DigestUtils加密工具类

DigestUtils是一个加密算法工具类，在package org.apache.commons.codec.digest;这个包下。

如常用的md2 md5 sha sha1 sha256 sha384 sha512 加密算法

源码：

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.apache.commons.codec.digest;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.binary.StringUtils;

public class DigestUtils {
    private static final int STREAM_BUFFER_LENGTH = 1024;
    private final MessageDigest messageDigest;

    public static byte[] digest(MessageDigest messageDigest, byte[] data) {
        return messageDigest.digest(data);
    }

    public static byte[] digest(MessageDigest messageDigest, ByteBuffer data) {
        messageDigest.update(data);
        return messageDigest.digest();
    }

    public static byte[] digest(MessageDigest messageDigest, File data) throws IOException {
        return updateDigest(messageDigest, data).digest();
    }

    public static byte[] digest(MessageDigest messageDigest, InputStream data) throws IOException {
        return updateDigest(messageDigest, data).digest();
    }

    public static MessageDigest getDigest(String algorithm) {
        try {
            return MessageDigest.getInstance(algorithm);
        } catch (NoSuchAlgorithmException var2) {
            throw new IllegalArgumentException(var2);
        }
    }

    public static MessageDigest getDigest(String algorithm, MessageDigest defaultMessageDigest) {
        try {
            return MessageDigest.getInstance(algorithm);
        } catch (Exception var3) {
            return defaultMessageDigest;
        }
    }

    public static MessageDigest getMd2Digest() {
        return getDigest("MD2");
    }

    public static MessageDigest getMd5Digest() {
        return getDigest("MD5");
    }

    public static MessageDigest getSha1Digest() {
        return getDigest("SHA-1");
    }

    public static MessageDigest getSha256Digest() {
        return getDigest("SHA-256");
    }

    public static MessageDigest getSha384Digest() {
        return getDigest("SHA-384");
    }

    public static MessageDigest getSha512Digest() {
        return getDigest("SHA-512");
    }

    /** @deprecated */
    @Deprecated
    public static MessageDigest getShaDigest() {
        return getSha1Digest();
    }

    public static byte[] md2(byte[] data) {
        return getMd2Digest().digest(data);
    }

    public static byte[] md2(InputStream data) throws IOException {
        return digest(getMd2Digest(), data);
    }

    public static byte[] md2(String data) {
        return md2(StringUtils.getBytesUtf8(data));
    }

    public static String md2Hex(byte[] data) {
        return Hex.encodeHexString(md2(data));
    }

    public static String md2Hex(InputStream data) throws IOException {
        return Hex.encodeHexString(md2(data));
    }

    public static String md2Hex(String data) {
        return Hex.encodeHexString(md2(data));
    }

    public static byte[] md5(byte[] data) {
        return getMd5Digest().digest(data);
    }

    public static byte[] md5(InputStream data) throws IOException {
        return digest(getMd5Digest(), data);
    }

    public static byte[] md5(String data) {
        return md5(StringUtils.getBytesUtf8(data));
    }

    public static String md5Hex(byte[] data) {
        return Hex.encodeHexString(md5(data));
    }

    public static String md5Hex(InputStream data) throws IOException {
        return Hex.encodeHexString(md5(data));
    }

    public static String md5Hex(String data) {
        return Hex.encodeHexString(md5(data));
    }

    /** @deprecated */
    @Deprecated
    public static byte[] sha(byte[] data) {
        return sha1(data);
    }

    /** @deprecated */
    @Deprecated
    public static byte[] sha(InputStream data) throws IOException {
        return sha1(data);
    }

    /** @deprecated */
    @Deprecated
    public static byte[] sha(String data) {
        return sha1(data);
    }

    public static byte[] sha1(byte[] data) {
        return getSha1Digest().digest(data);
    }

    public static byte[] sha1(InputStream data) throws IOException {
        return digest(getSha1Digest(), data);
    }

    public static byte[] sha1(String data) {
        return sha1(StringUtils.getBytesUtf8(data));
    }

    public static String sha1Hex(byte[] data) {
        return Hex.encodeHexString(sha1(data));
    }

    public static String sha1Hex(InputStream data) throws IOException {
        return Hex.encodeHexString(sha1(data));
    }

    public static String sha1Hex(String data) {
        return Hex.encodeHexString(sha1(data));
    }

    public static byte[] sha256(byte[] data) {
        return getSha256Digest().digest(data);
    }

    public static byte[] sha256(InputStream data) throws IOException {
        return digest(getSha256Digest(), data);
    }

    public static byte[] sha256(String data) {
        return sha256(StringUtils.getBytesUtf8(data));
    }

    public static String sha256Hex(byte[] data) {
        return Hex.encodeHexString(sha256(data));
    }

    public static String sha256Hex(InputStream data) throws IOException {
        return Hex.encodeHexString(sha256(data));
    }

    public static String sha256Hex(String data) {
        return Hex.encodeHexString(sha256(data));
    }

    public static byte[] sha384(byte[] data) {
        return getSha384Digest().digest(data);
    }

    public static byte[] sha384(InputStream data) throws IOException {
        return digest(getSha384Digest(), data);
    }

    public static byte[] sha384(String data) {
        return sha384(StringUtils.getBytesUtf8(data));
    }

    public static String sha384Hex(byte[] data) {
        return Hex.encodeHexString(sha384(data));
    }

    public static String sha384Hex(InputStream data) throws IOException {
        return Hex.encodeHexString(sha384(data));
    }

    public static String sha384Hex(String data) {
        return Hex.encodeHexString(sha384(data));
    }

    public static byte[] sha512(byte[] data) {
        return getSha512Digest().digest(data);
    }

    public static byte[] sha512(InputStream data) throws IOException {
        return digest(getSha512Digest(), data);
    }

    public static byte[] sha512(String data) {
        return sha512(StringUtils.getBytesUtf8(data));
    }

    public static String sha512Hex(byte[] data) {
        return Hex.encodeHexString(sha512(data));
    }

    public static String sha512Hex(InputStream data) throws IOException {
        return Hex.encodeHexString(sha512(data));
    }

    public static String sha512Hex(String data) {
        return Hex.encodeHexString(sha512(data));
    }

    /** @deprecated */
    @Deprecated
    public static String shaHex(byte[] data) {
        return sha1Hex(data);
    }

    /** @deprecated */
    @Deprecated
    public static String shaHex(InputStream data) throws IOException {
        return sha1Hex(data);
    }

    /** @deprecated */
    @Deprecated
    public static String shaHex(String data) {
        return sha1Hex(data);
    }

    public static MessageDigest updateDigest(MessageDigest messageDigest, byte[] valueToDigest) {
        messageDigest.update(valueToDigest);
        return messageDigest;
    }

    public static MessageDigest updateDigest(MessageDigest messageDigest, ByteBuffer valueToDigest) {
        messageDigest.update(valueToDigest);
        return messageDigest;
    }

    public static MessageDigest updateDigest(MessageDigest digest, File data) throws IOException {
        BufferedInputStream stream = new BufferedInputStream(new FileInputStream(data));

        MessageDigest var3;
        try {
            var3 = updateDigest(digest, (InputStream)stream);
        } finally {
            stream.close();
        }

        return var3;
    }

    public static MessageDigest updateDigest(MessageDigest digest, InputStream data) throws IOException {
        byte[] buffer = new byte[1024];

        for(int read = data.read(buffer, 0, 1024); read > -1; read = data.read(buffer, 0, 1024)) {
            digest.update(buffer, 0, read);
        }

        return digest;
    }

    public static MessageDigest updateDigest(MessageDigest messageDigest, String valueToDigest) {
        messageDigest.update(StringUtils.getBytesUtf8(valueToDigest));
        return messageDigest;
    }

    public static boolean isAvailable(String messageDigestAlgorithm) {
        return getDigest(messageDigestAlgorithm, (MessageDigest)null) != null;
    }

    /** @deprecated */
    @Deprecated
    public DigestUtils() {
        this.messageDigest = null;
    }

    public DigestUtils(MessageDigest digest) {
        this.messageDigest = digest;
    }

    public DigestUtils(String name) {
        this(getDigest(name));
    }

    public MessageDigest getMessageDigest() {
        return this.messageDigest;
    }

    public byte[] digest(byte[] data) {
        return updateDigest(this.messageDigest, data).digest();
    }

    public byte[] digest(String data) {
        return updateDigest(this.messageDigest, data).digest();
    }

    public byte[] digest(ByteBuffer data) {
        return updateDigest(this.messageDigest, data).digest();
    }

    public byte[] digest(File data) throws IOException {
        return updateDigest(this.messageDigest, data).digest();
    }

    public byte[] digest(InputStream data) throws IOException {
        return updateDigest(this.messageDigest, data).digest();
    }

    public String digestAsHex(byte[] data) {
        return Hex.encodeHexString(this.digest(data));
    }

    public String digestAsHex(String data) {
        return Hex.encodeHexString(this.digest(data));
    }

    public String digestAsHex(ByteBuffer data) {
        return Hex.encodeHexString(this.digest(data));
    }

    public String digestAsHex(File data) throws IOException {
        return Hex.encodeHexString(this.digest(data));
    }

    public String digestAsHex(InputStream data) throws IOException {
        return Hex.encodeHexString(this.digest(data));
    }
}