jvm « Development « Java I/O Q&A





1. FileNotFoundException thrown when the file does exists    stackoverflow.com

I'm facing this strange problem. I'm trying to read a file that is located in another machine as a shared resource:

\\remote-machine\dir\MyFileHere.txt
When I run a standalone application ( a 16 lines java file ...

2. Is the Java Virtual Machine really a virtual machine in the same sense as my VMWare or Parallels file?    stackoverflow.com

Is the Java Virtual Machine really a virtual machine in the same sense as my VMWare or Parallels file?

3. What is the purpose of jvm.cfg file in relation to Java?    stackoverflow.com

It has some strange keywords. Please explain the general purpose of the file.

4. Interpreting the contents of the hs_err_pid file    stackoverflow.com

Below is a part of the hs_err_pid

Heap
 PSYoungGen      total 13888K, used 9807K [0x8a330000, 0x8b140000, 0x914f0000)
  eden space 13504K, 69% used [0x8a330000,0x8ac67710,0x8b060000)
  from space 384K, ...

5. Making sure file gets deleted on JVM exit    stackoverflow.com

Does File.deleteOnExit() guarantee that the file is deleted even if the JVM is killed prematurely?

6. Retrieve main class/jar file name passed to the JVM    stackoverflow.com

As a C++ app, is there a way to query a java process(java.exe/javaw.exe) to retrieve the main class or jar file name that was passed to the JVM? I want the same ...

7. How JVM access the file system    stackoverflow.com

I have an argument with my boss who is convinced that the JVM uses JNI to access native things like the file system. I think he is wrong because the JVM ...

8. Is there an equivalent to BCEL (Java .class manipulation) but in C or C++    stackoverflow.com

Is there a C or C++ compatible library for reading and writing Java class files? I.e. something like Apache BCEL.

9. Considerate migration plan for Java5/Java6 applications to Java 7?    stackoverflow.com

I'm currently investigating if it makes sense to delay some minor planned refactoring work and combine it with the migration to Java 7, but I'm a little bit concerned that it ...





10. what is shared objects file?    stackoverflow.com

When run the jvm in verbose mode it shows files are loading from shared object file as shown below

[Loaded java.lang.Object from shared objects file]
[Loaded java.io.Serializable from shared objects file]
[Loaded java.lang.Comparable from ...

11. What is maximum file size that can be handled by the JVM?    stackoverflow.com

I wanted to know the maximum file size that can be read by Java code? I wanted to handle file size of 100mb. is this possible? If possible what are the JVM ...

12. Merging JVM and the code into a single file    stackoverflow.com

I would like to merge Java Virtual Machine and my .java code (or compiled .class files) into a single executable binary. How can I do this?

13. Java Crashed application - how to read crash file generated by JVM?    stackoverflow.com

I have java aplication and it started to crash sudently, without no exception. But sometimes JVM creates crash log file, which has name like: "hs_err_pid10930.log". Can anybody read it and tell ...

14. Passing an entire file to JVM arguments    stackoverflow.com

I have several systems that all need to load the same properties to the JVM. I can use the -D flag to load one property at a time, but i ...

15. why would an hprof file have a much smaller size than the amount of memory given to the jvm    stackoverflow.com

Our code runs with -XX:+HeapDumpOnOutOfMemoryError flag so we get an hprof file on OOM. Recently I got such a file from an installation, I opened it with Eclipse memory analyzer (MAT) ...

16. Using java file locks within single JVM and across multiple JVMs    stackoverflow.com

I guess I miss something, but I cannot understand how file locks work in Java. To be more exact - how it is implemented. It seems I cannot acquire (even cannot attempt ...





17. Crash-resistant Java IPC    stackoverflow.com

I have a Java program which depends on a native library that crashes randomly (and therefore bring down the whole JVM). This library is about I/O, therefore can be easily isolated from ...

18. Does creating a File object create a physical file or touch anything outside the JVM?    stackoverflow.com

Java class File has 4 constructors:

  • File(File parent, String child)
    Creates a new File instance from a parent abstract pathname and a child pathname string.
  • File(String pathname)
    ...

19. Access bundled Java file from outside the JVM    stackoverflow.com

Is it possible to access a bundled Java file from outside the JVM? My particular issue is that I have Ruby scripts bundled with my application that I need to ...

20. Is there a jvm argument that causes the jvm to create an hprof file when the jvm starts up    stackoverflow.com

One of our testers keeps getting a small hprof file created on his windows environment when he starts our application.

  • The hprof file is only showing up on his windows instance. Other ...

21. HeapDumpOnOutOfMemoryError creates empty hprof file    stackoverflow.com

Sometimes, quite seldom, I encounter strange behavior - hprof file that is generated when OutOfMemoryError is thrown has zero length. I can think only about disk problem, but this is not the ...

22. JVM crashes without any core file generated    stackoverflow.com

Usually when ever my jvm crashes it generate the core file, but for one incident it doesn't generated the core file, didn't got any clue ? Why the Jvm crash the core ...

23. JVM    coderanch.com

24. Change default character set of JVM    coderanch.com

25. Files locked by JVM(?) on NTFS    coderanch.com

Hello All! The environment: Java 1.5, Windows Server 2003 / Windows XP (both using NTFS) java.io.File The situation I process a lot of files of various sizes located in a folder. The processing involves reading only, no writing. When the processing is finished, I wish to move the files to other folders, depending on the outcome of the processing. Some files ...

27. what is jvm.cfg file and its use?    coderanch.com

28. A question about copy of a File/jar which is running in jvm.    coderanch.com

I get a old jar-file running in a jvm and a new jar-file in another folder.I think the old is locked by the jvm. but i can use copy cmd to copy the new file and overwrite this old file.(copy cmd/ctrl+c,ctrl+v). but i can not use cut/paste to finish it(move cmd/ctrl+x,ctrl+v). it will get a error window. if i stop the ...

29. Need to persist data in JVM....    coderanch.com

Hi, I have a requirement in my project where once the user logs in, the database is queried and some information related to the user is retrieved and stored in JVM.So the number of hits to the database is decreased. The requirement in detail : This is Simple Cart-Shopping application. There is a UI which displays various products which one can ...

30. Does any file represent jvm ?    coderanch.com

Hi All, After installing jdk,i can see jre in C:\jdk150_11. tried to look jvm.I did search and got below files. jdk150_11\jre\bin\client\ jvm.dll jdk150_11\jre\bin\server\ jvm.dll jdk150_11\jre\lib\ jvm.hprof.txt jdk150_11\jre\lib\i386\jvm.cfg jdk150_11\lib\jvm.lib jdk150_11\demo\jvmti\hprof\src\jvm.hprof.txt 1.In the above files,which one represents jvm ?. 2. I got from net JRE contains JVM.But jdk150_11\lib folder also contains jvm.lib.Then can we say other than JRE ,JDK also contains JVM ?. ...

31. Read from file without loading into the JVM?    coderanch.com

Is it possible to read/write (using a stream maybe?) from a file without actually loading the whole thing into the JVM? I am used to loading the whole file into memory but I realize if a file becomes to large it will hog resources. Is there any way I can maintain low memory usage and the ability to constantly read/write data? ...

32. Instance of JVM and Serialization    coderanch.com

Hi all, I am confused about the term "instance of jvm" referring to this statement in K&B. "Clearly in Java it wouldn't make any sense to save the actual value of a reference variable, because the value of a Java reference has meaning only within the context of a single instance of a JVM." Please make this statement clear.What does instance ...

33. how jvm understand that from which point print in newline while coping from file a to b ?    coderanch.com

mine mam told me that with this line buffoutput.newLine(); we can tell jvm to print on next line , but i think there is something wrong with jvm ..lolz ..jokes apart but tell me whats wrong in this code my file "a" contents are hi what you do in spare time ? hi what you do in spare time ? in ...

34. Error: could not open `C:\Program Files\Java\jre6\lib\i386\jvm.cfg'    java-forums.org

Hi i'm in a greate problem with my myeclipse on opening it will show the jpeg(erro.jpg) i attached or afer several time while refreshing the project. The main problem i think that project is mainly forwarding by my tl after inserting the necesessary changes in code as well as the jsps ,he is using jdk 1.5_11 and in my system i ...

35. Need help to change default directory. Any Java virtual machine parameter?    forums.oracle.com

what happens is that I use a program made in java, with has a similar window. Every time i open it, I'm prompted to save my files in a default directory. What I would like to do is somehow change this default directory. I thought JRE could have some option for this!! Thanks again

37. saving files and future Java Virtual Machine updates questions    forums.oracle.com

So I've made A program that keeps a list of Ingredients and Recipes for my dads small business. This program is currently on 3 computers my dads, the secretaries, and mine. I made it so it saved and loaded from a shared folder in the network where all the computers has access. The secretary and my dads computer saved and loaded ...

38. File not showing changes inside JVM    forums.oracle.com

Hi all, I wrote a Java app that lists jpeg files as thumbnails and allows modifications such as rotation, cropping... When I save the changes (let's say a 90 degrees clockwise rotation) I made to one file inside my app and reload the same file in my app's list the changes (i.e. the rotation) are all gone away. The file is ...

39. CharSequence backed by File, auto-delete when JVM exits. Possible?    forums.oracle.com

Hi, I wanted to write a static method that from any CharSequence constructs a new CharSequence for which the character data is held in a File rather than in memory (I am writing an application that deals with rather huge strings, only portions of which are of interest at a time). So I did: File file = File.createTempFile("temp", ".dat"); [write the ...

40. Problem Closing Files - JVM Freezes    forums.oracle.com

Very strange behaviour since if you click the close button it generates an END_EVENT and this bit of code calls: System.exit(0); This should kill the program ! put some more System.out.println into your code and confirm that when you press Close you do get an end event in the case where you have not pressed the stop button. Are you sure ...