Sonar or FindBugs Critical issue: Performance - Method concatenates strings using + in a loop

This issue arises when there is a String being built in a concatenation loop.
For each iteration, the String is converted to a StringBuffer/StringBuilder, appended to, and converted back to a String. This can lead to a cost quadratic in the number of iterations, as the growing string is recopied in each iteration.

Better performance can be obtained by using a StringBuffer (or StringBuilder in Java 1.5) explicitly.

For example:


// This is bad
String s = "";
for (int i = 0; i < field.length; ++i) {
   s = s + field[i];
}

// This is better - StringBuffer is synchronized
StringBuffer buf = new StringBuffer();
for (int i = 0; i < field.length; ++i) {
   buf.append(field[i]);
}
String s = buf.toString();



//Even better - better performance if synchronization is not an issue
StringBuilder builder = new StringBuilder();

for (int i = 0; i < field.length; ++i) {
   builder.append(field[i]);
}
String s = builder.toString(); 




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.