On our project it was decided to upgrade to java8. However it seems not quick deal as we're using Spring 3.1.x, Tomcat 6.x, PowerMock tests and other legacy stuff. In order to quickly do it we have only one solution compile our project against Java 7 and run it on Java 8.
I know that "is something compiled as example for Java 5" then it can be safely used on any Java runtime starting from Java 5 and up, but it will fail with a "unsupported major class version" error on Java 1.4 runtimes or even below.
Is that a good practice at all ? Especially I am interested in a good references that it can be safely used or understand the risk against it.
Did anybody face with some problems ?