This question already has answers here:
How to check if a folder exists?
(10 answers)
Closed 7 years ago.
Does anyone know what happened to the path.exists() API method in the latest Java 7 API?
I cannot find the change in the change logs, and between b123 and b130, the method has been removed from the API.I see that there is a static Files.exists method but I'm not sure if that is the replacement or not.
Is anyone following the Java 7 work close enough to know how this should be handled?
Thanks for any help.
Files.exists
Look in the Files class for the static methods exists() and notExists(). Both take a Path.
I guess they decided it made more sense as a static rather than instance method.
Related
This question already has answers here:
Where can I find the Java JDK source code? [closed]
(11 answers)
Closed 6 years ago.
In java, is there any way to access the methods to classes that already you import? For example, is there a way to view the code for all the methods used for arrays? Such as the constructors, add(), remove(), size()? I have checked oracle, but there is no code, only method names and parameters. I understand how the methods work, but i'd like to see the actual code used.
Search for the JDK source code, depending on the version you want.
This question already has answers here:
What is a serialVersionUID and why should I use it?
(25 answers)
Closed 7 years ago.
I was following the article http://javapapers.com/core-java/serialversionuid-in-java-serialization/ to understand Seriliazation.
In this its said that Java serializationUID recommended to be unique. I dont understand the reason for that.
Can someone please explain?
In this its said that Java serializationUID recommended to be unique. I dont understand the reason ...
It's wrong. There is no reason not to use 1L for every class, except in the case where you are retrofitting to a class that was initally defined without one, in which case you have to use what the serialver tool tells you.
As a matter of fact you can't use a unique value for every class, because it's a hashcode.
Don't rely on arbitrary Internet junk like this. Use the Javadoc and the specifications.
This question already has answers here:
Crossed out imported java packages
(2 answers)
Closed 8 years ago.
I tried to call the method .getHours() and Eclipse marks the name of a function with a line.
Why is this happening?
The method is deprecated, e.g., annotated with #Deprecated.
It means you probably shouldn't be using it, since support may disappear in the future.
That mark means that the method has been deprecated. This means the author of the code intends you to avoid that method, but doesn't remove it because of compatibility.
If you check the javadoc is possible the author has left documented an alternative way to perform the behavior.
This question already has answers here:
Why is using a wild card with a Java import statement bad?
(18 answers)
Closed 9 years ago.
I am a student, and a couple of the books I have been reading (Java for Dummies, for one) has said using the wildcard import statement is bad programming practice and encourage the reader to avoid using it. Whereas, in class, we are encouraged to use it. Can somebody please explain why it is poor programming practice?
If so, what adverse affects does it have on the program performance? For example, slow it down.
The more you insert, the higher the change that you will get a naming collision where two classes have the same class name:
http://en.wikipedia.org/wiki/Name_collision
The first example i can find within the java API are:
http://docs.oracle.com/javase/6/docs/api/javax/naming/Binding.html
http://docs.oracle.com/javase/6/docs/api/org/omg/CosNaming/Binding.html
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Get current stack trace in Java
Here is the thing, i want to get a list of all called methods in a java class. So far i've been using eclemma, but that just insn't enough. I also want the order in which the methods have been called.
You can log each method as it is called (with its arguments if you like). You can add a line to each method or use AOP to do this for you.