Java jersey client API

gistfile1.java

package tw.org.iii.cosa.javabacked.rest;

import java.util.Iterator;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.core.util.MultivaluedMapImpl;

/**
 * Simple Jersey rest client bypassing cosa REST
 * 
 * @author kenwctsai
 **/
public class RESTClient {

	private static Log LOGGER = LogFactory.getLog(RESTClient.class);

	// jersey client
	private Client client;
	private WebResource webResource;
	private WebResource.Builder webResourceBuild;
	private ClientResponse clientResp;

	private MultivaluedMap<String, String> headersMap;

	public RESTClient() {
		this.headersMap = new MultivaluedMapImpl();
	}

	public int getStatus() {
		return this.clientResp.getStatus();
	}

	public void addHeader(String headerName, String headerValue) {
		LOGGER.debug("add header as below");
		LOGGER.debug(String.format("%s = %s%n", headerName, headerValue));

		this.headersMap.add(headerName, headerValue);
	}

	public String post(String apiURL, String jsonBody) {
		LOGGER.debug("use post to call api:" + apiURL);

		String response = null;

		this.client = Client.create();
		// create resource
		this.webResource = this.client.resource(apiURL);

		this.webResourceBuild = webResource.type(MediaType.APPLICATION_JSON)
				.accept(MediaType.APPLICATION_JSON);

		addHeaders();

		// do post
		this.clientResp = this.webResourceBuild.post(ClientResponse.class,
				jsonBody);

		if (this.clientResp.getStatus() == 200) {
			// get string of response
			response = this.clientResp.getEntity(String.class);
			LOGGER.debug("post response:" + response);
		} else {
			LOGGER.error("fail to call api:" + apiURL);
		}

		return response;
	}

	public String get(String apiURL) {

		LOGGER.debug("use get to call api:" + apiURL);

		String response = null;

		this.client = Client.create();

		// create resource
		this.webResource = this.client.resource(apiURL);

		this.webResourceBuild = this.webResource.type(
				MediaType.APPLICATION_JSON).accept(MediaType.APPLICATION_JSON);

		addHeaders();

		// do get
		this.clientResp = this.webResourceBuild.get(ClientResponse.class);

		if (this.clientResp.getStatus() == 200) {
			// get string of response
			response = this.clientResp.getEntity(String.class);
			LOGGER.debug("get response:" + response);
		} else {
			LOGGER.error("fail to call api:" + apiURL);
		}

		return response;
	}

	private void addHeaders() {

		LOGGER.debug("start to add headers into web resource");
		if (this.headersMap.size() > 0) {
			for (Iterator<String> it = headersMap.keySet().iterator(); it
					.hasNext();) {
				String key = it.next();
				String value = headersMap.getFirst(key);
				LOGGER.debug(String.format("%s = %s%n", key, value));
				this.webResourceBuild = this.webResource.header(key, value);
			}
			//clear current headers
			this.headersMap.clear();
		}

	}
}