结论：

1、线程池队列容量满了后，迅速扩容至maxPoolSize

2、队列满后，再进来任务，则主线程执行任务

3、任务执行完后，等待（keepAliveSeconds），主线程数然后恢复至corePoolSize

1、线程池初始化代码

    @Bean
    public ThreadPoolTaskExecutor getCareRightsExecutor() {
        final ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(10);
        executor.setMaxPoolSize(40);
        executor.setKeepAliveSeconds(60);
        executor.setThreadNamePrefix("care-right-");
        executor.setQueueCapacity(965);
        // 等待所有任务结果候再关闭线程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        executor.setAwaitTerminationSeconds(60);
        // 定义拒绝策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 初始化线程池, 初始化 core 线程
        executor.initialize();
        return executor;
    }

2、测试代码

    @Resource
    private ThreadPoolTaskExecutor getCareRightsExecutor;

    @Test
    void testThread() throws InterruptedException {
        final Logger logP = LoggerFactory.getLogger(this.getClass());
        for (int i = 0; i < 10000; i++) {
            getCareRightsExecutor.execute(() -> {
                try {
                    logP.info("队列长度：" + getCareRightsExecutor.getQueueSize());
                    Thread.sleep(RandomUtil.randomLong(1100, 2000));
                } catch (final InterruptedException e) {
                    throw new RuntimeException(e);
                }

            });
        }

        //Thread.sleep(100000000);

    }

打印日志