/**
* Returns an object that implements the given interface to allow access to non-standard methods,
* or standard methods not exposed by the proxy. The result may be either the object found to
* implement the interface or a proxy for that object. If the receiver implements the interface
* then that is the object. If the receiver is a wrapper and the wrapped object implements the
* interface then that is the object. Otherwise the object is the result of calling <code>unwrap
* </code> recursively on the wrapped object. If the receiver is not a wrapper and does not
* implement the interface, then an <code>SQLException</code> is thrown.
*
* @param iface A Class defining an interface that the result must implement.
* @return an object that implements the interface. May be a proxy for the actual implementing
* object.
* @throws java.sql.SQLException If no object found that implements the interface
* @since 1.6
*/
public synchronized <T> T unwrap(java.lang.Class<T> iface) throws java.sql.SQLException {
try {
if ("java.sql.Statement".equals(iface.getName())
|| "java.sql.PreparedStatement".equals(iface.getName())
|| "java.sql.Wrapper.class".equals(iface.getName())) {
return iface.cast(this);
}
if (unwrappedInterfaces == null) {
unwrappedInterfaces = new HashMap();
}
Object cachedUnwrapped = unwrappedInterfaces.get(iface);
if (cachedUnwrapped == null) {
if (cachedUnwrapped == null) {
cachedUnwrapped =
Proxy.newProxyInstance(
this.wrappedStmt.getClass().getClassLoader(),
new Class[] {iface},
new ConnectionErrorFiringInvocationHandler(this.wrappedStmt));
unwrappedInterfaces.put(iface, cachedUnwrapped);
}
unwrappedInterfaces.put(iface, cachedUnwrapped);
}
return iface.cast(cachedUnwrapped);
} catch (ClassCastException cce) {
throw SQLError.createSQLException(
"Unable to unwrap to " + iface.toString(),
SQLError.SQL_STATE_ILLEGAL_ARGUMENT,
this.exceptionInterceptor);
}
}
public <T> T unwrap(java.lang.Class<T> iface) throws java.sql.SQLException {
try {
// This works for classes that aren't actually wrapping anything
return iface.cast(this);
} catch (ClassCastException cce) {
throw SQLError.createSQLException("Unable to unwrap to " + iface.toString(), SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
}
}
private List<Class<?>> buildClassesList(
List<Class<?>> result, Set<String> seen, boolean publicOnly) {
for (Class<?> c = clazz; c != null; c = c.getSuperclass()) {
for (Class<?> f : c.getClassCache().getDeclaredClasses(false, publicOnly)) {
String s = f.toString();
if (!seen.contains(s)) {
result.add(f);
seen.add(s);
}
}
}
return result;
}
@NoInline
private void throwNoSuchMethodException(String name, Class<?>... parameterTypes)
throws NoSuchMethodException {
StringBuilder typeString;
if (parameterTypes == null || parameterTypes.length == 0) {
typeString = new StringBuilder("()");
} else {
typeString = new StringBuilder("(");
for (int i = 0; i < parameterTypes.length - 1; i++) {
Class<?> c = parameterTypes[i];
typeString.append(c.toString());
typeString.append(", ");
}
typeString.append(parameterTypes[parameterTypes.length - 1]);
typeString.append(')');
}
throw new NoSuchMethodException(name + typeString);
}
