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java.lang.Object | +--gnu.crypto.tool.SimpleCallbackHandler
A simple CallbackHandler for test purposes.
| Constructor Summary | |
|---|---|
SimpleCallbackHandler()
|
|
| Method Summary | |
|---|---|
void |
handle(Callback[] callbacks)
Retrieve or display the information requested in the provided Callbacks. |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
public SimpleCallbackHandler()
| Method Detail |
public void handle(Callback[] callbacks)
throws java.io.IOException,
UnsupportedCallbackException
CallbackHandlerRetrieve or display the information requested in the provided
Callbacks.
The handle() method implementation checks the instance(s)
of the Callback object(s) passed in to retrieve or display the
requested information. The following example is provided to help
demonstrate what an handle() method implementation might look
like. This example code is for guidance only. Many details, including
proper error handling, are left out for simplicity.
public void handle(Callback[] callbacks)
throws IOException, UnsupportedCallbackException {
for (int i = 0; i < callbacks.length; i++) {
if (callbacks[i] instanceof TextOutputCallback) {
// display the message according to the specified type
TextOutputCallback toc = (TextOutputCallback)callbacks[i];
switch (toc.getMessageType()) {
case TextOutputCallback.INFORMATION:
System.out.println(toc.getMessage());
break;
case TextOutputCallback.ERROR:
System.out.println("ERROR: " + toc.getMessage());
break;
case TextOutputCallback.WARNING:
System.out.println("WARNING: " + toc.getMessage());
break;
default:
throw new IOException("Unsupported message type: "
+ toc.getMessageType());
}
} else if (callbacks[i] instanceof NameCallback) {
// prompt the user for a username
NameCallback nc = (NameCallback)callbacks[i];
// ignore the provided defaultName
System.err.print(nc.getPrompt());
System.err.flush();
nc.setName((new BufferedReader(
new InputStreamReader(System.in))).readLine());
} else if (callbacks[i] instanceof PasswordCallback) {
// prompt the user for sensitive information
PasswordCallback pc = (PasswordCallback)callbacks[i];
System.err.print(pc.getPrompt());
System.err.flush();
pc.setPassword(readPassword(System.in));
} else {
throw new UnsupportedCallbackException(
callbacks[i], "Unrecognized Callback");
}
}
}
// Reads user password from given input stream.
private char[] readPassword(InputStream in) throws IOException {
// insert code to read a user password from the input stream
}
handle in interface CallbackHandlercallbacks - an array of Callback objects provided by an
underlying security service which contains the information requested to
be retrieved or displayed.
UnsupportedCallbackException - if the implementation of this method
does not support one or more of the Callbacks specified in the
callbacks parameter.
java.io.IOException - if an input or output error occurs.
|
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