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Handle optional parameters in QueryDSL

I am using QueryDSL with SpringData. I have Table say, Employee and I have created entity class say, EmployeeEntity I have written following service method As in above I commented the NPException. How to use QueryDSL for optional Parameters in QueryDSL using Spring Data? Thank you 🙂 Answer BooleanBuilder can …

How do I convert from YAML to JSON in Java?

I just want to convert a string that contains a yaml into another string that contains the corrseponding converted json using Java. For example supose that I have the content of this yaml in a String called yamlDoc: I want some method that can convert the yaml String into another String with the corresponding…

Add interval to a datetime

I want to achieve a similar operation in java: What’s the best approach to express this in Java given the following constraints: The datetime is a formated string. The interval is an integer. The calculated time should be also a datetime formatted string. Answer You should work with “Date” o…

How to share code between two projects?

I have two Java projects called A and B. Both of them are web apps deployed as war files. I created them in Eclipse workspace separately. Project B uses a class in project A named MusicMapper. I added the project A to project B’s build path in Eclipse as suggested in this post. So now project B can comp…

File.createTempFile check if file exists?

If I use this method, and by chance there is a temporary file with the same name, the file is overwritten? I’m talking about an application that will generate many temporary files, for a long time. Answer From the JavaDoc on createTempFile (here) on the line labeled 2, Neither this method nor any of its…

Find first element by predicate

I’ve just started playing with Java 8 lambdas and I’m trying to implement some of the things that I’m used to in functional languages. For example, most functional languages have some kind of find …

Android: Navigation Drawer vertical shadow

I have implemented a NavigationDrawer in my application. I would like to know how I can add a vertical shadow effect which is below the main Fragment, similar to the picture below. I have one image on my drawable with the shadow image. It’s called “drawer_shadow.9” but I don’t know how…

Spring MVC web application: No default constructor found

Project ZIP: http://goo.gl/ddhLg5 Spring web app cannot be executed giving HTTP Status 500 error. It also writes out that No default constructor found for DSLR but in fact there is a default constructor. Maybe it has to do with application context or the way my beans declared? What is the reason my applicatio…