Solving "JPA Project Change Event Handler (waiting)" annoying message from Eclipse

I'm using Eclipse Oxygen IDE and I'm always getting this annoying message "JPA Project Change Event Handler (waiting)" after saving a file, but I'm not using JPA in my project.

I tried to turn off the JPA validators under Preferences, with no success and the message kept appearing. Now I've found out that the guilty for the message appearing is the Dali/JPT plugin.
Since I do not need this plugin, I uninstalled it from the "Preferences" > "Install/Update"> then click again in the "Uninstall or update" link under that tab and finally I've selected, from the "Installed Software", the "Dali Java Persistence Tools - JPA Support" entry. Then I uninstallled it.

Problem solved!

ObjectAid UML Explorer for Eclipse

ObjectAid UML Explored for Eclipse is an Eclipse plugin to show the Java source code and libraries in live UML class and sequence diagrams, that automatically update as your code changes.

ObjectAid UML Explorer, class diagram.

Using Eclipse to generate hashCode() and equals()

Right-click at the selected file, choose Source-> generate hashCode() and equals()
Then you can choose which attributes uniquely identify the object and then Eclipse generates hashCode() and equals() implementation like this:

/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((code == null) ? 0 : code.hashCode());
return result;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (!(obj instanceof OtherObject))
return false;
OtherObject other = (OtherObject) obj;
if (code == null) {
if (other.code != null)
return false;
} else if (!code.equals(other.code))
return false;
return true;
}


Eclipse - Failed to load the JNI shared library

Eclipse started to fail during the opening of it, showing a pop-up window saying "Failed to load the JNI shared library". I did not know what was this and started to look on the web.

Eclipse "Failed to Load the JNI shared library"

I've found out that this was a compatibility issue with jre/jdk 32 bit on a 64 bit machine.
I was running Eclipse 64 bit, with Windows 7 64 bit...
I remembered that I had installed a new software recently... and that installation added a jre 32 bit in the begining of my path. Due to this, Eclipse 64bit was being launched with a 32bit jre, causing that pop-up to appear.
Removed the jre 32 bit from the path, and then I was able to launch Eclipse again, like before!

Problem solved.