sun.misc.Unsafe类
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package org.jiucheng.util;
import java.lang.reflect.Field;
import org.jiucheng.exception.UncheckedException;
public class Unsafe {
private static sun.misc.Unsafe UNSAFE;
public static sun.misc.Unsafe getUnsafe() {
if(null != UNSAFE) {
return UNSAFE;
}
try {
Field f = sun.misc.Unsafe.class.getDeclaredField("theUnsafe");
f.setAccessible(true);
UNSAFE = (sun.misc.Unsafe) f.get(null);
return UNSAFE;
} catch (NoSuchFieldException e) {
throw new UncheckedException(e);
} catch (SecurityException e) {
throw new UncheckedException(e);
} catch (IllegalArgumentException e) {
throw new UncheckedException(e);
} catch (IllegalAccessException e) {
throw new UncheckedException(e);
}
}
/**
* 实例化一个对象(绕过构造器)
* @param clazz
* @return
*/
public static <T> T allocateInstance(Class<T> clazz) {
try {
return (T) getUnsafe().allocateInstance(clazz);
} catch (InstantiationException e) {
throw new UncheckedException(e);
}
}
public static int arrayBaseOffset(Class<?> clazz) {
return getUnsafe().arrayBaseOffset(clazz);
}
}
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