Java: How do I get values from the other programs?

Question

To make the question more understandable, there is a software called CheatEngine, and basically what it does is, it collects all the bytes of the software that you're trying to work with and you can select any of those and change the value.

For example you want to change the score of any game. You can search for the value of the current score, and change it to what ever you would like.

Now the question is, is it possible to create something like that using java, that would take all the data from the memory, that the software you're trying to "hack" in to, uses?

Let me know which sources should I look up for.

P.S. If the post got grammar mistakes, I am sorry. I am from Russia and I am not the best in English language.

possible duplicate of [Accessing memory with Java](http://stackoverflow.com/questions/19418900/accessing-memory-with-java) — alex, Apr 17 '15 at 11:21
@dit: You're right, it did not have the answer expected by OP. Deleted my comment. — LittlePanda, Apr 17 '15 at 11:25
@immibis `sun.misc.Unsafe#copyMemory` might work if you knew the location - no? — Philip Whitehouse, Apr 17 '15 at 11:31
@immibis How does a native process do it anyway - isn't the OS supposed to enforce memory protection? — Philip Whitehouse, Apr 17 '15 at 11:32
@PhilipWhitehouse [It asks](https://msdn.microsoft.com/en-nz/library/windows/desktop/ms680553%28v=vs.85%29.aspx) [the OS](https://msdn.microsoft.com/en-nz/library/windows/desktop/ms681674%28v=vs.85%29.aspx) [nicely.](http://linux.die.net/man/2/ptrace) — user253751, Apr 17 '15 at 11:33

score 4 · Accepted Answer · answered Apr 17 '15 at 11:22

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Java is very restricted in direct memory access (for a good reason), so it is very unlikely this can be done with Java. The JNI can perform (managed or unsafe) OS operations, so you could try calling any C function that returns the data at a given memory location, but I suppose you would be better off with using C in the first place (not Java), then.

answered Apr 17 '15 at 11:22

user1438038

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So perhaps I don't want to change the memory.. What if I want to read the memory? – BobTheSatan Apr 17 '15 at 11:30
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@user2852371 Then this answer still applies, no? – user253751 Apr 17 '15 at 11:32
The same applies to reading memory outside of the Java Virtual Machine. – user1438038 Apr 17 '15 at 11:39

score 1 · Answer 2 · answered Apr 17 '15 at 11:19

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By language definition java runs in a sandbox in the JVM. So it is impossible to access other places in the memory outside of it. Also Java cannot access specific positions in the memory, there are no pointers.

answered Apr 17 '15 at 11:19

andreadi

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You should probably read up on `sun.misc.Unsafe`. It can definitely access specific positions in memory. – Philip Whitehouse Apr 17 '15 at 11:28
Thank you, reading about it now. It seems that it will be part of Java 9 API. – andreadi Apr 17 '15 at 11:33

Thusitha Thilina Dayaratne · Answer 3 · 2015-04-17T11:38:17.557

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As I know you java doesn't provide support to access the memory directly. If you still wanna access the memory you have to use JNI. But then that is not a good option either. So I think best way is to give up on Java for your purpose and try to use C or C++. C#.NET would be a possible too.

P.S As @PhilipWhitehouse suggest may be there is a way with sun.misc.Unsafe package. Try to read on http://mishadoff.com/blog/java-magic-part-4-sun-dot-misc-dot-unsafe/

edited Apr 17 '15 at 11:38

answered Apr 17 '15 at 11:31

Thusitha Thilina Dayaratne

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`sun.misc.Unsafe` gives you some direct memory access. But it's unclear whether you could get to memory outside the Java process. – Philip Whitehouse Apr 17 '15 at 11:32
@PhilipWhitehouse I didn't aware of that before. I will added that to my answer. Thanks for the comment – Thusitha Thilina Dayaratne Apr 17 '15 at 11:35

Java: How do I get values from the other programs?

3 Answers3