Bug 70284 [1.5] class file with "1.4 compatibility" cannot be run in Java 1.4
If I compile a simple class in Eclipse with the following compliance settings, it won't run in a 1.4 JVM. It appears the .class file relies on 1.5 libraries, despite the compatibility setting. Compiler compliance: 1.5 Generated .class compatibility: 1.4 Source compatibility: 1.5 Here's my source code: public class TestConcat { public static void main(String[] args) { String w = "world"; System.out.println("Hello " + w); } } The resulting exception: Exception in thread "main" java.lang.NoClassDefFoundError: java/lang/StringBuilder at TestConcat.main(TestConcat.java:13)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/CompilerConfigurationBlock.java
Composite extraComposite= create15TabContent(folder);
		
		item= new TabItem(folder, SWT.NONE);
		item.setText(PreferencesMessages.getString("CompilerConfigurationBlock.15.tabtitle")); 
		item.setControl(extraComposite);		
		
		validateSettings(null, null);
	
		return folder;
	}
	private Composite createStyleTabContent(Composite folder) {
		String[] errorWarningIgnore= new String[] { ERROR, WARNING, IGNORE };
		
		String[] errorWarningIgnoreLabels= new String[] {
			PreferencesMessages.getString("CompilerConfigurationBlock.error"),  
			PreferencesMessages.getString("CompilerConfigurationBlock.warning"), 
			PreferencesMessages.getString("CompilerConfigurationBlock.ignore") 
		};
		
		int nColumns= 3;
		
		GridLayout layout= new GridLayout();
		layout.numColumns= nColumns;
		Composite composite= new Composite(folder, SWT.NULL);
		composite.setLayout(layout);
		
		Label description= new Label(composite, SWT.WRAP);
		description.setText(PreferencesMessages.getString("CompilerConfigurationBlock.common.description")); 
		GridData gd= new GridData();
		gd.horizontalSpan= nColumns;