使用JvisualVM排查OOM

1 测试环境

使用JDK1.8

package jvm.oom;

import java.util.ArrayList;

public class TestOOM {
    static class OOMObject {
        private String content;

        public OOMObject(String content) {
            this.content = content;
        }
    }

    public static void main(String[] args) {
        ArrayList<OOMObject> list = new ArrayList<>();
        int a = 1;
        while (true) {
            list.add(new OOMObject(String.valueOf(a ++)));
        }
    }
}

配置JVM参数：

-Xms2m	// JVM启动时堆内存的初始化大小
-Xmx4m	// 设置堆内存最大值
-XX:+HeapDumpOnOutOfMemoryError	// 表示出现OOM异常后，生成堆快照hprof文件
-XX:HeapDumpPath=d:\jvmtest	// 设置堆快照hprof文件存储的位置

2 运行

java.lang.OutOfMemoryError: Java heap space
Dumping heap to d:\jvmtest ...
Unable to create d:\jvmtest: File exists
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
	at java.util.Arrays.copyOf(Arrays.java:3210)
	at java.util.Arrays.copyOf(Arrays.java:3181)
	at java.util.ArrayList.grow(ArrayList.java:261)
	at java.util.ArrayList.ensureExplicitCapacity(ArrayList.java:235)
	at java.util.ArrayList.ensureCapacityInternal(ArrayList.java:227)
	at java.util.ArrayList.add(ArrayList.java:458)
	at jvm.oom.TestOOM.main(TestOOM.java:18)

Process finished with exit code 1