com.groiss.http

Class Client

java.lang.Object

com.groiss.http.Client

All Implemented Interfaces:

AutoCloseable

public class Client
extends Object
implements AutoCloseable

This class is designed to be used in any case you need to communicate with another server using the HTTP protocol. It provides easy-to-use methods for those use cases we identified as being the most common ones (e.g. a GET or POST request with some parameters). For all other methods a more generic (and therefore not so handy) method is provided.

Additionally it hides the need for caring about how data (parameters or other payload) will be transfered to that server, how it needs to be encoded, etc.

For aspects common to (almost) all of your client-server-calls you can use a ClientConfiguration object, e.g. for setting a base url for that server or for setting an authorization token that needs always to be passed of for setting an url prefix.

A typical usage of this class could be like that:

 private static ClientConfiguration config = new ClientConfiguration().setBaseUrl("http://mytestserver/myrestbase/");

 protected JSONObject myGet(String myRestId) throws Exception {
    try (Client client = new Client(config); Response res = client.get("myrestmethod/" + myRestId)) {
       if (res.getStatusCode() == 200) {
          return res.getJSONObjectResult();
       }
       throw new ApplicationException("Unsupported status code: " + res.getStatusCode() + " - " + res.getStatusMessage());
    }
 }

 protected JSONObject myPost(String id) throws Exception {
    try (Client client = new Client(config);
       Response res = client.post("myrestmethod/", new Parameter("id", id), new Parameter("name", name))) {
       if (res.getStatusCode() == 200) {
          return res.getJSONObjectResult();
       }
       throw new ApplicationException("Unsupported status code: " + res.getStatusCode() + " - " + res.getStatusMessage());
    }
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Client.Method the HTTP methods supported by this client

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.http.impl.client.HttpClientBuilder	clientBuilder
protected ClientConfiguration	config the configuration object for this client
protected static String	DEFAULT_CHARSET the default characters set to be used if not other is specified
protected org.apache.http.impl.client.CloseableHttpClient	httpClient
protected static org.slf4j.Logger	logger
protected String	requestAsString

Constructor Summary

Constructors

Constructor and Description
Client() creates a new client
Client(ClientConfiguration config) creates a new client based on the passed configuration

Method Summary

Modifier and Type	Method and Description
void	close() Closes the client and releases all resources.
Response	delete(String url, Object payload, Parameter... params) Executes a DELETE request on the passed url using the passed payload and parameters
Response	delete(String url, Parameter... params) Executes a DELETE request on the passed url using the passed parameters
protected org.apache.http.client.methods.CloseableHttpResponse	execute(Client.Method method, String url, Map<String,String> headers, Object payload, Parameter... params) Executes a request based on the specified parameters:
Response	executeRequest(Client.Method method, String url, Map<String,String> headers, Object payload, Parameter... params) Executes a request based on the specified parameters:
Response	get(String url, Parameter... params) Executes a GET request on the passed url using the passed parameters
protected org.apache.http.client.methods.HttpRequestBase	getClientForMethod(Client.Method method) Returns the request implementation for the passed method
protected void	init() this method initializes the client based on the passed configuration object
Response	post(String url, Object payload, Parameter... params) Executes a POST request on the passed url using the passed payload and parameters
Response	post(String url, Parameter... params) Executes a POST request on the passed url using the passed parameters
Response	put(String url, Object payload, Parameter... params) Executes a PUT request on the passed url using the passed payload and parameters
Response	put(String url, Parameter... params) Executes a PUT request on the passed url using the passed parameters
String	toString() Returns a string representation of the request that should be executed by this client.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

logger

protected static org.slf4j.Logger logger

DEFAULT_CHARSET

protected static final String DEFAULT_CHARSET

the default characters set to be used if not other is specified

See Also:

Constant Field Values

config

protected ClientConfiguration config

the configuration object for this client

httpClient

protected org.apache.http.impl.client.CloseableHttpClient httpClient

clientBuilder

protected org.apache.http.impl.client.HttpClientBuilder clientBuilder

requestAsString

protected String requestAsString

Constructor Detail

Client

public Client()

creates a new client

Client

public Client(ClientConfiguration config)

creates a new client based on the passed configuration

Parameters:

config - the configuration for this client

Method Detail

init

protected void init()

this method initializes the client based on the passed configuration object

close

public void close()

Closes the client and releases all resources. If the client is already closed then invoking this method has no effect.

Specified by:

close in interface AutoCloseable

toString

public String toString()

Returns a string representation of the request that should be executed by this client. Will be null if request could not be created.

Overrides:

toString in class Object

delete

public Response delete(String url,
                       Parameter... params)

Executes a DELETE request on the passed url using the passed parameters

Parameters:

url - the url of the request

params - the parameters for the request

Returns:

the response of the request

delete

public Response delete(String url,
                       Object payload,
                       Parameter... params)

Executes a DELETE request on the passed url using the passed payload and parameters

Parameters:

url - the url of the request

payload - the payload for the request (e.g. a file, for more details see executeRequest(Method, String, Map, Object, Parameter...))

params - the parameters for the request

Returns:

the response of the request

get

public Response get(String url,
                    Parameter... params)

Executes a GET request on the passed url using the passed parameters

Parameters:

url - the url of the request

params - the parameters for the request

Returns:

the response of the request

post

public Response post(String url,
                     Parameter... params)

Executes a POST request on the passed url using the passed parameters

Parameters:

url - the url of the request

params - the parameters for the request (sent as form parameters)

Returns:

the response of the request

post

public Response post(String url,
                     Object payload,
                     Parameter... params)

Executes a POST request on the passed url using the passed payload and parameters

Parameters:

url - the url of the request

payload - the payload for the request (e.g. a file, for more details see executeRequest(Method, String, Map, Object, Parameter...))

params - the parameters for the request

Returns:

the response of the request

put

public Response put(String url,
                    Parameter... params)

Executes a PUT request on the passed url using the passed parameters

Parameters:

url - the url of the request

params - the parameters for the request

Returns:

the response of the request

put

public Response put(String url,
                    Object payload,
                    Parameter... params)

Executes a PUT request on the passed url using the passed payload and parameters

Parameters:

url - the url of the request

payload - the payload for the request (e.g. a file, for more details see executeRequest(Method, String, Map, Object, Parameter...))

params - the parameters for the request

Returns:

the response of the request

executeRequest

public Response executeRequest(Client.Method method,
                               String url,
                               Map<String,String> headers,
                               Object payload,
                               Parameter... params)

Executes a request based on the specified parameters:

Parameters:

method - the method of the request (e.g. GET or HEAD)

url - the url of the request

headers - headers for the request. This is only needed if the default settings are not appropriate or do not contain the needed header property

payload - the payload of the request. By now we provide support for a File, a JSONObject or a JSONArray. For every other type of payload you need to specify the 'Content-Type' on your own and the toString()-result of your payload must match with that content type.

params - the parameters for the request. In case of POST, PATCH and PUT the parameters will be sent as form parameters, otherwise they will be sent as request parameters.

Returns:

the response of the request

execute

protected org.apache.http.client.methods.CloseableHttpResponse execute(Client.Method method,
                                                                       String url,
                                                                       Map<String,String> headers,
                                                                       Object payload,
                                                                       Parameter... params)

Executes a request based on the specified parameters:

Parameters:

method - the method of the request (e.g. GET or HEAD)

url - the url of the request

headers - headers for the request. This is only needed if the default settings are not appropriate or do not contain the needed header property

payload - the payload of the request. By now we support a File, a JSONObject or a JSONArray. For every other payload you need to specify the 'Content-Type' on your own and the toString()-result of your payload must match with that content type.

params - the parameters for the request. In case of POST, PATCH and PUT the parameters will be sent as form parameters, otherwise they will be sent as request parameters.

Returns:

the response of the request

getClientForMethod

protected org.apache.http.client.methods.HttpRequestBase getClientForMethod(Client.Method method)

Returns the request implementation for the passed method

Parameters:

method - the method of the request

Returns:

the appropriate request implementation