Copy jar to output folder when compiling/building project in Java

Question 1

In NetBeans, switch to the "Files" tab. Expand your project (the one that is to be built).

Double click the build.xml.

There are a number of build targets that you can override...the build.xml documents them for, but here is dump

<!--

There exist several targets which are by default empty and which can be 
used for execution of your tasks. These targets are usually executed 
before and after some main targets. They are: 

  -pre-init:                 called before initialization of project properties
  -post-init:                called after initialization of project properties
  -pre-compile:              called before javac compilation
  -post-compile:             called after javac compilation
  -pre-compile-single:       called before javac compilation of single file
  -post-compile-single:      called after javac compilation of single file
  -pre-compile-test:         called before javac compilation of JUnit tests
  -post-compile-test:        called after javac compilation of JUnit tests
  -pre-compile-test-single:  called before javac compilation of single JUnit test
  -post-compile-test-single: called after javac compilation of single JUunit test
  -pre-jar:                  called before JAR building
  -post-jar:                 called after JAR building
  -post-clean:               called after cleaning build products

(Targets beginning with '-' are not intended to be called on their own.)

Example of inserting an obfuscator after compilation could look like this:

    <target name="-post-compile">
        <obfuscate>
            <fileset dir="${build.classes.dir}"/>
        </obfuscate>
    </target>

For list of available properties check the imported 
nbproject/build-impl.xml file. 


Another way to customize the build is by overriding existing main targets.
The targets of interest are: 

  -init-macrodef-javac:     defines macro for javac compilation
  -init-macrodef-junit:     defines macro for junit execution
  -init-macrodef-debug:     defines macro for class debugging
  -init-macrodef-java:      defines macro for class execution
  -do-jar:                  JAR building
  run:                      execution of project 
  -javadoc-build:           Javadoc generation
  test-report:              JUnit report generation

An example of overriding the target for project execution could look like this:

    <target name="run" depends="LED-impl.jar">
        <exec dir="bin" executable="launcher.exe">
            <arg file="${dist.jar}"/>
        </exec>
    </target>

Notice that the overridden target depends on the jar target and not only on 
the compile target as the regular run target does. Again, for a list of available 
properties which you can use, check the target you are overriding in the
nbproject/build-impl.xml file. 

-->

I would probably recommend -post-jar

If you haven't already done so, I would become farmiluar with the Ant copy task

Question 2

Use Ant build. It's better as compared to making jar using ide