May be its a newbie question...
I want to use latest eclipse available. It requires Java 8. However, our company uses java 6 for all projects.
So:
Should I download eclipse that is compatible with Java 6 only ?
or I can configure Java 6 for all the projects regardless what eclipse uses?
Would there be any issues, if its possible to use two versions (one for eclipse and another one for project)?
I know its a newbie questions. But the search did not yield a proper response.
no, you can use the latest Java for Eclipse. The JDK used for project can be configured per project or per workspace. You can install as much JDKs as you desire. i.e. You can start Eclipse using a 32Bit JDK while using a 64Bit JDK for Java EE-Servers or Projects, it has basically nothing to do with the JRE used for Eclipse. You just need to set it up.
Related
So I am trying to learn how to code minecraft mods for 1.8.9. This is an old version and I was told to use Java 8 to code it. I tried to run Java 8 with Eclipse but from what I am seeing, it only uses version 11+.
Is there a way to maybe download an old version of eclipse that will run 1.8.9 gradle?
The current Eclipse can run code using any version of Java. Eclipse itself needs at least Java 11 to run, many Eclipse downloads include a suitable Java.
Once you have installed Eclipse you can tell it about other versions of Java which can be used to run programs. Open the Preferences and on the "Java > Installed JREs" page add the JRE/JDK you want to use. You can specify as many versions as you like here.
You can then choose the Java to use in the project Properties and in the Run Configuration.
I am a regular IntelliJ user, but most of my co-workers use Eclipse. A lot of them say the latest version of Eclipse "2020-09", which requires a JRE "higher than Java 8" in order to run, cannot be used to develop projects requiring JRE8.
This is pretty surprising to me, since I know it is possible to install multiple JDKs and JREs on one machine, I've done it plenty of times.
What is the typical way a person would configure Eclipse 2020-09 (already installed) to work on a project that requires a Java 8 JRE?
JRE 8 apps in eclipse workspace is possible by having the jre 8 jdk. It is true that in order to use eclipse 2020-09 you need java 11+ jdk/jre, but making projects that support jre 8 is still possible.Even I still use 2020-06 and before. Here is a method you could use to get JRE 8 implemented back in your project. Although you can change the defaults, this one will help you change the environment back to java 8 for 1 project.
Right click the library named somthing like "JRE system library[JavaSE-11]". Press properties. This is what you will see JRE System Library chooser image
Choose "Alternate JRE" then click "Installed JREs"Step Image
Press "Add" then you will see 3 options. Choose standard VM. Find your java 8 jdk directory. Usually it is something like C:\Program Files\Java\jdk1.8.0_251.
You can configure the default arguments for your jvm runtime. Then simply hit ok,select the jdk-8 library and close it. Then choose alternate jre again and in the drop-down choose jdk-1.8.0 or some name like that. This will only work if you also have java 8 installed alongside java 11 that is configured properly JDK
You can use Java 11 to start the Eclipse 2020-09 and configure a project to compile with Java 8. The problem is if you want a Eclipse plugin that uses CORBA for example. This module was removed from Java 11 earlier. In this case, I recommend to use Eclipse 2020-06.
Earlier versions of 2020-09 was working with Java 8. I had it, too. Then I updated and I got the same error message like you.
I propose to use an older one or to install JRE 11 and set the JAVA_HOME env variable to it.
The inside the IDE you can set java 8 like an JDK and develope your project with Java 8 while eclipse is running with 11.
I have a Java project in eclipse 4.5.2 that is compiled using the Java 1.7 JDK. I want to change part of this project (one package nested roughly 6 levels deep) to compile using the Java JDK 1.8. Is this possible?
I wish to do this because the branch of the product this project represents has already been released, but we want to update part of our testing code so we can use a more recent version of Selenium.
You can not use different Java Versions in one Project. the only way is to make different Project.
You cannot do that through eclipse. Because Eclipse has option to select JDK by default or you can use it project wise only.
Since Java has full backward compatability, therefore you can use newer version on whole project without any problem.
How can I change the Projects Runtime Platform?
(standard NetBeans [8.1] Java Project [Java Application])
Details:
using Ubuntu with NetBeans 8.1
I have installed JDK 1.6, JDK 1.7 + JDK 1.8
My projects platform is Java 6.
My systems default Java is Java 7.
NetBeans-IDE was started with Java 8.
When I run the project via the IDE (Run project), the Project-Platform is used (which is Java 6).
I cannot change the Runtime Platform!
It's always: Project Platform
I tried to Manage Platforms..., but I still can't change the value of the Runtime Platform-ComboBox.
EDIT:
As I wrote in the comments, I don't want to change the Project-Platform.
The project should be compiled with Java 6 but run with Java 8 (when click on Run project).
What I want is:
Project-Platform = Java 6 (used to compile),
Runtime-Platform = Java 8 (used to run).
How can I change the Projects Runtime Platform?
Unfortunately you can't. As you point out, its value can only be Project Platform. Of course that invites the question "What is the point of even having that Runtime Platform field?".
I suspect that it may have been (unwisely) added to the GUI so that at some time in the future it will be possible to actually select a different JDK to run against. There is an open Bug Report for this: Bug 186747 - Can't Build and Run with Different Java Versions.
It's also worth noting that the Help documentation for the Run screen does not mention that Runtime Platform field. My own view is that the field should be removed until it serves a useful purpose.
What I want is: Project-Platform = Java 6 (used to compile),
Runtime-Platform = Java 8 (used to run).
Unfortunately that can't be done, as shown by the open bug. The best you can do right now is:
Create platforms for JDK 6 and JDK 8 in NetBeans.
Set the Java Platform to JDK 1.6 on the Libraries screen, and set the Source/Binary Format to JDK 6 on the Sources screen, then build to verify that no invalid APIs are being used.
Switch the Java Platform to 1.8 on the Libraries screen to run your 1.6 code under 1.8.
I realize that you don't want to do that, but unfortunately there's no silver bullet in the current release of NetBeans (8.2).
An alternative approach would be to build and run using only JDK 8, but include the Animal Sniffer Maven plugin "for checking projects against the signatures of an API", to verify that your 1.6 code was not using illegal APIs. But of course that's only viable for Maven projects.
Please look at Netbeans Project Setup - Setting the Target JDK in a Project
You just have to change the Runtime Platform at the Libraries option, that's all.
Just went through this pain for Apache NetBeans 14. I was trying to set a remote debug for a Raspberry Pi.
It works only if the jdk match on both the local and remote versions. In my case I set them both to 17.
I would have expected that the default jdk on the local machine should have been able to be changed but I fail to determine how.
I am running Ubuntu on the local machine so maybe the platform cannot be changed (don't know). Moving on.
Changed runtime platform
I have developed a Java Application in Eclipse using JDK 1.7.0, the application runs and everything works as expected.
Now I would like to send the application to a colleague of mine who is using a different version of the JDK. He is using 1.6.x.
I am not interested in him opening up the application and debugging through it in Eclipse. I would only like him to run it. If I make a runnable .jar of the application and send that to him, would it work even though he has a different JDK installed on his machine?
Thank You.
You need to compile it using JDK 1.6 (or lower). Provided your code doesn't use features from Java 7, you won't have to change anything in your sources
It would work if your colleague had a newer JRE than the JDK you used to compile it. All versions of JRE are backwards-compatible with all class files built with previous versions, but the opposite can clearly not work because new versions introduce new features. Your colleague will get an UnsupportedClassVersionError.
However, it is easy to set up in Eclipse the target class version for your project: go to Project Properties, Java Compiler, and under JDK Compliance choose the version 1.6.
Needless to say, this will fail if your source code uses any features or library calls which the version 6 does not support.