I've read here that Intellj is written in java,
how then it can run without any JRE installed on the machine?
It cannot. Requirements clarifies that at least JDK 6 must be installed.
I guess some distributions might have it bundled but it is not the case for standard one version 12.
IntelliJ IDEA comes with JRE. Just look inside IDEA installation folder where you can find jre folder.
Related
I had java version 8 previous and my eclipse worked just fine. But now I have java version 7 and I can't open eclipse on my computer. What should I do? please help.
I think there are two options:
Upgrade to Java version 8 (or newer).
If you can't do that, downgrade to a version of eclipse that supports Java 7. eclipse 4.5 (Mars) (or earlier as noted on the linked page), as of eclipse 4.6 (Neon) Java 8 is required.
I feel I should note that newer versions of Java (and eclipse) can still target Java 7 (and many earlier versions).
But now I have java version 7 and I can't open eclipse on my computer. What should I do?
Use versions that work together. When you for example look at your second screen shot, it says something like "requiredJavaVersion=1.8" or so.
In other words: you can't just come in and run eclipse with any version of java.
The other answer gives you the required details.
And a final note here: in case you tried to start eclipse with that older JVM in order to "allow" to ensure that eclipse won't allow "java 8" stuff in a project: that isn't the right way then. Instead: eclipse allows you to "define" JDKs to be used for your project. So you can easily tell eclipse: "I have a Java7 jdk sitting here, please use that for project X".
You do not need to run eclipse itself with a Java7 JVM in order to use a Java7 JDK for an eclipse project!
There will be a file under the Eclipse installation directory named as eclipse.ini.
It will launch the eclipse for that specific jdf and you can change the path to your jdk7.
Hope it helps.
It depends basically on which version of the eclipse you have.
If you have eclipse 4.6(Neon) or the latest version, then you must need a newer JDK version of Java (>=1.8 which you need to download). Or If you want to roll back to an older version of Eclipse then consider downloading eclipse 4.5(Mars).
Or If you have an eclipse version of 4.5(Mars) or older then see in eclipse.ini
-Dosgi.requiredJavaVersion = 1.8 and change it to -Dosgi.requiredJavaVersion = 1.7 which can be found in the folder containing eclipse.exe file.
So I'm trying to install Eclipse IDE for Java on my main pc.
I had no problem installing it on my laptop but when trying to install it on my PC I get JRE Missing webpage.
I've installed the JDK and JRE and they are both working. I could use some advice.
i also had the problem with eclipse and the JRE.
Try to delete the 2 Java versions and deinstall eclipse.
then install the JDK first and seccond the JRE. after the 2 installations install the new eclipse version(in the installer you chan choose between some installations take the first).
i hope I can help you.
Unless explicitly told in eclipse.ini Eclipse uses the system wide java command.
Easiest for you right now is to install a system wide JRE (same 32/64 bit flavor as eclipse).
I had the same issue. It was happening when installing different match of JDK version (11 in my case), with JRE (8 in my case).
So, in order to have this installation of Eclipse working make sure that you have both JDK and JRE referring to the same version. Installation will not work if they have different versions.
After some experiences with Scratch, they told me the best option for beginners is Java, if I want to learn something usefulin future. I downloaded Java SE (JDK 10) and Netbeans and installed both. Netbeans ask for a folder that is Java, which I just installed. But it doesn't recognize the folder and says firstly no compatible version found and later the specified JDK folder does not contain JDK. What is wrong?
You have installed JDK 10 I guess. There was a contradiction in your question since you have downloaded JDK10 and installed JDK8. First of all, I would like to mention that the latest version of of Netbeans supports only JDK8.
Try installing JDK 8 and reconfigure Netbeans accordingly.
NetBeans only supports JDK 8. Install that and point to the folder for JDK 8 when NetBeans asks. If it doesn't ask again you can do it manually, shown here Changing java platform on which netbeans runs
I used to have JRE 7 before, and now I installed JDK 8 and deleted my JRE 7 folder. I'm using Eclipse Kepler, and I added JDK 1.8 to my installed JRE's. Can I delete the JRE 1.8 folder as it's taking up space in my computer? Will it cause any problems?
JRE is a part of JDK.
No need to have JRE when you have JDK. If you open JDK folder and see, you'll have JRE folder inside it which is the same of JRE folder initially you have.
As all have said that JDK includes JRE, that is perfectly right.
But let me add more on it to fulfill an industrial Structure.
While an employee works on some project, they need JDK for they need to write code as well as compile it.
But after the development process completes, the software is ready to deliver and the client's machine will have to choose whether JDK is needed or the JRE.
I would recommend to install JRE on clients' machines because clients don't have to compile the code. Clients always goes straight forward to execute it.
So, make sure to install JRE on clients' machines, not JDK. It will give the advantage of Memory - Utilization too.
Thanks.
You can delete JRE. JDK is a superset of JRE and contains everything already.
My qustion is really simple, all in the title.
After some tests I found that by given a JRE/bin directory in the path(environment variable) , Eclipse can run normally with no problem. And Eclipse will never try to find the JRE by using JAVA_HOME variable.
And in eclipse, I know that I can add installed JREs in the window preference and choose a JDK folder instead of a JRE folder. And for each project, we can change the compiler level.
Since Eclipse can also compile the codes, when is JDK used? Debug? or what?
Eclipse uses its own compiler to compile Java code. It is different than the javac compiler that comes with a JDK. In fact, you don't need a JDK to compile and run normal Java projects in Eclipse. A JRE is obviously needed to reference the required Java libraries.
However if you are using Maven or some other tools that sometimes depend on a JDK component, then you need to install a JDK on your machine. For example, Maven has an option to rely on the tools.jar that comes shipped with a JDK.
Eclipse uses the JRE you specified as default or per project settings. This could be a (only) JRE installation or a JRE from a JDK installation.
I think the more interesting question is: When should I use a JDK instead of an JRE?
The JDK includes tool that are not included in the standalone JRE. E.g. the javadoc.exe for exporting the documentation from javadoc annotated comments in the code. This Program is not included in a standalone JRE. so if you want to export your javadoc documentation you need to add an installed JRE based on a JDK installation first, so Eclipse is able to use the javadoc tool.
It could be a little hard to give a thorough answer to this but I know that at least for using Maven/m2e Eclipse needs to be run in a JDK.
First of all eclipse is a java code it wouldn't run without java installed to prove it (on your personal expence) copy the eclipse folder elsewhere and uninstal the JDK and try to run jave it wouldn't it would output the error message no JDK but instal JDK and run eclipse from the copied location it would run as a first time asking you about the workplace directory!.