I need to bring from DB only one single result. How can I do that with JPA? I tried “select t from table t” but didn’t work. Any other ideas? Answer Try like this It should work UPDATE* You can also try like this
Tag: java
Eclipse – passing VM parameter to every test in the project
I need to pass a VM parameter to every test that is run in the project. Setting this manually doesn’t seem to be the most convenient solution, so is there any possibility to pass the parameter to every test automatically. Thank you for help. Answer We change the JRE Configuration in Eclipse (Preferences…
XML to Java Object
I am trying to convert an XML file to a Java Object, now, I have read of JAXB, XStream, Sax and DOM, I’d like to convert this sort of type of xml: it might be as well as: I wanted to know if there is anything out there (and possibly not 3rd party) that I can use, without declaring a
Minecraft javascript error
I am trying to make a script that draws a circle for minecraft using singleplayer commands. For starting, I tried to do the basics; here is my code: But when I run it, it says: Failed to execute: The choice of Java constructor setY matching JavaScript argument types (string) is ambiguous; candidate constructo…
First occurrence in a binary search
I’m tinkering with some code and I realized something I never knew. A normal binary search will return a random index in a data set for a key that occurs more than once. How can I modify this code below to return the first occurrence? Is this something people do? Answer Having found a matching value, yo…
Strip Leading and Trailing Spaces From Java String
Is there a convenience method to strip any leading or trailing spaces from a Java String? Something like: Result: myString.replace(” “,””) would replace the space between keep and this. Answer You can try the trim() method. Take a look at javadocs
How would I create a JFreeChart scatterplot best fit line
I have an arraylist of points I want to include in a JFreeChart scatterplot. That works fine, but I now want a best fit line on it. After some searching, JFreeChart doesn’t support such calculations directly, so what I want to do is calculate it myself and then stick a line into the chart manually. How …
SocketChannel: Single or multi , which is better?
SocketChannel is thread safe, so only one channel is need for communication between client and server. the channel served for read/write operations simultaneously But, if we using multi channels (more than one connections between the same client and server), will the io performance be improved ??? If can, why…
Capturing speaker output in Java
Using Java is it possible to capture the speaker output? This output is not being generated by my program but rather by other running applications. Can this be done with Java or will I need to resort to C/C++? Answer I had a Java based app. that used Java Sound to tap into the sound flowing through the system…
Creating a string attribute in Weka Java API
I’m trying to create a new string Attribute using Weka’s Java API… Reading through the API javadocs, it appears that the way to do so is to use this constructor: but I’m stuck as to what I should pass into the attributeValues parameter… when I put in null, Java complains about pr…