View the size of memory occupied by an object in Java

1. maven import

<!-- https://mvnrepository.com/artifact/com.carrotsearch/java-sizeof -->
<dependency>
    <groupId>com.carrotsearch</groupId>
    <artifactId>java-sizeof</artifactId>
    <version>0.0.5</version>
</dependency>

2.

        BigDecimal b =BigDecimal.valueOf( RamUsageEstimator.sizeOf("要测量的对象"));
        BigDecimal divide = b.divide(BigDecimal.valueOf(1024 * 1024));

        log.info("DrivingController 数据大小：{} M", divide.toString());

3. Results:

###|2022-05-10 00:02:02.776|http-nio-8089-exec-3|INFO|-|-|-|ac30e9740fd142a587efeb306e162151.236.16521121208490001|***|TestController--->Data Size: 3.01990 509033203125 m