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Using HttpClient, you can connect to a website which needed username and password. This chapter explains, how to execute a client request against a site that asks for username and password.
Step 1 – Create a CredentialsProvider object
The CredentialsProvider Interface maintains a collection to hold the user login credentials. You can create its object by instantiating the BasicCredentialsProvider class, the default implementation of this interface.
CredentialsProvider credentialsPovider = new BasicCredentialsProvider();
Step 2 – Set the Credentials
You can set the required credentials to the CredentialsProvider object using the setCredentials() method.
This method accepts two objects as given below −
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AuthScope object − Authentication scope specifying the details like hostname, port number, and authentication scheme name.
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Credentials object − Specifying the credentials (username, password).
Set the credentials using the setCredentials() method for both host and proxy as shown below −
credsProvider.setCredentials(new AuthScope("example.com", 80), new UsernamePasswordCredentials("user", "mypass")); credsProvider.setCredentials(new AuthScope("localhost", 8000), new UsernamePasswordCredentials("abc", "passwd"));
Step 3 – Create a HttpClientBuilder Object
Create a HttpClientBuilder using the custom() method of the HttpClients class.
//Creating the HttpClientBuilder HttpClientBuilder clientbuilder = HttpClients.custom();
Step 4 – Set the credentialsPovider
You can set the above created credentialsPovider object to a HttpClientBuilder using the setDefaultCredentialsProvider() method.
Set the CredentialProvider object created in the previous step to the client builder by passing it to the CredentialsProvider object() method as shown below.
clientbuilder = clientbuilder.setDefaultCredentialsProvider(credsProvider);
Step 5 – Build the CloseableHttpClient
Build the CloseableHttpClient object using the build() method of the HttpClientBuilder class.
CloseableHttpClient httpclient = clientbuilder.build()
Step 6 – Create a HttpGet object and execute it
Create a HttpRequest object by instantiating the HttpGet class. Execute this request using
the execute() method.
//Creating a HttpGet object HttpGet httpget = new HttpGet("https://www.tutorialspoint.com/ "); //Executing the Get request HttpResponse httpresponse = httpclient.execute(httpget);
Example
Following is an example program which demonstrates the execution of a HTTP request against a target site that requires user authentication.
import org.apache.http.Header; import org.apache.http.HttpResponse; import org.apache.http.auth.AuthScope; import org.apache.http.auth.Credentials; import org.apache.http.auth.UsernamePasswordCredentials; import org.apache.http.client.CredentialsProvider; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.BasicCredentialsProvider; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; public class UserAuthenticationExample { public static void main(String args[]) throws Exception{ //Create an object of credentialsProvider CredentialsProvider credentialsPovider = new BasicCredentialsProvider(); //Set the credentials AuthScope scope = new AuthScope("https://www.tutorialspoint.com/questions/", 80); Credentials credentials = new UsernamePasswordCredentials("USERNAME", "PASSWORD"); credentialsPovider.setCredentials(scope,credentials); //Creating the HttpClientBuilder HttpClientBuilder clientbuilder = HttpClients.custom(); //Setting the credentials clientbuilder = clientbuilder.setDefaultCredentialsProvider(credentialsPovider); //Building the CloseableHttpClient object CloseableHttpClient httpclient = clientbuilder.build(); //Creating a HttpGet object HttpGet httpget = new HttpGet("https://www.tutorialspoint.com/questions/index.php"); //Printing the method used System.out.println(httpget.getMethod()); //Executing the Get request HttpResponse httpresponse = httpclient.execute(httpget); //Printing the status line System.out.println(httpresponse.getStatusLine()); int statusCode = httpresponse.getStatusLine().getStatusCode(); System.out.println(statusCode); Header[] headers= httpresponse.getAllHeaders(); for (int i = 0; i<headers.length;i++) { System.out.println(headers[i].getName()); } } }
Output
On executing, the above program generates the following output.
GET HTTP/1.1 200 OK 200
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