ArrayList<> cannot be resolved to a type
You probably need to add an import statement. This goes after your package declaration. This let’s the system know what an ArrayList is and what methods it has available. Hope that was it!
java
How to check if object is null or not except == null
The easiest way to check is entity == null. There is no shorter way to do that. Note that there is a method for this in the standard lib: Objects.isNull(Object obj) And another one which is the opposite of the above one: Objects.nonNull(Object obj) And there is yet another one which can be used to force … Read more
hibernate properties not found
I guess the problem is with the code for configuration you mentioned for .hbm.xml may not be working in Tomcat. I think it needs AnnotationConfiguration object. I guess you used this code due to the Annotationconfiguration object creation is not working. Better create a maven hibernate project with pom and export the war file to Tomcat (with the changes of Annotationconfiguration). Also use log4j … Read more
Java: Unresolved compilation problem
(rewritten 2015-07-28) The default behavior of Eclipse when compiling code with errors in it, is to generate byte code throwing the exception you see, allowing the program to be run. This is possible as Eclipse uses its own built-in compiler, instead of javac from the JDK which Apache Maven uses, and which fails the compilation completely for … Read more
HTTP Status 500 Error instantiating servlet class
I think somethin wrong in this section: Instead try:
Error: Main method not found in class Calculate, please define the main method as: public static void main(String[] args) [duplicate]
Restart your IDE and everything will be fine
The specified child already has a parent. You must call removeView() on the child’s parent first (Android)
The error message says what You should do.
Exception in thread “main” java.lang.StringIndexOutOfBoundsException: String index out of range: 0
nextDouble() leaves the newline in the input stream, so when you then call the result of nextLine() is an empty string. Remove the newline from the stream, or use next(), as you did above.
Error: Generic Array Creation
You can’t create arrays with a generic component type. Create an array of an explicit type, like Object[], instead. You can then cast this to PCB[] if you want, but I don’t recommend it in most cases. If you want type safety, use a collection like java.util.List<PCB> instead of an array. By the way, if list is already a java.util.List, you should use … Read more
Initializing multiple variables to the same value in Java
This should work with immutable objects. It doesn’t make any sense for mutable objects for example: All the variables would be pointing to the same instance. Probably what you would need in that case is: Or better yet use an array or a Collection.