This is good example of stopping thread. How to stop a java thread gracefully? But when I try to check this example I received infinite loop. This is my code: Answer I think you need to start your thread – not run it. By calling run, you are just making a normal method call, not running a separate threa…
Tag: java
How to abbreviate HTML with Java?
A user enters text as HTML in a form, for example: I want to be able to output only a part of the string ( for example the first 20 characters ) without breaking the HTML structure of the user’s input. In this case: which renders as Is there a Java library able to do this, or a simple method
How can I cascade delete a collection which is part of a JPA entity?
In one of my jobs I have the following code: This always fails to delete the entity with the following error: The DELETE statement conflicted with the REFERENCE constraint “FK966F0D9A66DB1E54”. The conflict occurred in database “TFADB”, table “dbo.MonthlyReport_categories”,…
Heap Overflow Issue when implementing and using the Printable interface
So I’ve written the class below, and it works, but we are getting some heap overflow problems when using this. The images are limited to 5 mb each. Anyone have an idea on how to solve overflowing the heap when generating the printout? } Answer Without going in the specifics of your code, maybe you reall…
Glassfish V2.1.1 Heap size never decrease after server batch job
I’ve set up a glassfish cluster with 1 DAS and 2 Node Agents. The system has TimedObjects which are batched once a day. As glassfish architecture, there is only 1 cluster instance allowed to trigger timeout event of each Timer created by TimerService. My problems is about Heap size of a cluster instance…
How to write an S3 object to a file?
What’s the fastest way to write an S3 object (of which I have the key) to a file? I’m using Java. Answer While IOUtils.copy() and IOUtils.copyLarge() are great, I would prefer the old school way of looping through the inputstream until the inputstream returns -1. Why? I used IOUtils.copy() before …
How to get frequency from fft result?
I have recorded an array[1024] of data from my mic on my Android phone, passed it through a 1D forward DFT of the real data (setting a further 1024 bits to 0). I saved the array to a text file, and repeated this 8 times. I got back 16384 results. I opened the text file in Excel and made a
Eclipse: The declared package does not match the expected package
I have a problem importing an external project. I go File -> Import… -> Existing Projects into Workspace, choose the folder where the project is located and everything is imported – but the package names of the project don’t seem to be what Eclipse expects. The package names all have a…
Could not find the main class, program will exit
I made an executable jar with the command prompt in Windows 7 using the jar cvfm MyJarName.jar manifest.txt *.class which created the .jar file. But when I attempt to open it, I get a pop-up window …
How to change MySQL timezone in a database connection using Java?
MySQL runs with timezone “GMT+8”, but Tomcat with “GMT”. When I save datetime to my database, everything seems to be OK, but when I check the datetime value in the database, I see the “GMT” value. Also when I try get the value from the database the value is changed, seems l…