java

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.lang.management.ManagementFactory;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;

import javax.servlet.GenericServlet;

public class Utils {

    public final static int DEFAULT_BUFFER_SIZE = 1024 * 4;

    public static String read(InputStream in) {
        InputStreamReader reader;
        try {
            reader = new InputStreamReader(in, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            throw new IllegalStateException(e.getMessage(), e);
        }
        return read(reader);
    }

    public static String readFromResource(String resource) throws IOException {
        InputStream in = null;
        try {
            in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
            if (in == null) {
                in = Utils.class.getResourceAsStream(resource);
            }

            if (in == null) {
                return null;
            }

            String text = Utils.read(in);
            return text;
        } finally {
            JdbcUtils.close(in);
        }
    }

    public static byte[] readByteArrayFromResource(String resource) throws IOException {
        InputStream in = null;
        try {
            in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
            if (in == null) {
                return null;
            }

            return readByteArray(in);
        } finally {
            JdbcUtils.close(in);
        }
    }

    public static byte[] readByteArray(InputStream input) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output);
        return output.toByteArray();
    }

    public static long copy(InputStream input, OutputStream output) throws IOException {
        final int EOF = -1;

        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];

        long count = 0;
        int n = 0;
        while (EOF != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    public static String read(Reader reader) {
        try {

            StringWriter writer = new StringWriter();

            char[] buffer = new char[DEFAULT_BUFFER_SIZE];
            int n = 0;
            while (-1 != (n = reader.read(buffer))) {
                writer.write(buffer, 0, n);
            }

            return writer.toString();
        } catch (IOException ex) {
            throw new IllegalStateException("read error", ex);
        }
    }

    public static String read(Reader reader, int length) {
        try {
            char[] buffer = new char[length];

            int offset = 0;
            int rest = length;
            int len;
            while ((len = reader.read(buffer, offset, rest)) != -1) {
                rest -= len;
                offset += len;

                if (rest == 0) {
                    break;
                }
            }

            return new String(buffer, 0, length - rest);
        } catch (IOException ex) {
            throw new IllegalStateException("read error", ex);
        }
    }

    public static String toString(java.util.Date date) {
        if (date == null) {
            return null;
        }
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return format.format(date);
    }

    public static String getStackTrace(Throwable ex) {
        StringWriter buf = new StringWriter();
        ex.printStackTrace(new PrintWriter(buf));

        return buf.toString();
    }

    public static String toString(StackTraceElement[] stackTrace) {
        StringBuilder buf = new StringBuilder();
        for (StackTraceElement item : stackTrace) {
            buf.append(item.toString());
            buf.append("\n");
        }
        return buf.toString();
    }

    public static Boolean getBoolean(Properties properties, String key) {
        String property = properties.getProperty(key);
        if ("true".equals(property)) {
            return Boolean.TRUE;
        } else if ("false".equals(property)) {
            return Boolean.FALSE;
        }
        return null;
    }

    public static Boolean getBoolean(GenericServlet servlet, String key) {
        String property = servlet.getInitParameter(key);
        if ("true".equals(property)) {
            return Boolean.TRUE;
        } else if ("false".equals(property)) {
            return Boolean.FALSE;
        }
        return null;
    }

    public static Integer getInteger(Properties properties, String key) {
        String property = properties.getProperty(key);

        if (property == null) {
            return null;
        }
        try {
            return Integer.parseInt(property);
        } catch (NumberFormatException ex) {
            // skip
        }
        return null;
    }

    public static Long getLong(Properties properties, String key) {
        String property = properties.getProperty(key);

        if (property == null) {
            return null;
        }
        try {
            return Long.parseLong(property);
        } catch (NumberFormatException ex) {
            // skip
        }
        return null;
    }

    public static Class<?> loadClass(String className) {
        Class<?> clazz = null;

        if (className == null) {
            return null;
        }

        ClassLoader ctxClassLoader = Thread.currentThread().getContextClassLoader();
        if (ctxClassLoader != null) {
            try {
                clazz = ctxClassLoader.loadClass(className);
            } catch (ClassNotFoundException e) {
                // skip
            }
        }

        if (clazz != null) {
            return clazz;
        }

        try {
            return Class.forName(className);
        } catch (ClassNotFoundException e) {
            return null;
        }
    }

    private static Date startTime;

    public final static Date getStartTime() {
        if (startTime == null) {
            startTime = new Date(ManagementFactory.getRuntimeMXBean().getStartTime());
        }
        return startTime;
    }

    public static long murmurhash2_64(String text) {
        final byte[] bytes = text.getBytes();
        return murmurhash2_64(bytes, bytes.length, 0xe17a1465);
    }

    /**
     * murmur hash 2.0, The murmur hash is a relatively fast hash function from http://murmurhash.googlepages.com/ for
     * platforms with efficient multiplication.
     * 
     * @author Viliam Holub
     */
    public static long murmurhash2_64(final byte[] data, int length, int seed) {
        final long m = 0xc6a4a7935bd1e995L;
        final int r = 47;

        long h = (seed & 0xffffffffl) ^ (length * m);

        int length8 = length / 8;

        for (int i = 0; i < length8; i++) {
            final int i8 = i * 8;
            long k = ((long) data[i8 + 0] & 0xff) //
                     + (((long) data[i8 + 1] & 0xff) << 8) //
                     + (((long) data[i8 + 2] & 0xff) << 16)//
                     + (((long) data[i8 + 3] & 0xff) << 24) //
                     + (((long) data[i8 + 4] & 0xff) << 32)//
                     + (((long) data[i8 + 5] & 0xff) << 40)//
                     + (((long) data[i8 + 6] & 0xff) << 48) //
                     + (((long) data[i8 + 7] & 0xff) << 56);

            k *= m;
            k ^= k >>> r;
            k *= m;

            h ^= k;
            h *= m;
        }

        switch (length % 8) {
            case 7:
                h ^= (long) (data[(length & ~7) + 6] & 0xff) << 48;
            case 6:
                h ^= (long) (data[(length & ~7) + 5] & 0xff) << 40;
            case 5:
                h ^= (long) (data[(length & ~7) + 4] & 0xff) << 32;
            case 4:
                h ^= (long) (data[(length & ~7) + 3] & 0xff) << 24;
            case 3:
                h ^= (long) (data[(length & ~7) + 2] & 0xff) << 16;
            case 2:
                h ^= (long) (data[(length & ~7) + 1] & 0xff) << 8;
            case 1:
                h ^= (long) (data[length & ~7] & 0xff);
                h *= m;
        }
        ;

        h ^= h >>> r;
        h *= m;
        h ^= h >>> r;

        return h;
    }

    public static byte[] md5Bytes(String text) {
        MessageDigest msgDigest = null;

        try {
            msgDigest = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException("System doesn't support MD5 algorithm.");
        }

        msgDigest.update(text.getBytes());

        byte[] bytes = msgDigest.digest();

        return bytes;
    }

    public static String md5(String text) {
        byte[] bytes = md5Bytes(text);
        return HexBin.encode(bytes, false);
    }

    public static void putLong(byte[] b, int off, long val) {
        b[off + 7] = (byte) (val >>> 0);
        b[off + 6] = (byte) (val >>> 8);
        b[off + 5] = (byte) (val >>> 16);
        b[off + 4] = (byte) (val >>> 24);
        b[off + 3] = (byte) (val >>> 32);
        b[off + 2] = (byte) (val >>> 40);
        b[off + 1] = (byte) (val >>> 48);
        b[off + 0] = (byte) (val >>> 56);
    }
   
}