If i make java core dump with gcore then what is the best tool to analyze it? I need to be able make jmap, jstack, jstat etc and also i need to see values of all variables.
Something that can take core dump as frozen JVM.
How would one go about proving to management that a batch reformat of all .java files in a large code base (to place the code in compliance with the company's coding standards) is safe and will not affect functionality.
The answers would have to appease the non-technical and the technical alike.
What is the best procedure for storing and retrieving, using native Java serialization, generic objects like ArrayList<String>?
Edit: To clarify. When I serialize an object of type ArrayList<String> I'd like to de-serialize to the same type of object. However, I know of no way to cast back to this generic object without causing warnings.
In my code I am using java.sql.PreparedStatement.
I then execute the setString() method to populate the wildcards of the prepared statement.
Is there a way for me to retrieve (and print out) the final query before the executeQuery() method is called and the query is executed? I Just want this for debugging purposes.
Thanks.
Hello,
I'm creating a java web application runing on a Tomcat server.
One of the functions fill in a StringBuffer variable with data.
At the end, I would like to propose the user to download the generated content packaged in a text file. This without having to store the file on the server.
I've been searching for a code snippet but couldn't find anything corresponding ...
I hope I've been clear enough on my problem.
Thanks in advance,
Does anyone overload the equals method in java? The overloaded method will be
public boolean equals(final MyClass myClass)
This will have the benefit of having the relevant comparison part (guts of the method) in another method.
Details are in this blog.
Hello,
I am writing a user defined function to DB2 on AS/400 in Java and the strangest thing happen..
I am always getting the same result from the function even when i am changing it, even if i am dropping it and create it again and even when i specify NOT DETERMINISTIC..
Does any one have ever encountered a behavior like that?
Hi,
After some serious googleing I found out that the RandomAccessFile-class is not thread-safe. Now I could use one semaphore to lock all reads and writes but I don't think that performs very well. In theory it should be possible to do multiple reads and one write at a time.
How can I do this in Java? Is it possible at all?
Thanks!
Having played with Linq (to SQL and Objects) as well as the Entity Framework from Microsoft recently, I was wondering what the non-.Net (specifically Java) equivalents are?
I have a Java application complied to a collection of jars that I want to make installable on Ubuntu and SuSE. I Want the installer to be able to check for the JRE, register a file association and be able to load a website on un-install.
I understand Ubuntu and SuSE are based on different architectures, so is there a consistent way to do this?
Does anyone have an advice on utilities to use or guides to read to help me achieve what I'm trying to do.
Using JNI can we pass custom data types from Java to C (or vice versa)? I see a mapping of primitive datatypes to types in C however not too sure if we can send across our own data types (e.g. Send across or return an Employee object or something!).
Hi,
I'm not quite sure what field to use when adding more than 30 days to a Java Calendar object. Is there any difference in between Calendar.DAY_OF_MONTH and Calendar.DAY_OF_YEAR?
Example:
GregorianCalendar d = new GregorianCalendar();
d.add(Calendar.DAY_OF_YEAR, 90);
vs
GregorianCalendar d = new GregorianCalendar();
d.add(Calendar.DAY_OF_MONTH, 90);
Thanks.
hi there,
I'm looking for an solution to generate a checksum for any type of java object, which remains the same for every exection of an application which produces the same object.
I tried it with object.hashcode(), but as I read in the api
....This integer need not remain consistent from one execution of an application to another execution of the same application.
thank you, best regard alex
I am actually new to java programming and am finding it difficult to take integer input and storing it in variables...i would like it if someone could tell me how to do it or provide with an example like adding two numbers given by the user..
Is there a way in Java to find the "Last Fired Time" from a Cron Expression.
E.g. If now = 25-Apr-2010 10pm, cron expression "0 15 10 ? * *" (quartz) should return me 25-Apr-2010 10:15am
I do not care if we use standard cron expressions (like Unix and Quartz) or less popular ones if they can fetch me the correct "Last Fired Time"
I have to burn a java-application on a cd. This application have to run on every windows pc wihtout any installation (also jre shouldn't be installed) before.
Hi,
I'm a beginner in java. I want the logic of the small program.
I have two arrays
array = {a1,a2,a3,a4,a5,,,,,,,,,an}
and
array2 = {b1,b2,b3,b4,,,,,,,,,,,bn}
I want string as:
a1b1,a2a3b2b3,a4a5a6b4b5b6,..........an
Please tell me what will be the logic.
More of a wiki list/collection, I'm looking for a list of good Java desktop apps. I've added a couple below to get started. Please list the framework/widget toolkit being used if it's know as well.
I'm using a MySQL database and accessing it through Java.
PreparedStatement prep1 = this.connection.prepareStatement("UPDATE user_table
SET Level = 'Super'
WHERE Username = ?");
prep1.setString(1, username);
The update statement above works fine however I'd like to get the number of rows affected with this statement. Is this possible please?
Basically I want to be able to encrypt and decrypt with AES 256. What is the industry standard library for encryption in Java? Something that has been around a long time and is tried and true.
I know in Jython you can do
import java.util.Random as Random
Random().nextInt()
But if I have a class I wrote myself, how can I import it into Jython without putting the class itself in a package? If I have a testclass Test:
public class Test {
public void foo() {
System.out.println("bar");
}
}
that's not inside a package. Can I even import that into jython by using something along the lines offrom Test import Test?
I have been working with the Swing library for a long time, I'm working on a new project for school and due to the nature of the program it can't look like a generic/boring swing gui. So my question is does anyone know of an interesting java gui library that is not swing or awt?
I need to use a few Cyrillic characters in a Java file and in order for Eclipse to allow me to do so I need to change the encoding for that file (currently to UTF-8).
Are there any possible problems that this could cause?