commons-codec中常用方法

一、Base64編碼和解碼

import org.apache.commons.codec.EncoderException;
import org.apache.commons.codec.binary.Base64;
public class TestBase64 {
    public static void main(String[] args) throws EncoderException, UnsupportedEncodingException {
        Base64 base64 = new Base64();
        String str = "AAaaa我";
        String result = base64.encodeToString(str.getBytes("UTF-8"));//編碼
        System.out.println(result);
        byte[] decode = base64.decode(result.getBytes());//解碼
        System.out.println(new String(decode));
    }
}

二、Hex編碼和解碼

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;
public class TestHex {
    public static void main(String[] args) throws DecoderException, UnsupportedEncodingException {
        String str = "test";
        /**編碼*/
        String hexString = Hex.encodeHexString(str.getBytes("UTF-8"));//直接一步到位
        System.out.println(hexString);
        char[] encodeHex = Hex.encodeHex(str.getBytes(), true);//先轉換成char數組，第二個參數意思是是否全部轉換成小寫
        System.out.println(new String(encodeHex));
        /**解碼*/
        byte[] decodeHex = Hex.decodeHex(encodeHex);//char數組型的
        System.out.println(new String(decodeHex));
        byte[] decodeHex2 = Hex.decodeHex(hexString.toCharArray());//字符串類型的，該方法要求傳入的是char[]
        System.out.println(new String(decodeHex2));
    }
}

三、MD5加密（MD5是不可逆算法，只能加密）

import java.io.UnsupportedEncodingException;
import org.apache.commons.codec.digest.DigestUtils;
public class TestMD5 {
    public static void main(String[] args) throws UnsupportedEncodingException {
        String str = "test";
        String md5 = DigestUtils.md5Hex(str.getBytes("UTF-8"));
        System.out.println(md5);
    }
}

四、SHA加密

import java.io.UnsupportedEncodingException;
import org.apache.commons.codec.digest.DigestUtils;
public class TestSHA {
    public static void main(String[] args) throws UnsupportedEncodingException {
        String str = "test中國";
        String sha1Hex = DigestUtils.sha1Hex(str.getBytes("UTF-8"));
        System.out.println(sha1Hex);
    }
}

五、URLCodec

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.EncoderException;
import org.apache.commons.codec.net.URLCodec;
public class TestURLCodec {
    public static void main(String[] args) throws EncoderException, DecoderException {
        String url = "http://baidu.com?name=你好";
        URLCodec codec = new URLCodec();
        String encode = codec.encode(url);
        System.out.println(encode);
        String decode = codec.decode(encode);
        System.out.println(decode);
    }
}

除了這些還有很多算法比如HMAC等，大家可以根據需要選取