private void visitJavaFileToPopulateCache(AccessibleObject methodOrConstructor) {
InputStream is = null;
try {
is = javaFileFinder.openJavaFile(methodOrConstructor);
if (is != null) {
// visit .java file using our custom GenericVisitorAdapter
CompilationUnit cu = JavaParser.parse(is);
MethodParametersVisitor visitor = new MethodParametersVisitor();
cu.accept(visitor, cache);
}
} catch (Exception e) {
throw new ParameterNamesNotFoundException(
"Error while trying to read parameter names from the Java file which contains the declaration of "
+ methodOrConstructor.toString(),
e);
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
// should never happen
}
}
}
}
/*
* (non-Javadoc)
*
* @see com.thoughtworks.paranamer.Paranamer#lookupParameterNames(java.lang.reflect
* .AccessibleObject, boolean)
*/
public String[] lookupParameterNames(
AccessibleObject methodOrConstructor, boolean throwExceptionIfMissing) {
if (methodOrConstructor == null) {
throw new NullPointerException("method or constructor to inspect cannot be null");
}
String[] result = cache.get(methodOrConstructor);
if (result == null) {
visitJavaFileToPopulateCache(methodOrConstructor);
result = cache.get(methodOrConstructor);
}
if (result == null && throwExceptionIfMissing) {
throw new ParameterNamesNotFoundException(
"Cannot retrieve parameter names for method " + methodOrConstructor.toString());
}
return result;
}