问使用Java unsafe将char数组指向内存位置

EN

package testreflect;

import java.lang.reflect.Field;

import sun.misc.Unsafe;

public class App {
    public static void main(String[] args) throws Exception {
        Field field = Unsafe.class.getDeclaredField("theUnsafe");
        field.setAccessible(true);
        Unsafe UNSAFE = (Unsafe) field.get(null);

        char[] sourceChars = new char[] { 'b', 'a', 'r', 0x2018 };

        // Encoding to a byte array; asBytes would be an LMDB entry
        byte[] asBytes = new byte[sourceChars.length * 2];
        UNSAFE.copyMemory(sourceChars, 
                UNSAFE.arrayBaseOffset(sourceChars.getClass()), 
                asBytes, 
                UNSAFE.arrayBaseOffset(asBytes.getClass()), 
                sourceChars.length*(long)UNSAFE.arrayIndexScale(sourceChars.getClass()));

        // Copying the byte array to the char array works, but is there a way to
        // have the char array simply point to the byte array without copying?
        char[] test = new char[sourceChars.length];
        UNSAFE.copyMemory(asBytes, 
                UNSAFE.arrayBaseOffset(asBytes.getClass()), 
                test, 
                UNSAFE.arrayBaseOffset(test.getClass()), 
                asBytes.length*(long)UNSAFE.arrayIndexScale(asBytes.getClass()));

        // Allocate a String object, but set its underlying 
        // byte array manually to avoid the extra memory copy   
        long stringOffset = UNSAFE.objectFieldOffset(String.class.getDeclaredField("value"));
        String stringTest = (String) UNSAFE.allocateInstance(String.class);
        UNSAFE.putObject(stringTest, stringOffset, test);
        System.out.println(stringTest);
    }
}