BitfinexAccessor.java

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import java.io.IOException;

public class BitfinexAccessor {
    private static String urlOverHttps = "https://api.bitfinex.com/v1/pubticker/btcusd";
    private OkHttpClient client;
    private Exception exception;

    private double usdbtc;
    private long lastUSDBTCRespTime;

    public BitfinexAccessor() {
        this.client = new OkHttpClient();;
    }

    public synchronized double getUSDBTC() {
        if (lastUSDBTCRespTime + 60 * 1000 < System.currentTimeMillis()) {
            lastUSDBTCRespTime = System.currentTimeMillis();
            try {
                usdbtc = requestUSDBTC();
            } catch (Exception e) {
                e.printStackTrace();
                exception = e;
            }
            exception = null;
        }

        return usdbtc;
    }

    protected double requestUSDBTC() throws IOException {
        Request request = new Request.Builder()
                .url(urlOverHttps)
                .build();

        Response response = client.newCall(request).execute();

        ObjectMapper objectMapper = new ObjectMapper();
        JsonNode jsonNode = objectMapper.readTree(response.body().string());
        return jsonNode.get("last_price").asDouble();
    }

    public synchronized long getUSDBTCUpdateTime() {
        return lastUSDBTCRespTime;
    }

    public synchronized Exception getException() {
        return exception;
    }
}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>ru.zuma</groupId>
  <artifactId>BitfinexArtem</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>BitfinexArtem Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.squareup.okhttp/okhttp -->
    <dependency>
      <groupId>com.squareup.okhttp</groupId>
      <artifactId>okhttp</artifactId>
      <version>2.7.5</version>
    </dependency>

    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.4</version>
    </dependency>

  </dependencies>

  <build>
    <finalName>bitfinex</finalName>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>

      <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.2</version>
        <configuration>
          <url>http://zzuummaa.sytes.net:8070/manager/text</url>
          <server>MyAmazingServer</server>
          <path>/bitfinex</path>
        </configuration>
      </plugin>

    </plugins>
  </build>
</project>