unsafe

问题 I would like to get a byte[] from a float[] as quickly as possible, without looping through the whole array (via a cast, probably). Unsafe code is fine. Thanks! I am looking for a byte array 4 time longer than the float array (the dimension of the byte array will be 4 times that of the float array, since each float is composed of 4 bytes). I\'ll pass this to a BinaryWriter. EDIT : To those critics screaming \"premature optimization\": I have benchmarked this using ANTS profiler before I

问题 In the Javadoc for Object.hashCode() it states As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.) It\'s a common miconception this has something to do with the memory address but it doesn\'t as that can change without notice and the

问题 This question already has answers here : How can I get the memory location of a object in java? (4 answers) Closed 3 years ago . In Java, is there a way to get reference address, say String s = \"hello\" can I get the address of s itself , also, can I get the address of the object which reference refers to? 回答1: You can get the object index with Unsafe. Depending on how the JVM is using the memory (32-bit addresses, 32-bit index, 32-bit index with offset, 64-bit address) can affect how useful

问题 I know Java doesn\'t have pointers, but I heard that Java programs can be created with pointers and that this can be done by the few who are experts in java. Is it true? 回答1: All objects in Java are references and you can use them like pointers. abstract class Animal {... } class Lion extends Animal {... } class Tiger extends Animal { public Tiger() {...} public void growl(){...} } Tiger first = null; Tiger second = new Tiger(); Tiger third; Dereferencing a null: first.growl(); // ERROR,

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 4 years ago . I came across the sun.misc.Unsafe package the other day and was amazed at what it could do. Of course, the class is undocumented, but I was wondering if there was ever a good reason to use it. What scenarios might arise where you would need to use it? How might it be used in a