持续线程剖析

	@RequestMapping(value = {"/user/{id}"})
    @ResponseBody
    public User selectUser(@PathVariable String id) throws SQLException, IOException {
        // getUser耗时3000ms，用于模拟真实业务的耗时;
        getUser(3000);   //一般都是由于缺失对应的监控埋点，导致其耗时最终都被统计在了上一层入口 HTTP 网络请求接口/user/{id}中。
        // mysql查询调用逻辑
        selectMysql(id);	
        return new User(id, "opentelemetry");
    }
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    private void getUser(long sleepTime) {
        try {
            Thread.sleep(sleepTime);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
     private void selectMysql(String id) throws SQLException {
        Connection connection = null;
        PreparedStatement preparedStatement = null;
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        try {
            connection = dataSource.getConnection();
            
            //数据库连接相关的执行逻辑，这类逻辑在 APM 系统中都会对其进行埋点覆盖
            preparedStatement = connection.prepareStatement("SELECT name FROM mock_project_userinfo WHERE id = ?");
            preparedStatement.setString(1, "1");
            preparedStatement.executeQuery();
        } finally {
            if (preparedStatement != null) {
                preparedStatement.close();
            }
            if (connection != null) {
                connection.close();
            }
        }
    }