Today, it is recognized that reverse-engineering activities play an important role in round-trip development and software maintenance. However, the precision of most existing reverseengineering tools cannot meet the requirements of developers and maintainers, thus hampering understanding of software implementation. This paper presents an approach for recovering the UML class diagram from the Java source code, which traverses abstract syntax trees (AST) with the Visitor pattern to build the corresponding UML model elements. The source code is completely and systematically analyzed by this approach. As a result, the precision of the generated design model will be substantially promoted