Coin sender

import org.apache.http.HttpEntity;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
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.util.EntityUtils;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

import java.io.IOException;
import java.util.UUID;

/**
Maven:

 <dependencies>
 <dependency>
 <groupId>org.apache.httpcomponents</groupId>
 <artifactId>httpclient</artifactId>
 <version>4.3.4</version>
 </dependency>
 <dependency>
 <groupId>com.googlecode.json-simple</groupId>
 <artifactId>json-simple</artifactId>
 <version>1.1.1</version>
 </dependency>
 </dependencies>

conf:

rpcuser=user1
rpcpassword=pB341z
rpcallowip=192.168.0.*
rpcport=5557
listen=1
daemon=1
server=1

 */
public class CoinSender {

    public static void main(String[] args) throws Exception {
        String ip = "192.168.0.41";
        int port = 5557;
        String targetAddress = "SDid48TEECEu7kaGFtH1i3jHEoJkiGXqPk";
        String user = "user1";
        String pass = "pB341z";

        RPCClient rpcClient = new RPCClient(ip, port, user, pass);

        int total = rpcClient.getBalance().intValue();
        int amount = 5;
        for(; total > 0; total -= amount) {
            JSONObject jsonObject = rpcClient.sendCoins(targetAddress, amount);
            System.out.println(total + ": " + jsonObject);
            Thread.sleep(60000);
        }
        rpcClient.close();
    }

    public static class RPCClient {

        private final CloseableHttpClient httpclient;
        private String ip;
        private int port;

        public RPCClient(String ip, int port, String user, String pass) {
            this.ip = ip;
            this.port = port;
            BasicCredentialsProvider credentialsProvider = new BasicCredentialsProvider();
            credentialsProvider.setCredentials(new AuthScope(ip, port), //12789
                    new UsernamePasswordCredentials(user, pass));
            httpclient = HttpClientBuilder.create()
                    .setDefaultCredentialsProvider(credentialsProvider)
                    .build();
        }

        public JSONObject invokeRPC(String id, String method, Object ...params) {
            JSONObject requestJSON = new JSONObject();
            requestJSON.put("id", id);
            requestJSON.put("method", method);
            if (null != params) {
                JSONArray array = new JSONArray();
                for (Object param : params) {
                    array.add(param);
                }
                requestJSON.put("params", array);
            }
            System.out.println(requestJSON);
            JSONObject responseJSON = null;
            try {
                StringEntity myEntity = new StringEntity(requestJSON.toJSONString());
                HttpPost httppost = new HttpPost("http://" + ip + ":" + port);
                httppost.setEntity(myEntity);

                CloseableHttpResponse response = httpclient.execute(httppost);
                HttpEntity entity = response.getEntity();

                JSONParser parser = new JSONParser();
                responseJSON = (JSONObject) parser.parse(EntityUtils.toString(entity));
                response.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return responseJSON;
        }

        public void close() throws IOException {
            httpclient.close();
        }

        public Double getBalance() {
            JSONObject json = invokeRPC(UUID.randomUUID().toString(), "getbalance");
            System.out.println("DEBUG, getBalance: " + json);
            return (Double)json.get("result");
        }

        public JSONObject sendCoins(String to, float amount) {
            return invokeRPC(UUID.randomUUID().toString(), "sendtoaddress", to, amount);
        }
    }
}