Java Reference
In-Depth Information
System
.
out
.
println
(
"Content-Type: "
+
response
.
getEntity
().
getContentType
().
getValue
());
BufferedReader reader
=
new
new
InputStreamReader
(
response
.
getEntity
()
.
getInputStream
()));
new
BufferedReader
(
new
String line
=
reader
.
readLine
();
while
while
(
line
!=
null
null
) {
System
.
out
.
println
(
line
);
line
=
reader
.
readLine
();
}
client
.
getConnectionManager
().
shutdown
();
}
}
In Apache HttpClient 4.x, the
org.apache.http.impl.client.DefaultHttpClient
class
is responsible for managing HTTP connections. It handles the default authentication settings,
and pools and manages persistent HTTP connections (keepalive) and any other default con-
figuration settings. It is also responsible for executing requests. The
org.apache.http.client.methods.HttpGet
class is used to build an actual HTTP GET
request. You initialize it with a URL and set any request headers you want using the
Ht-
tpGet.addHeader()
method. There are similar classes in this package for doing POST,
PUT, and DELETE invocations. Once you have built your request, you execute it by calling
DefaultHttpClient.execute()
, passing in the request you built. This returns an
org.apache.http.HttpResponse
object. To get the response code from this object, execute
HttpResponse.getStatusLine().getStatusCode()
. The
HttpResponse.getEntity()
method returns an
org.apache.http.HttpEntity
object, which represents the message
body of the response. From it, you can get the
Content-Type
by executing
Ht-
tpEntity.getContentType()
as well as a
java.io.InputStream
so you can read the re-
sponse. When you are done invoking requests, you clean up your connections by calling
Ht-
tpClient.getConnectionManager().shutdown()
.
To push data to the server via a POST or PUT operation, you need to encapsulate your data
within an instance of the
org.apache.http.HttpEntity
interface. The framework has
some simple prebuilt ones for sending strings, forms, byte arrays, and input streams. Let's
look at sending some XML.
In this example, we want to create a customer in a RESTful customer database. The API
works by POSTing an XML representation of the new customer to a specific URI. A suc-
