de.perdian.apps.dashboard.support.clients.JsonClient.java Source code

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Here is the source code for de.perdian.apps.dashboard.support.clients.JsonClient.java

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/*
 * Dashboard
 * Copyright 2014 Christian Robert
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package de.perdian.apps.dashboard.support.clients;

import java.util.Map;
import java.util.Properties;

import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.auth.BasicScheme;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.protocol.BasicHttpContext;
import org.codehaus.jackson.JsonNode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import de.perdian.apps.dashboard.DashboardException;

/**
 * Abstract implementation of a client that establishes a connection to a remote
 * system and is able to retrieve JSON data from that remote system.
 *
 * @author Christian Robert
 */

public class JsonClient implements AutoCloseable {

    private static final Logger log = LoggerFactory.getLogger(JsonClient.class);

    private String username = null;
    private String password = null;
    private Properties defaultHeaders = null;
    private CloseableHttpClient httpClient = null;

    public JsonClient(String username, String password) {
        this(username, password, 1000 * 10);
    }

    public JsonClient(String username, String password, int timeout) {
        RequestConfig.Builder requestBuilder = RequestConfig.custom();
        requestBuilder.setConnectTimeout(timeout);
        requestBuilder.setSocketTimeout(timeout);
        HttpClientBuilder clientBuilder = HttpClientBuilder.create();
        clientBuilder.setDefaultRequestConfig(requestBuilder.build());
        this.setHttpClient(clientBuilder.build());
        this.setDefaultHeaders(new Properties());
        this.setUsername(username);
        this.setPassword(password);
    }

    @Override
    @SuppressWarnings("resource")
    public void close() {
        CloseableHttpClient currentClient = this.getHttpClient();
        if (currentClient != null) {
            try {
                currentClient.close();
            } catch (Exception e) {
                log.trace("Cannot close HttpClient", e);
            }
        }
    }

    @Override
    public String toString() {
        StringBuilder result = new StringBuilder();
        result.append(this.getClass().getSimpleName());
        result.append("[httpClient=").append(this.getHttpClient());
        return result.append("]").toString();
    }

    /**
     * Executes the given job and return the response
     *
     * @param requestUri
     *     the URI to which the request should be sent
     * @return
     *     the JSON result
     */
    public JsonNode sendRequest(CharSequence requestUri) {
        try {

            HttpGet httpGet = new HttpGet(requestUri.toString());
            if (this.getUsername() != null && this.getPassword() != null) {
                httpGet.addHeader(new BasicScheme().authenticate(
                        new UsernamePasswordCredentials(this.getUsername(), this.getPassword()), httpGet,
                        new BasicHttpContext()));
            }
            for (Map.Entry<Object, Object> defaultHeaderEntry : this.getDefaultHeaders().entrySet()) {
                httpGet.addHeader((String) defaultHeaderEntry.getKey(), (String) defaultHeaderEntry.getValue());
            }

            String httpResponseString = this.getHttpClient().execute(httpGet, new BasicResponseHandler());
            return JsonUtil.fromJsonString(httpResponseString);

        } catch (Exception e) {
            StringBuilder errorMessage = new StringBuilder();
            errorMessage.append("Cannot send HTTP request [").append(requestUri);
            errorMessage.append("] using client [").append(this).append("]");
            log.debug(errorMessage.toString(), e);
            throw new DashboardException(errorMessage.toString(), e);
        }
    }

    // -------------------------------------------------------------------------
    // --- Property access methods ---------------------------------------------
    // -------------------------------------------------------------------------

    private CloseableHttpClient getHttpClient() {
        return this.httpClient;
    }

    private void setHttpClient(CloseableHttpClient httpClient) {
        this.httpClient = httpClient;
    }

    public String getUsername() {
        return this.username;
    }

    private void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return this.password;
    }

    private void setPassword(String password) {
        this.password = password;
    }

    public Properties getDefaultHeaders() {
        return this.defaultHeaders;
    }

    public void setDefaultHeaders(Properties defaultHeaders) {
        this.defaultHeaders = defaultHeaders;
    }

}