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Raspberry PI 3 B+ Mango and java oracle installation


  • Hello,

    I followed your tutorial to install mango on raspberry PI.

    I’m blocked whith the command prompt :

    sudo update-alternatives --install java /usr/bin/java /usr/local/java/jdk1.8.0_221/bin/java

    as you can see with the following screenshot :

    0_1568296950585_apres_3eme_cde.jpg

    i don’t know linux , and I found on the web a syntax to declare the path for
    :/usr/local/java/jdk1.8.0_221/bin but i don’t know if it’s the good syntax.
    Here it’s what I wrote on the /etc/environment file :

    0_1568297015660_etc_environment.jpg

    Is-it correct for the path ?

    If yes , have you got any idea of my problem ?

    I can obtain JDK as you can see in the following screenshot, but not the java version :

    0_1568297062870_reponse java version.jpg

    Best regards


  • Hi JF89,

    What precisely is your question? How to run that update alternatives command?

    Setting JAVA_HOME in the /etc/environment should be sufficient to have Mango find the java executable, and is in fact preferred in the startup scripts to resolving java from the PATH.

    I would strongly advise against assigning to the PATH variable in /etc/environment as you seem to be doing.

    Have you tried to start Mango?


  • Hello Phil,

    i have many difficulties how to use linux, and i followed your tutorial step by step.
    But I encountered the problem with the path.
    In your tutorial you said :

    Add the following to the file
    JAVA_HOME=/usr/local/java/jdk1.8.0_131
    If you have path settings add at the end of PATH following :/usr/local/java/jdk1.8.0_131/bin”
    save /etc/environment (ctrl+x)

    But the syntax is not given by the tutorial.

    So that’s why I’m lookink for help.

    With your previous comment I know now that the path is not good . But i still don’t know how to write that path in etc/environment.

    I tried to start mango with sudo ./ma.sh start command in the bin directory of mango , but mango doesn’t work

    is_it because java JRE is not answering ?
    because when I check java -version , I have no answer.

    When you install JDK, does it install in the same time JRE ?

    best regards


  • here is the screnshot of the check starting mango

    0_1568320286120_mango.jpg


  • You can see in Mango/bin/ma-init.sh that it would preferentially use JAVA_HOME.

    From your error image, although i do not speak the language, I wonder if you have a /usr/bin/java and if it is executable. But, you should be able to launch Mango using only JAVA_HOME. I would add an echo into ma-init.sh to see what JAVA_HOME is when it is deciding how to find Java.


  • Hello Phil ,

    The file /usr/bin/java is present , but when i try to execute it nothings happens.

    ma-init.sh is containing already echo but i don’t know how to add one.
    As I said I don’t know how to use linux, just very few commands.

    The situation has been improved but not at all.

    I can start Mango , but it’s blocked with 5% starting

    0_1568378473645_20190913_115259.jpg

    I was unable to have the good echo when usin oracle jre 1.8.0_221

    So with the command sudo update-alternatives --config java , I choose an another version than oracle 1.8.0_221 :

    Java-8-openjdk-armhf

    ![0_1568378879190_20190913_143216.jpg](Uploading 100%)

    Now I can have a good echo for java -version

    I updated the etc/environment file with the following
    JAVA_HOME= »/usr/lib/jvm/java-8-openjdk-armhf/jre/bin/java»

    Of course there’s a problem to launch the display , because I use VNC viewer but I can see the Mango software starting when typing localhost :8080 in the webbrowser bar.

    But why Mango is blocked at 5% when starting ?

    Is-it because it’s not a oracle version of java ?

    Thanks for your help

    Best regards

    0_1568378771361_20190913_115430.jpg

    0_1568378806013_20190913_115459.jpg


  • Here is the screenshot of java versions available0_1568379059946_20190913_143216.jpg


  • The screenshot of launch output's stacktrace could be prevented by setting the env.properties entry web.openBrowserOnStartup=false

    Those screenshots prove Mango has found Java and that is not the problem, as Mango is using the JAVA_HOME variable to locate Java.


  • Hello Phil,

    It works now , connecting directly to the raspberry PI .

    But the display between custom pages or settings pages takes about 3 to 5 seconds delay, and sometimes more.

    Is-it due to the ram (only 1 gb with raspian ?)

    With a computer core I5 8th generation 3,5 Ghz , 8 GB ram , W10 , the display between pages is less than a second.

    Is it as fast for the MangoHTS ( 8GB RAM max ). (display between pages less than a second ?)
    Best regards


  • The amount of memory, other things you're doing with your browser, all could affect it. I don't know specifically where the bottlenecks are in your circumstance, nor have I collected that benchmark.