Imports are not part of the visited Spoon AST

[honghao12]

Describe the bug

I tried to access the import element through the ctimport filter, but it wasn't available

Source code you are trying to analyze/transform

package src.p4;

import src.p1.A;

import java.util.Date;

public class E implements D {
    public static int e = 5;
    protected final int d = 4;
    int a = 1;
    private final int c = 3;

    public E() {
        System.out.println("this is a constructor!");
    }

    @Override
    public void fun1() {
        // test fun1
        int b = 2;
        System.out.println("global:" + a);
        System.out.println("local:" + b);
    }

    @Override
    public void fun3() {
        Date date = new Date();
        A a1 = new A();
        a1.m1();
        long time = date.getTime();
        System.out.println("time:" + time);
    }

    public final void fun2() {
        System.out.println("final fun!!");
    }
}

Source code for your Spoon processing

Launcher launcher = new Launcher();
  launcher.getEnvironment().setComplianceLevel(11);
  launcher.getEnvironment().setAutoImports(true);
  launcher.addInputResource("D:\\test\\FILE_STORY\\java\\javademo2\\src\\p4\\E.java");
  CtModel model = launcher.buildModel();

  List<CtImport> imports = model.getElements(new TypeFilter<>(CtImport.class));
  System.out.println("size:"+imports.size());

Actual output

size:0

Expected output

size:2

Spoon Version

10.3.0

JVM Version

11

What operating system are you using?

win10

[I-Al-Istannen]

Let me first add some meta-commentary. I am not sure why you need to do this, there might be a better way to achieve your goal. Spoon handles imports on its own normally, with you rarely needing to even be aware of their existence. Spoon will add imports as needed (and also delete them if allowed) if you pretty-print the model or use type.toStringWithImports().
If you talk a bit more about your goal, we might find a nicer solution.

---

Now for your question: This is a consequence of the visitor never descending into compilation units, and subsequently not into imports.
I am not aware of a really nice way to work around this, but you can do something like

	@Test
	void foo() {
		Launcher launcher = new Launcher();
		launcher.addInputResource(new VirtualFile("import java.util.List; class Foo { List<?> list; }"));
		CtType<?> type = launcher.buildModel().getAllTypes().iterator().next();
		for (CtImport anImport : type.getPosition().getCompilationUnit().getImports()) {
			anImport.accept(new CtAbstractImportVisitor() {
				// Just one example override
				@Override
				public <T> void visitTypeImport(CtTypeReference<T> typeReference) {
					System.out.println("Heya " + typeReference);
				}
			});
		}
	}

Note that this will fail if your type does not belong to a compilation unit (e.g. was created using Spoon itself and not parsed from disk). You can get a compilation unit for those types using factory.CompilationUnit().getOrCreate(type).