Perhaps you can use Processing with Java 7 (try and move the jre folder somewhere else, to restore it if it doesn't work). I think it will detect and use the installed JRE. Although it needs the JDK, to use the compiler. You might need to set a JAVA_HOME environment variable to the path of the JDK (mine is set to C:\Java\jdk1.6.0_30 for example).

But be aware that new syntax won't be accepted in .pde files, which uses a parser specific to Processing (to exploit the syntax extensions, like the color type or the #ABCDEF literals). You can use it in .java files, though.