问在通过方法创建对象时遇到的自动连接问题

EN

    CharArrayReader reader = new CharArrayReader(acCode.toCharArray());
    CharStream charStream = new CharStream(reader);
    Scanner scanner = new Scanner(charStream);
    TokenStream tokenStream = new TokenStream(scanner);
    ParserGeneratingAST parserGeneratingAST = new ParserGeneratingAST(tokenStream);
--> AbstractSyntaxTree ast = parserGeneratingAST.generateAST(); <-- here is the problem
    SymbolsTable symbolsTable = new SymbolsTable();
    ErrorsTable errorsTable = new ErrorsTable();

    SymbolsTableFillerVisitor symbolsTableFillerVisitor = new SymbolsTableFillerVisitor(symbolsTable, errorsTable);
    TypeCheckingVisitor typeCheckingVisitor = new TypeCheckingVisitor(symbolsTable, errorsTable);
    InstructionsList instructionsList = new InstructionsList();
    CodeGenerationVisitor codeGenerationVisitor = new CodeGenerationVisitor(instructionsList);

    symbolsTableFillerVisitor.visit(ast);
    typeCheckingVisitor.visit(ast);
    codeGenerationVisitor.visit(ast);        

AbstractSyntaxTree ast = parserGeneratingAST.generateAST();