nl.ordina.bag.etl.mail.handler.HttpClient.java Source code

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Here is the source code for nl.ordina.bag.etl.mail.handler.HttpClient.java

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/**
 * Copyright 2013 Ordina
 *
 * 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 nl.ordina.bag.etl.mail.handler;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.util.UUID;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.net.ssl.HttpsURLConnection;

import org.apache.commons.io.IOUtils;

public class HttpClient {
    private SSLFactoryManager sslFactoryManager = new SSLFactoryManager();
    private Pattern filePattern;

    public HttpClient() throws NoSuchAlgorithmException, KeyManagementException {
        filePattern = Pattern.compile("^attachment;\\s*filename=\"(.*)\"$");
    }

    public File downloadFile(String uri) throws IOException {
        HttpURLConnection connection = null;
        try {
            connection = getConnection(uri);
            connection.connect();
            return handleResponse(connection);
        } finally {
            if (connection != null)
                connection.disconnect();
        }
    }

    private HttpURLConnection getConnection(String uri) throws IOException {
        URL url = new URL(uri);
        HttpURLConnection result = (HttpURLConnection) url.openConnection();
        if (result instanceof HttpsURLConnection) {
            ((HttpsURLConnection) result).setSSLSocketFactory(sslFactoryManager.getSslSocketFactory());
            ((HttpsURLConnection) result).setHostnameVerifier(sslFactoryManager.getHostnameVerifier());
        }
        result.setRequestMethod("GET");
        result.setDoOutput(true);
        return result;
    }

    private File handleResponse(HttpURLConnection connection) throws IOException {
        if (connection.getResponseCode() == 200) {
            String filename = getFilename(connection);
            return writeToFile(filename, connection.getInputStream());
        } else
            throw new IOException("Could not read file from " + connection.getURL().toString()
                    + ". Received response code " + connection.getResponseCode());
    }

    private String getFilename(HttpURLConnection connection) {
        String s = connection.getHeaderField("Content-Disposition");
        Matcher matcher = filePattern.matcher(s);
        return matcher.find() ? matcher.group(1) : UUID.randomUUID().toString();
    }

    private File writeToFile(String filename, InputStream inputStream) throws IOException {
        File result = File.createTempFile(filename, null);
        result.deleteOnExit();
        try (FileOutputStream out = new FileOutputStream(result)) {
            IOUtils.copy(inputStream, out);
        }
        return result;
    }

}