org.ndogen.util.FileUtils.java Source code

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Here is the source code for org.ndogen.util.FileUtils.java

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/**
 *  Copyright 2011 Oliver Buchtala
 *
 *   This file is part of ndogen.
 *
 *  ndogen is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  ndogen is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with ndogen.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.ndogen.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public class FileUtils {

    public static String readFile(String file) throws IOException {
        int len = (int) (new File(file)).length();
        FileInputStream fis = new FileInputStream(file);
        byte buf[] = new byte[len];
        fis.read(buf);
        fis.close();

        return new String(buf);
    }

    public static InputStream getResource(String res) throws FileNotFoundException {
        URL tokensResource = ClassLoader.getSystemClassLoader().getResource(res);
        FileInputStream is;
        try {
            is = new FileInputStream(new File(tokensResource.toURI()));
            return is;
        } catch (URISyntaxException e) {
            throw new RuntimeException(e);
        }
    }

    public static String getFileHash(File file) throws IOException {
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
        InputStream is = new FileInputStream(file);
        byte[] buf = new byte[1024];
        try {
            is = new DigestInputStream(is, md);
            // read stream to EOF as normal...
            while (is.read(buf) > 0)
                ;
        } finally {
            is.close();
        }
        byte[] digest = md.digest();
        return new String(digest);
    }

    public static String getMD5(String s) throws NoSuchAlgorithmException {
        byte[] bytes = s.getBytes();
        MessageDigest algorithm = MessageDigest.getInstance("MD5");
        algorithm.reset();
        algorithm.update(bytes);
        byte messageDigest[] = algorithm.digest();

        StringBuffer hexString = new StringBuffer();
        for (int i = 0; i < messageDigest.length; i++) {
            hexString.append(Integer.toHexString(0xFF & messageDigest[i]));
        }
        return hexString.toString();
    }

    public static String objectToJson(Object o) {
        GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder.excludeFieldsWithoutExposeAnnotation();
        gsonBuilder.setDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
        Gson gson = gsonBuilder.create();
        String json = gson.toJson(o);

        return json;
    }
}