Java实践篇-使用Md5/Sha1/base64

1. 生成MD5

1.1 使用 Spring自带的DigestUtils

包: org.springframework.util.DigestUtils

package com.hui.javalearn;

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.util.DigestUtils;

@SpringBootTest
class JavaLearnApplicationTests {
    @Test
    void md5(){
        String token = "123";
        String s = DigestUtils.md5DigestAsHex(token.getBytes()).toUpperCase();
        System.out.println(s);
    }
}

1.2 使用JDK自带MessageDigest

包: java.security.MessageDigest

package com.hui.javalearn;

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

@SpringBootTest
class JavaLearnApplicationTests {

    @Test
    void md52() throws NoSuchAlgorithmException {
        String token = "123";
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] digest = md5.digest(token.getBytes());
        String s = new BigInteger(1,digest).toString(16);
        System.out.println("md52=>"+s);
    }
}

1.3 使用Apache开源组织提供commons-codec

包: org.apache.commons.codec.digest.DigestUtils

package com.hui.javalearn;

import org.apache.commons.codec.digest.DigestUtils;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;


@SpringBootTest
public class TestDigest {

    @Test
    void testMd5ByCommonCodec() {
        String s = "123";
        String s1 = DigestUtils.md5Hex(s);
        System.out.println(s1);
    }
}

2. 生成Sha1

2.1 使用Apache开源组织提供commons-codec

包: org.apache.commons.codec.digest.DigestUtils

String str = "abc";
String s1 = DigestUtils.sha1Hex(str);

2.2 使用Jdk 生成: 方式1

包: java.security.MessageDigest

/**
* 使用自带JDK生成SHA1
* @param str
* @return
*/
public String testSha1ByJDK(String str) {
    if (str == null || str.length() == 0) {
        return null;
    }
    try {
        char[] hexDigits = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'a', 'b', 'c', 'd', 'e', 'f'};
        MessageDigest sha1 = MessageDigest.getInstance("SHA1");
        sha1.update(str.getBytes("UTF-8"));
        byte[] digest = sha1.digest();
        int length = digest.length;
        char[] buf = new char[length * 2];
        int k = 0;
        for (int i = 0; i < length; i++) {
            byte b = digest[i];
            buf[k++] = hexDigits[b >>> 4 & 0xf];
            buf[k++] = hexDigits[b & 0xf];
        }
        return new String(buf);
    } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
        e.printStackTrace();
        return null;
    }
}

2.3 使用Jdk 生成: 方式2

/**
 * 使用自带JDK生成SHA1
 * @param str
 * @return
 */
public String testSha1ByJDK2(String str){
    MessageDigest sha1 = null;
    try {
        sha1 = MessageDigest.getInstance("SHA1");
        sha1.update(str.getBytes("UTF-8"));
        byte[] digest = sha1.digest();
        // 转换为十六进制
        return String.format("%040x", new BigInteger(1, digest));
    } catch (NoSuchAlgorithmException | UnsupportedEncodingException e ) {
        e.printStackTrace();
        return null;
    }
}

3.Base64

包: java.util.Base64

// 编码
String str = "abc";
String encodeStr = Base64.getEncoder().encodeToString(str.getBytes());
// 解码
byte[] decode = Base64.getDecoder().decode(encodeStr.getBytes());
String decodeStr = new String(decode);