对象分析工具

最新推荐文章于 2024-10-12 07:46:51 发布

原创最新推荐文章于 2024-10-12 07:46:51 发布 · 212 阅读

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对象分析工具用于java 对象内存占用分析

<!-- 对象分析工具 1 -->
        <!-- https://mvnrepository.com/artifact/org.openjdk.jol/jol-core -->
        <dependency>
            <groupId>org.openjdk.jol</groupId>
            <artifactId>jol-core</artifactId>
            <version>0.15</version>
            <scope>provided</scope>
        </dependency>
        
<!-- 对象分析工具 2 https://mvnrepository.com/artifact/com.carrotsearch/java-sizeof -->
  <dependency>
      <groupId>com.carrotsearch</groupId>
      <artifactId>java-sizeof</artifactId>
      <version>0.0.5</version>
  </dependency>

import org.openjdk.jol.info.ClassLayout;
import org.openjdk.jol.info.GraphLayout;

import java.util.HashMap;
import java.util.Map;
import org.openjdk.jol.info.ClassLayout;
import org.openjdk.jol.info.GraphLayout;

import com.carrotsearch.sizeof.RamUsageEstimator;

public class MemoryAnalysisDemo {

    public static void main(String[] args) {
        Map<String, String> phonesMap = new HashMap<>(100000);
        for (int i = 0; i < 100000; i++) {
            phonesMap.put(String.valueOf(i), "p" + i);
        }

        // 查看对象内部信息
        System.out.println(ClassLayout.parseInstance(phonesMap).toPrintable());
        // 查看对象外部信息：包括引用的对象
        // System.out.println(GraphLayout.parseInstance(phonesMap).toPrintable());
        // 查看对象占用空间总大小
        System.out.println("内存占用byte：" + GraphLayout.parseInstance(phonesMap).totalSize());

        System.out.println("内存占用byte：" + RamUsageEstimator.sizeOf(phonesMap));
        System.out.println("内存占用KB：" + RamUsageEstimator.humanSizeOf(phonesMap));
    }
    
    
}