Examples for Chapter 15 - RESTful Java with JAX-RS 2.0 - page 359

}
The first invocation succeeds, but the second fails because we are allowed to invoke this
method only once per day.

Build and Run the Example Program
Perform the following steps:

1. Open a command prompt or shell terminal and change to the ex15_1 directory of the
workbook example code.
2. Make sure your PATH is set up to include both the JDK and Maven, as described in
Chapter 17 .
3. Perform the build and run the example by typing maven install .

Example ex15_1: JSON Web Encryption
In Chapter 15 , you learned a little bit about JSON Web Encryption (JWE) and how it can be
used to encrypt HTTP message body or header values. This example augments the customer
chat client implemented in Chapter 27 . Chat clients will use a shared secret to encrypt and
decrypt the messages they send to and receive from the chat server. Chat clients that know
the shared secret see the decrypted message, while clients that don't know it see only the
JWE encoding. Let's take a look at the code:

src/main/java/ChatClient.java

public public class class ChatClient ChatClient

{

public public static static void void main ( String [] args ) throws throws Exception

{

String name = args [ 0 ];
final final String secret = args [ 1 ];

The ChatClient first starts out by storing the name and secret password that the client will
use. It obtains these values from the command line.

final final Client client = new new ResteasyClientBuilder ()

. connectionPoolSize ( 3 )
. build ();
WebTarget target = client . target ( "http://localhost:8080/services/chat" );

target . request (). async (). get ( new new InvocationCallback < Response >()

{

@Override