成功
        return true;
    }

    class SecondThread extends Thread {
        YourData yourData;
        public SecondThread(YourData yourData) {
            this.yourData = yourData;
        }

        @Override
        public void run() {
            //
            // do secondThread
        }
    }