Programmers must implement the {@link com.sun.net.httpserver.HttpHandler} interface. This interface provides a callback which is invoked to handle incoming requests from clients. A HTTP request and its response is known as an exchange. HTTP exchanges are represented by the {@link com.sun.net.httpserver.HttpExchange} class. The {@link com.sun.net.httpserver.HttpServer} class is used to listen for incoming TCP connections and it dispatches requests on these connections to handlers which have been registered with the server.
A minimal Http server example is shown below:
class MyHandler implements HttpHandler {
public void handle(HttpExchange t) throws IOException {
InputStream is = t.getRequestBody();
read(is); // .. read the request body
String response = "This is the response";
t.sendResponseHeaders(200, response.length());
OutputStream os = t.getResponseBody();
os.write(response.getBytes());
os.close();
}
}
...
HttpServer server = HttpServer.create(new InetSocketAddress(8000));
server.createContext("/applications/myapp", new MyHandler());
server.setExecutor(null); // creates a default executor
server.start();
The example above creates a simple HttpServer which uses the calling application thread to invoke the handle() method for incoming http requests directed to port 8000, and to the path /applications/myapp/.
The {@link com.sun.net.httpserver.HttpExchange} class encapsulates everything an application needs to process incoming requests and to generate appropriate responses.
Registering a handler with a HttpServer creates a {@link com.sun.net.httpserver.HttpContext} object and {@link com.sun.net.httpserver.Filter} objects can be added to the returned context. Filters are used to perform automatic pre- and post-processing of exchanges before they are passed to the exchange handler.
For sensitive information, a {@link com.sun.net.httpserver.HttpsServer} can be used to process "https" requests secured by the SSL or TLS protocols. A HttpsServer must be provided with a {@link com.sun.net.httpserver.HttpsConfigurator} object, which contains an initialized {@link javax.net.ssl.SSLContext}. HttpsConfigurator can be used to configure the cipher suites and other SSL operating parameters. A simple example SSLContext could be created as follows:
char[] passphrase = "passphrase".toCharArray();
KeyStore ks = KeyStore.getInstance("JKS");
ks.load(new FileInputStream("testkeys"), passphrase);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(ks, passphrase);
TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
tmf.init(ks);
SSLContext ssl = SSLContext.getInstance("TLS");
ssl.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);
In the example above, a keystore file called "testkeys", created with the keytool utility is used as a certificate store for client and server certificates. The following code shows how the SSLContext is then used in a HttpsConfigurator and how the SSLContext and HttpsConfigurator are linked to the HttpsServer.
server.setHttpsConfigurator (new HttpsConfigurator(sslContext) {
public void configure (HttpsParameters params) {
// get the remote address if needed
InetSocketAddress remote = params.getClientAddress();
SSLContext c = getSSLContext();
// get the default parameters
SSLParameters sslparams = c.getDefaultSSLParameters();
if (remote.equals (...) ) {
// modify the default set for client x
}
params.setSSLParameters(sslparams);
// statement above could throw IAE if any params invalid.
// eg. if app has a UI and parameters supplied by a user.
}
});
@since 1.6 */ package com.sun.net.httpserver;