使用unsafe获取对象出错

[SeaTalks]

我想用unsafe去allocate一块内存，然后在里面创建一个数组对象，然后等到用到的时候再取出来。
我写的Demo如下，但是总是报错，哪位大牛能帮忙解决一个，小弟不胜感激

public class Test {

	private static int byteArrayBaseOffset;

	private static Unsafe unsafe;
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		try{
			Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
			theUnsafe.setAccessible(true);
			unsafe = (Unsafe) theUnsafe.get(null);
			
			int[] test1 = new int[5];
			test1[0] =1 ;
			test1[1] =2;
			int[][] helper = new int[1][1];
			helper[0] = test1;
			@SuppressWarnings("restriction")
			int offset = unsafe.arrayBaseOffset(int[][].class);
			System.out.println("offset is :"+offset);
			long loc = unsafe.getLong(helper,offset);
			System.out.println("the address of test1 : " + loc);
			
			long baseAddress = unsafe.allocateMemory(100);
			System.out.println("baseAddress is :"+baseAddress);
			int headersize = unsafe.arrayBaseOffset(int[].class);
			
			//copy the header of test1 and the first element to allocated memory
			for(int i =0;i<headersize+4;i++){
				unsafe.putByte(baseAddress+i, unsafe.getByte(test1, i));
			}
			
			
			Object[] array = new Object[1];
			int baseOffSet = unsafe.arrayBaseOffset(Object[].class);
			System.out.println("baseOffset of a array is :"+baseOffSet);
			
			//put the pointer of test1 into array[0] , it equals to "array[0] = test1;"
			unsafe.putLong(array, baseOffSet, loc);	
			System.out.println("the first element of test1 :"+ ((int[])unsafe.getObject(array, baseOffSet))[0]);
			
			//put the pointer of int array instance which we created in allocated memory into array[0]
			unsafe.putLong(array, baseOffSet, baseAddress);
			int[] t2 = (int[]) unsafe.getObject(array, baseOffSet);
			System.out.println("the first elment of t2:"+t2[0]);
			
	 		unsafe.freeMemory(baseAddress);
		}catch(SecurityException s){
			System.out.println("Security Exception occurred,message is :" + s.getMessage());
		}catch(NoSuchFieldException n){
			System.out.println("NoSuchField Exception occurred,message is :" + n.getMessage());
		}catch(IllegalArgumentException i){
			System.out.println("Illegal argument Exception occurred,message is :" + i.getMessage());
		}catch(IllegalAccessException ia){
			System.out.println("Illegal access Exception occurred,message is :" + ia.getMessage());
		}
	}

}

执行结果如下：

[乐之者v]

是不是环境问题？我的跑出来没错啊。 offset is :12 the address of test1 : 4567018312 baseAddress is :54279528 baseOffset of a array is :12 the first element of test1 :1 the first elment of t2:1

[SeaTalks]

引用 1 楼 sinat_32502451 的回复:

是不是环境问题？我的跑出来没错啊。 offset is :12 the address of test1 : 4567018312 baseAddress is :54279528 baseOffset of a array is :12 the first element of test1 :1 the first elment of t2:1

你的是32位的机器吧，好像32位是可以的。但我是64位的

[SeaTalks]

自己能顶帖吗，试试

[woshimike]

jdk 1.8 win7 64位 表示运行正常

[SeaTalks]

引用 4 楼 woshimike 的回复:

jdk 1.8 win7 64位 表示运行正常

我换成jdk1.8试试

[SeaTalks]

引用 4 楼 woshimike 的回复:

jdk 1.8 win7 64位 表示运行正常

换成jdk1.8后可以了，但是jdk1.6和jdk1.7都不行，有谁知道原因吗？

[sky_08_06_02]

[SeaTalks]

是由于Compressed oops的问题引起的 如果有兴趣的可以去看这里