Client Configuration
The RestClient configuration is performed by using the ClientConfig class. An instance of the configuration class is passed to the constructor of the RestClient when constructing a new RestClient.
The following options can be configured in the RestClient:
- Custom providers via JAX-RS Application
- Handler chain
- Proxy host and port
- Connect and read timeouts
- Redirect
Handler Configuration
The following example demonstrates how to register a custom handler.
1 ClientConfig config = new ClientConfig();
// Create new JAX-RS Application
2 config.handlers(new DummyHandler());
// create the rest client instance
3 RestClient client = new RestClient(config);
// create the resource instance to interact with
4 Resource resource = client.resource("http://services.com/HelloWorld");
// perform a GET on the resource
// the resource will be returned as plain text
5 String response = resource.accept("text/plain").get(String.class);
Explanation
First, a new instance of a ClientConfig is created as it appears in line 1. Then the new handler is added to the handlers chain by invoking the handlers() method on the ClientConfig instance as it appears in line 2. Finally, a new instance of a RestClient is created with this configuration as it appears in line 3.
org.apache.wink.client.handlers.BasicAuthSecurityHandler
You can configure a simple BasicAuthSecurityHandler to use basic authentication when accessing resources from the client.
ClientConfig config = new ClientConfig();<br/>
BasicAuthSecurityHandler basicAuthHandler = new BasicAuthSecurityHandler();
basicAuthHandler.setUserName("foo");
basicAuthHandler.setPassword("bar");
config.handlers(basicAuthHandler);<br/>
// create the rest client instance<br/>
RestClient client = new RestClient(config);<br/>
// create the resource instance to interact with Resource<br/>
resource = client.resource("http://localhost:8080/path/to/resource");<br/>
Explanation
The BasicAuthSecurityHandler will attempt to access the resource without security information first. If the request is successful, then the BasicAuthSecurityHandler is like a no-op. However, if it receives a 401, then the username and password will be added to the request, and the request will be sent again.
See the source code for more information on configuration.
Gzip Input Stream Adapter
The following code snippet is an example of an implementation of a Gzip input stream adapter.
class GzipInputAdapter implements InputStreamAdapter{
public InputStream adapt(InputStream is,
ClientResponse response) {
String header = response.getHeaders().getFirst("Content-Encoding");
if (header != null && header.equalsIgnoreCase("gzip")) {
return new GZIPInputStream(is);
}
return is;
}}
Explanation
The Gzip input stream adapter is responsible for wrapping the input stream with the Gzip input stream.
Gzip Output Stream Adapter
The following code snippet is an example of an implementation of a Gzip output stream adapter.
class GzipOutputAdapter implements OutputStreamAdapter {
public OutputStream adapt(OutputStream os,
ClientRequest request) {
request.getHeaders().add("Content-Encoding", "gzip");
return new GZIPOutputStream(os);
}}
Explanation
The Gzip output stream adapter is responsible for wrapping the output stream with the Gzip output stream.
Custom Provider Configuration
The following example demonstrates how to register a custom entity provider.
1 ClientConfig config = new ClientConfig();
// Create new JAX-RS Application
2 Application app = new Application() {
@Override
public Set<Class<?>> getClasses() {
HashSet<Class<?>> set = new HashSet<Class<?>>();
set.add(FooProvider.class);
return set;}};
3 conf.applications(app);
// create the rest client instance
4 RestClient client = new RestClient(config);
// create the resource instance to interact with
5 Resource resource = client.resource("http://services.com/HelloWorld");
// perform a GET on the resource. the resource will be returned as plain text
6 String response = resource.accept("text/plain").get(String.class);
Explanation
First, a new instance of ClientConfig is created as it appears in line 1. Then a new anonymous Application is instantiated and set on the ClientConfig as it appears in line 2 and 3. Finally, a new instance of a RestClient is created with this configuration as it appears in line 4.