将Java从版本8降级到7 [英] Downgrade java from version 8 to 7

问题描述

我已经在Ubuntu上从Oracle安装了Java 1.8，因为它是最好的，与先前版本兼容的最新版本.但事实并非如此. javac 1.8仅在java-8-oracle上生成可运行的字节码，scala无法运行.

I have installed Java 1.8 from Oracle on Ubuntu because I though it would be best, newest version compatible with previous ones. But it is not. javac 1.8 produces bytecode runnable only on the java-8-oracle, scala does not run.

在升级之前，我使用的是java-7-openjdk，一切都很好.尽管 我可以使用sudo update-alternatives --config java选择较旧的虚拟机，但是我还需要能够选择较旧的编译器. 我该怎么办?

Before upgrade I was using java-7-openjdk, everything was fine. While I can choose my older virtual machine using sudo update-alternatives --config java, but I also need to be able to choose older compiler. How can I do this?

推荐答案

使用-target标志生成早期版本的字节码.例如. javac -target 1.5 FooBar.java.

Use the -target flag to generate bytecode for earlier version. E.g. javac -target 1.5 FooBar.java.

无需降级.

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