In order to change the JRE to be used by KNIME go to Eclipse
Preferences and select the
Afterwards you can add the right JRE. Under MacOs you choose the entry
MacOS X VM
then press next and select the right path, which should be
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home as shown here:
Finish and the right JRE will be added.
Afterwards you have to set the compiler options.
In order to do so go to
Project and select
Java Compiler and select the correct JRE at the
Compiler compliance level:
If you run the project now KNIME should start without problems.