private static void checkInitializerSource(String source) {
        String ex = "\\s*([A-Za-z0-9_$]+\\.)*[A-Za-z0-9_$]+.[A-Za-z0-9_$]+\\s*";
        if (!source.matches(ex)) {
            throwBadStatementException("Invalid java initializer expression: [" + source + "], " +
                    "A valid constructor initializer should be [ packageName.className ]");
        }
    }
This is a parser for custom aop pointcut expression.
<p>
Such as <pre>int android.util.Log.d(java.lang.String,java.lang.String)</pre>
plugin/src/main/groovy/com/didichuxing/tools/droidassist/spec/SourceSpec.java