如何获得java对象的内存地址

        在java中内存中的对象地址是可变的，所以获得的内存地址有可能会变化。要获得内存地址也只能通过Unsafe的方法来获得，如下代码片段：

package com.bijian.study;

import java.lang.reflect.Field;
import sun.misc.Unsafe;

public class Addresser {
	
	private static Unsafe unsafe;

	static {
		try {
			Field field = Unsafe.class.getDeclaredField("theUnsafe");
			field.setAccessible(true);
			unsafe = (Unsafe) field.get(null);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static long addressOf(Object o) throws Exception {
		
		Object[] array = new Object[] { o };

		long baseOffset = unsafe.arrayBaseOffset(Object[].class);
		int addressSize = unsafe.addressSize();
		long objectAddress;
		switch (addressSize) {
		case 4:
			objectAddress = unsafe.getInt(array, baseOffset);
			break;
		case 8:
			objectAddress = unsafe.getLong(array, baseOffset);
			break;
		default:
			throw new Error("unsupported address size: " + addressSize);
		}
		return (objectAddress);
	}

	public static void main(String... args) throws Exception {
		Object mine = "Hi there".toCharArray();
		long address = addressOf(mine);
		System.out.println("Addess: " + address);

		// Verify address works - should see the characters in the array in the output
		printBytes(address, 27);
	}

	public static void printBytes(long objectAddress, int num) {
		for (long i = 0; i < num; i++) {
			int cur = unsafe.getByte(objectAddress + i);
			System.out.print((char) cur);
		}
		System.out.println();
	}
}

运行结果：

另一篇java对象内存地址的文章：Java直接内存读写。

 

文章来源：http://outofmemory.cn/code-snippet/9456/java-get-object-memory-address