I’m just writing a small program that receives input from the user then prints it back to them. However, when I run the program it asks for input twice (it prints the initial statement, then once you type and press enter, nothing happens, but if you do it again it works and prints.) The top value appare…
Tag: java
How to sort an array of objects in Java?
My array does not contain any string. But its contains object references. Every object reference returns name, id, author and publisher by toString method. Now I need to sort that array of objects by the name. I know how to sort, but I do not know how to extract the name from the objects and sort them. Answer…
Invalid operation for read only resultset: updateString
Following is my code(Re-constructed) which select & update STATUS field depending upon the conditions. (Using Servlets, Oracle as Backend and JDBC driver) I am getting the error while updating: Any suggestions will be appreciated. Update 1: The same code was working when select statement was selecting dat…
Tomcat 7.0.43 “INFO: Error parsing HTTP request header”
I use Tomcat 7.0.43 with a websocket application. My app works fine in Tomcat 7.0.42 but with 43 I get the following output when I try to access my server on websockets: My browser console shows the following: Here is the access log for that request: What has changed in Tomcat 7.0.43? What do I have to change…
What is the difference between CascadeType.REMOVE and orphanRemoval in JPA?
What’s the difference between and This example is from Java EE Tutorial, but I still don’t understand details. Answer From here:- Cascading Remove Marking a reference field with CascadeType.REMOVE (or CascadeType.ALL, which includes REMOVE) indicates that remove operations should be cascaded autom…
Dragging an undecorated Stage in JavaFX
I would like to have a Stage set to “UNDECORATED” made draggable and minimizable. The problem is that I can’t find a way to do so since the examples I come accross that do this do so via methods inserted inside the main method. I would like to have this done via a method declared in the cont…
Is it a known good practice to use a big try-catch per method in java? [closed]
Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 9 years ago. Improve this question I’ve been interviewed recently and the interviewer wanted me to…
Java Virtual Machine Heap Tuning Parameters
What would be the effect of setting only -Xms without setting a -Xmx for eg. java -Xms 2048m ? Does setting a high lower value for -Xms mean lesser Heap Fragmentation? Answer Setting -Xms to the estimated heap requirement of your application will speed up start of your application (of course Xms must be <=…
How to assert greater than using JUnit Assert?
I have these values coming from a test and I try I get the java.lang.AssertionError and detailMessage on debugging is null. How can I assert greater than conditions in using JUnit Answer Just how you’ve done it. assertTrue(boolean) also has an overload assertTrue(String, boolean) where the String is the…
Return Java system exit value to bash script
I am trying to get the return value from a java program ( System.exit(1);) into a shell script, but it seems like its returning the jvm exit code, which is always 0, if it doesnt crash. For testing purposes, this is the very first line in my main(). Anyone know how to do this? My bash code: Thanks Answer If