一个内置的编译器而不是 javac 。内置编译器显然不支持Java 8。

您可以为项目定义一个自定义构建器，它将调用您的 javac 。在项目的首选项中，转到Builders，添加一个新的自定义构建器（可以是Ant脚本或可执行程序），并禁用默认的内置Java构建器。

之后，使用您选择的JDK运行项目不应该是一个问题 - 将其添加到已安装的JRE首选项页面（如您所做）应该是足够的。 p>

I'm experimenting with the new jdk8 what is available here http://jdk8.java.net/lambda/

I'm able to compile and run my project from command line.

I'm also able to add this new JDK to Installed JREs in Eclipse. However, I'm not able to have Eclipse to compile and run the project with this JDK.

I'm trying to change the settings on Project Properties/Java Compiler but the Use [JDK] compliance from execution environment on the 'Java Build Path' checkbox is disabled and no matter whatever I click on this page, I cannot make it work.

I have Eclipse Platform Version: 3.7.1

Any ideas?

thx

Eclipse uses a built-in compiler rather than javac. The built-in compiler obviously doesn't support Java 8 yet.

You can define a custom builder for your project which will call your javac. In the project's preferences, go to "Builders", add a new custom builder (which can be either an Ant script or an executable program) and disable the default built-in Java builder.

Afterwards, running the project with the JDK of your choice shouldn't be a problem - adding it to the "Installed JREs" preference page (as you did) should be sufficient.