How to find whether a member variable is used in a method using code in eclipse jdt?

问题

I have to find all the methods in a class that use a particular member variable. (like "References" in eclipse but I want to implement using code...)I use AST visitor pattern that visits FieldDeclaration to get the name and type of all the member variables. I also use visitor pattern that visits MethodDeclaration nodes to get the content of each method using getBody(). Now I have the field variable name, type and member method details. I thought I can use a string search on the content of each member method but for a variable name "a", search may return true for keywords like "class" and others too!!! Is there a way to find the usage of a particular variable corresponding to a fieldDeclaration?? (like Binding or something??) If so, what is the AST Node or Class?

Here's the code I used...

 SimpleNameVisitor simpleNameVisitor=new SimpleNameVisitor();
 //SimpleNameVisitor is the visitor pattern for SimpleName
 simpleNameVisitor.process(mthd.getMethodBlock());
 //mthd is the object that stores method details
 for(SimpleName simpName:simpleNameVisitor.getIdentifiers()){
    if(varName.contentEquals(simpName.getFullyQualifiedName())){
        //varName is the field variable name
        System.out.println("MethodName: "+mthd.getName());
        return;
    }
  }

Here's the code that solved the problem(suggested by wjans;changed equals to contentEquals)

VariableDeclarationFragment fragment = ... ;
IBinding binding = fragment.getName().resolveBinding();


public boolean visitNode(SimpleName simpleName) throws Exception {
if (binding.toString().contentEquals(simpleName.resolveBinding().toString()) {
    ....
}

}

回答1:

You can do something like this:

Keep a reference to the binding of your FieldDeclaration,

VariableDeclarationFragment fragment = ... ;
IBinding binding = fragment.getName().resolveBinding();

and use this to compare it with the bindings when visiting SimpleName's inside your MethodDeclaration

public boolean visitNode(SimpleName simpleName) throws Exception {
    if (binding.equals(simpleName.resolveBinding()) {
        ....
    }
}   

回答2:

To implement something like Find References in code, use the JDT SearchEngine.

        SearchRequestor findMethod = new SearchRequestor() {
            @Override
            public void acceptSearchMatch(SearchMatch match) throws CoreException {
                // analyze search match.
            }
        };
        SearchEngine engine = new SearchEngine();
        IJavaSearchScope workspaceScope = SearchEngine
                .createWorkspaceScope();
        SearchPattern pattern = SearchPattern
                .createPattern(
                        "org.eclipse.e4.core.internal.contexts.EclipseContext.strategy",
                        IJavaSearchConstants.FIELD,
                        IJavaSearchConstants.REFERENCES,
                        SearchPattern.R_EXACT_MATCH);
        SearchParticipant[] participant = new SearchParticipant[] { SearchEngine
                .getDefaultSearchParticipant() };
        engine.search(pattern, participant, workspaceScope, findMethod,
                new NullProgressMonitor());

See http://help.eclipse.org/helios/index.jsp?topic=/org.eclipse.jdt.doc.isv/guide/jdt_int_core.htm for more details on java search, the java model, and the AST.

See https://bugs.eclipse.org/bugs/attachment.cgi?id=192205 for an example that uses search and then looks at the results by generating an AST.

回答3:

Visit all SimpleNames within the body of each method in your class:

public boolean visit(SimpleName node) {

    IBinding binding = node.resolveBinding();

    if (binding instanceof IVariableBinding) {

        IVariableBinding variable = (IVariableBinding) binding;

        if (variable.isField())

            //do whatever you wanna do with the field
            System.out.println("field: " + node.toString());

    }

    return super.visit(node);
}

来源：https://stackoverflow.com/questions/6016647/how-to-find-whether-a-member-variable-is-used-in-a-method-using-code-in-eclipse