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Unexplainable differences between Java on OSX and Blade VPS

I'm developing a Tomcat Web Application. I'm using apache-tomcat-9.0.10 on both my development machine (Mac OS High Sierra) and my Blade VPS (Debian 8.1). Both give the following output on java -version:
Local:
java version "10.0.1" 2018-04-17 Java(TM) SE Runtime Environment 18.3
(build 10.0.1+10) Java HotSpot(TM) 64-Bit Server VM 18.3 (build
10.0.1+10, mixed mode) Evert-Jans-MacBook-Pro:apache-tomcat-9.0.10
Remote:
java version "10.0.1" 2018-04-17 Java(TM) SE Runtime Environment 18.3
(build 10.0.1+10) Java HotSpot(TM) 64-Bit Server VM 18.3 (build
10.0.1+10, mixed mode)
The Java settings are equal on both my Local machine and the remote VPS.
Yet, Locally it works but the remote server gives a 'page can’t be found error'.
Any ideas? Please let me know.

I solved the issue. I didn't upload the Lucene index which the app expected under/usr/local/index/.
Apache Tomcat could have given a more descriptive error than 404, which caused me to go and seek in the wrong direction.

topcoder java client blocked by java security

I'm using javaws ContestAppletProd.jnlp to run the latest topcoder client on ubuntu 16.04.
java version is
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode).
I've added http://www.topcoder.com to the exception site list in java security control panel, but it doesn't work.
This is the trace log file.

Java Performance on Macbook Pro (not GUI)

I have some Java code to fetch data from SQLite and do some linguistic processing (lemmatization) with the data and write the modified data into another SQLite datebase. The database tables have indexes, so the query should be fast although the data is joined.
The small program shall produce a database being used in an iPhone app.
On my Ubuntu PC (14.04.3 LTS) this program runs fast, but on my Macbook Pro (OS X El Capitan 10.11) it runs 10 or more times slower.
java -version on Ubuntu PC:
java version "1.7.0_80"
Java(TM) SE Runtime Environment (build 1.7.0_80-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)
java -version on Macbook:
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)
I also pointed eclipse to jdk 7 in Java->Installed JREs to have the same version as on the Ubuntu PC
The java command generated by eclipse is the same on both machines:
/path/to/jdk7/java -Dfile.encoding=UTF-8 -classpath
... many jars ...
my.package.myclass
How to get the same speed on the Macbook? Is the java implementation just not that fast under Mac OS?

Java URL("file://") doesn't work on Windows XP

For some reason the following code doesn't work on Windows XP.
new URL("file://" + tempfile.getAbsolutePath());
I'm using Java 1.6.
Java(TM) SE Runtime Environment (build 1.6.0_31-b05)
Java HotSpot(TM) Client VM (build 20.6-b01, mixed mode, sharing)
However, the same code just works fine in OS X (Lion) and Java 1.6
java version "1.6.0_29"
Java(TM) SE Runtime Environment (build 1.6.0_29-b11-402-11M3527)
Java HotSpot(TM) 64-Bit Server VM (build 20.4-b02-402, mixed mode)
Linux (Linux 2.6.32-38-generic #83-Ubuntu x86_64 GNU/Linux) with Java 1.6
java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode)
Based on this the above code should work.

On the localhost the URL looks like:
file:///Folder
Very important the third slash...
On Windows the Folder looks like:
file:///C:/path/

What is the problem with File.toURI().toURL()? Why reinvent the wheel?

The following code should avoid all the hassles
new File(tempfile.getAbsolutePath()).toURI().toURL()

Setting HotSpot(TM) Server VM in Java 1.6 environment

I have a question related to setting Java hotspot server VM in java 1.6
is there any way to set Java HotSpot Server VM in java 1.6 environment? When i run following command
java -version
it's showing as below,
java version "1.6.0_16"
Java(TM) SE Runtime Environment (build 1.6.0_16-b01)
Java HotSpot(TM) Client VM (build 14.2-b01, mixed mode, sharing)
I want this has to be displayed as below in third line.
Java HotSpot(TM) Server VM (build 14.2-b01, mixed mode, sharing)
Is there any command so that whenever we run java -version, it will always show Hotspot Server VM rather Client VM??
Thanks
Robert.

Add the -server flag:
java -version -server
outputs
java version "1.6.0_21"
Java(TM) SE Runtime Environment (build 1.6.0_21-b06)
Java HotSpot(TM) Server VM (build 17.0-b16, mixed mode)

You should try 'java -server -version' instead. You will need to have the server hotspot compiler installed or use that on the JRE that comes bundled with the JDK (which comes with server hotstpot).

I seem to remember reading somewhere that the JVM will start in server mode automatically if the system meets certain specifications in terms of number of processes and amount of memory. Can't remember the details or find the info though.
Edit: Found some info here
http://download.oracle.com/javase/6/docs/technotes/guides/vm/server-class.html
Server class machine is > 2Gb RAM and > 2 processors.

Simply add the '-server' flag !