added code examples

http-clients/src/main/java/io/pratik/OkHttpClientApp.java

@@ -0,0 +1,95 @@
+/**
+ * 
+ */
+package io.pratik;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.HashMap;
+import java.util.concurrent.TimeUnit;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import okhttp3.Call;
+import okhttp3.Callback;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class OkHttpClientApp {
+	
+	public void invoke() throws URISyntaxException, IOException {
+	    OkHttpClient client = new OkHttpClient.Builder()
+			    .readTimeout(1000, TimeUnit.MILLISECONDS)
+			    .writeTimeout(1000, TimeUnit.MILLISECONDS)
+			    .build();
+
+		Request request = new Request.Builder()
+			.url(URLConstants.URL)
+			.get()
+			.addHeader(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE)
+			.build();
+
+		Call call = client.newCall(request);
+		call.enqueue(new Callback() {
+	        public void onResponse(Call call, Response response) 
+	          throws IOException {
+	        	System.out.println(response.body().string());
+	        }
+	        
+	        public void onFailure(Call call, IOException e) {
+	            // error
+	        }
+	    });
+		
+	}
+	
+	public void invokePost() throws URISyntaxException, IOException {
+	    OkHttpClient client = new OkHttpClient.Builder()
+			    .readTimeout(1000, TimeUnit.MILLISECONDS)
+			    .writeTimeout(1000, TimeUnit.MILLISECONDS)
+			    .build();
+	    
+		String requestBody = prepareRequest();
+
+	    RequestBody body = RequestBody.create(
+	      requestBody,
+	      MediaType.parse("application/json"));
+	    
+		Request request = new Request.Builder()
+			.url("https://reqbin.com/echo/post/json")
+			.post(body)
+			.addHeader(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE)
+			.build();
+
+		Response response = client.newCall(request).execute();
+		System.out.println(response.body().string());
+	}
+
+	private String prepareRequest() throws JsonProcessingException {
+		var values = new HashMap<String, String>() {
+			{
+				put("Id", "12345");
+				put("Customer", "Roger Moose");
+				put("Quantity", "3");
+				put("Price","167.35");
+			}
+		};
+
+		var objectMapper = new ObjectMapper();
+		String requestBody = objectMapper.writeValueAsString(values);
+		return requestBody;
+	}
+	
+	public static void main(String[] args) throws URISyntaxException, IOException {
+		new OkHttpClientApp().invokePost();
+	}
+
+}