org.codehaus.mojo.license.utils.HttpRequester.java Source code

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Here is the source code for org.codehaus.mojo.license.utils.HttpRequester.java

Source

package org.codehaus.mojo.license.utils;

import java.io.BufferedReader;
import java.io.CharArrayReader;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.maven.plugin.MojoExecutionException;

/**
 * project: license-maven-plugin <br>
 * author: Pascal Knueppel <br>
 * created at: 25.01.2018 - 09:27 <br>
 * <br>
 * this class should be used to send HTTP requests to some destinations and return the content from these
 * resources.
 */
public class HttpRequester {

    /**
     * checks if the input in the {@link org.codehaus.mojo.license.AbstractAddThirdPartyMojo#includedLicenses}
     * is a URL value
     *
     * @param data the license string or a URL
     * @return true if URL, false else
     */
    public static boolean isStringUrl(String data) {
        if (StringUtils.isBlank(data)) {
            return false;
        }
        try {
            new URL(data);
            return true;
        } catch (MalformedURLException e) {
            return false;
        }
    }

    /**
     * this method will send a simple GET-request to the given destination and will return the result as a
     * string
     * 
     * @param url the resource destination that is expected to contain pure text
     * @return the string representation of the resource at the given URL
     */
    public static String getFromUrl(String url) throws MojoExecutionException {
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        HttpGet get = new HttpGet(url);
        CloseableHttpResponse response = null;

        String result = null;
        try {
            response = httpClient.execute(get);
            result = IOUtils.toString(response.getEntity().getContent(), Charset.forName("UTF-8"));
        } catch (ClientProtocolException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        } catch (IOException e) {
            throw new MojoExecutionException(e.getMessage(), e);
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                    throw new MojoExecutionException(e.getMessage(), e);
                }
            }
        }
        return result;
    }

    /**
     * will download a external resource and read the content of the file that will then be translated into a
     * new list. <br>
     * Lines starting with the character '#' will be omitted from the list <br>
     * <br>
     * <b>NOTE:</b><br>
     * certificate checking for this request will be disabled because some resources might be present on some
     * local servers in the internal network that do not use a safe connection
     *
     * @param url the URL to the external resource
     * @return a new list with all license entries from the remote resource
     */
    public static List<String> downloadList(String url) throws MojoExecutionException {
        List<String> list = new ArrayList<>();
        BufferedReader bufferedReader = null;
        try {
            bufferedReader = new BufferedReader(new CharArrayReader(getFromUrl(url).toCharArray()));
            String line;
            while ((line = bufferedReader.readLine()) != null) {
                if (StringUtils.isNotBlank(line)) {
                    if (!StringUtils.startsWith(line, "#") && !list.contains(line)) {
                        list.add(line);
                    }
                }
            }
        } catch (IOException e) {
            throw new MojoExecutionException("could not open connection to URL: " + url, e);
        } finally {
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException e) {
                    throw new MojoExecutionException(e.getMessage(), e);
                }
            }
        }
        return list;
    }
}