How To Change Version Of Java In Eclipse

Details: Written by; Last Updated on 21 April 2020 | Impress E-mail

In this postal service, I will show you how to change Java version used to compile a project in Eclipse IDE. For case, y'all take to maintain an Eclipse projection was developed at the time of Java 1.8. At present you want to upgrade the project to be compiled with Java 11.

To summary, here are the steps to modify Java compiler version for a project in Eclipse IDE:

Install JRE/JDK that supports the Java version you desire to use.
Add that JRE/JDK to Eclipse's list of installed JREs
Update Java Build Path for the project, pointing to the new JRE/JDK
Modify Java compiler compliance level.

You can skip the steps ane and 2 if your project is already configured with JRE/JDK that supports the Java version to which y'all desire to alter.

Earlier going into each footstep in details, I think information technology's worth to sympathize some groundwork data kickoff.

You lot know, JDK provides the javac tool for compiling Java source code simply Eclipse doesn't use javac. Instead, Eclipse uses its own internal compiler to provide more than advanced features like incremental compilation – for apace compiling only small changes yous have made – not recompile the full project.

And Eclipse compiler requires JRE to run its compiled .class files. That's why it's not necessarily to have JDK to employ Eclipse - but JRE is enough.

Note that the JRE that runs Eclipse IDE is not necessarily the i that is used past Eclipse compiler. You can have your Eclipse running under JRE 11 simply the project is compiled with JRE 8.

Now, suppose that yous take a projection that is set to compile with Java 1.viii. To know Java compiler settings, right-click on the projection and click Properties. In the Properties dialog, navigate to Java Compiler section and you will come across the post-obit screen:

default java compiler 1.8 in eclipse

To alter version of Coffee compiler for your project, uncheck "Apply compliance from execution environment…", the yous tin choose Coffee version from the dropdown list equally below:

change java compiler compliance level

Alter compiler compliance level from one.viii to eleven – you will see a alert from Eclipse:

eclipse warning compiler level

This warning means that no uniform JRE for Coffee 11 configured in Eclipse. And then click the hyperlink Installed JREs, which pops up the following dialog:

eclipse installed JREs

Click Add together push. The next popup dialog appears:

eclipse add jre

Make sure Standard VM is selected, and click Next. And in the adjacent screen, click Directory to browse to JDK dwelling or JRE home that supports the Java compiler version yous want:

add JRE home in eclipse

Here, you can encounter I choose JDK 14 home directory. Click Finish. And bank check the newly added JRE/JDK:

eclipse check new installed JRE

Click Apply and Close. At present in the projection properties dialog, navigate to the Coffee Build Path section:

eclipse java build path

Select the JRE under Classpath and click Edit. Now, in the popup screen you tin can cull the execution environment for the JDK that supports the Java version y'all want to compile your project:

eclipse jre system library

Click Stop, and click Apply and close to employ compiler setting alter and dismiss the project properties dialog. And so you're all set.

NOTES: The Java compiler compliance level you can ready depends on the version of Eclipse'southward internal compiler. For example, Eclipse 2018-12 supports compilation of Java 11 and older versions even when you set to utilise JRE 14.

Watch the video:

About the Writer:

Nam Ha Minh is certified Java programmer (SCJP and SCWCD). He started programming with Coffee in the time of Coffee 1.4 and has been falling in honey with Java since and so. Make friend with him on Facebook and watch his Coffee videos yous YouTube.