CODEWITHSUNDEEP
javaeclipsemaven
alicjasalamon
alicjasalamon

Reputation: 4291

Why can I run my program after cleaning in Eclipse and Maven?

I cannot understand why in Eclipse after these two steps

  1. Run as -> Maven clean
  2. Project -> clean...

I can still run my program using green icon with white arrow?

I thought there are no .class files after cleaning. I was expecting exception like ClassNotFound, but nothing like this happened.

Do you know how to properly clean project in Eclipse?

Upvotes: 2

Views: 1104

Answers (4)

herrtim
herrtim

Reputation: 2755

I just checked this phenomenon out with one of my Maven projects in Eclipse and this is what I observed. By the way, don't trust what you see in the Package View, use your file system explorer.

Run as -> Maven clean : deletes the target folder Project -> clean... : creates target folder with empty subfolders "classes" and "test-classes". In Eclipse's Package Explorer view, I see an empty target folder.

At this point I would say the proper way to clean a Maven project in Eclipse is simply to do Run as -> Maven clean.

Now to address why your program runs after cleaning. As soon as I ran a program in the project, Eclipse compiled and populated the "target/classes" and "target/test-classes" folders with *.class files and resources. In Eclipse's Package Explorer view, I still see an empty target folder.

The trick to figuring this out was to look at the project directory and sub directories with the system file explorer and not just with Eclipse's Package View or Project View.

Upvotes: 1

kodstark
kodstark

Reputation: 490

In starting code for your application you can add: 

System.out.println("Classpath=" + System.getProperty("java.class.path"));

you can analyze it (nornally I use notepaddpp to split it by classpath separator and sort) - maybe it refers to jars in maven repo which contains classes as well? Sometime class folders are first on classpath and thus are before jars even if in jars there are the same classes.

Upvotes: 1

AlexR
AlexR

Reputation: 115328

Clean in eclipse is not the same as clean in maven. Maven's clean indeed removes all compiled resources (classes etc). Clean project in eclipse is a kind of mvn clean compile, i.e. it removes *class files and compiles all *.java files again.

Upvotes: 3

Minion91
Minion91

Reputation: 1929

This is probably because eclipse will auto build your project when you run it

Upvotes: 0

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