我不知道你说的字节字符串到底是什么意思，但这里有一些从字节到字符串的转换，反之亦然，当然官方文档上有更多

Integer intValue = 149;

对应的字节值为:

Byte byteValue = intValue.byteValue(); // this will convert the rightmost byte of the intValue to byte, because Byte is an 8 bit object and Integer is at least 16 bit, and it will give you a signed number in this case -107

从Byte变量中返回整数值:

Integer anInt = byteValue.intValue(); // This will convert the byteValue variable to a signed Integer

从字节和整数到十六进制字符串: 我是这样做的:

Integer anInt = 149
Byte aByte = anInt.byteValue();

String hexFromInt = "".format("0x%x", anInt); // This will output 0x95
String hexFromByte = "".format("0x%x", aByte); // This will output 0x95

将字节数组转换为十六进制字符串: 据我所知，没有一个简单的函数可以将某个对象的数组中的所有元素转换为另一个对象的元素，所以你必须自己做。您可以使用以下函数:

从byte[]到String:

    public static String byteArrayToHexString(byte[] byteArray){
        String hexString = "";

        for(int i = 0; i < byteArray.length; i++){
            String thisByte = "".format("%x", byteArray[i]);
            hexString += thisByte;
        }

        return hexString;
    }

从十六进制字符串到字节[]:

public static byte[] hexStringToByteArray(String hexString){
    byte[] bytes = new byte[hexString.length() / 2];

    for(int i = 0; i < hexString.length(); i += 2){
        String sub = hexString.substring(i, i + 2);
        Integer intVal = Integer.parseInt(sub, 16);
        bytes[i / 2] = intVal.byteValue();
        String hex = "".format("0x%x", bytes[i / 2]);
    }

    return bytes;
}  

现在已经太迟了，但我希望这能帮助到其他人;)

试试这个方法:

byte bv = 10;
String hexString = Integer.toHexString(bv);

处理数组(如果我没理解错的话):

byte[] bytes = {9, 10, 11, 15, 16};
StringBuffer result = new StringBuffer();
for (byte b : bytes) {
    result.append(String.format("%02X ", b));
    result.append(" "); // delimiter
}
return result.toString();

正如polygeneluants所提到的，String.format()是与Integer.toHexString()相比的正确答案(因为它以正确的方式处理负数)。

Use

Integer.toHexString((int)b);

只是添加我的两分，因为我看到许多答案使用字符数组和/或使用StringBuilder实例，并声称是快速或更快。

由于我使用ASCII表组织有一个不同的想法，代码点48-57为0-9，代码点65-70为a-f，代码点97-102为a-f，我想测试哪个想法是最快的。

因为我已经好几年没有做过类似的事情了，所以我要做一个广泛的拍摄。我在不同大小的数组中使用了10亿字节(1M, 1K, 10)，因此每个数组有1000倍1M字节，每个数组有1M倍1000字节，每个数组有100M倍10字节。

结果是1-F中的char数组胜出。使用char数组而不是StringBuilder作为输出也很容易(对象更少，不需要测试容量，在增长时不需要新数组或复制)。此外，当使用foreach (for(var b: bytes))循环时，你似乎会得到一个小的惩罚。

使用我的想法的版本大约是。每个数组1M字节时慢15%，每个数组1000字节时慢21%，每个数组10字节时慢18%。StringBuilder版本分别慢了210%、380%和310%。

这很糟糕，但也不是那么出乎意料，因为在第一级缓存中查找小数组胜过if和add... .(一个缓存访问+偏移量计算vs.一个if，一个跳转，一个add ->不确定跳转thou)。

我的版本:

public static String bytesToHex(byte [] bytes) {
    
    char [] result = new char [bytes.length * 2];
    
    for(int index = 0; index < bytes.length; index++) {
        int v = bytes[index]; 

        int upper = (v >>> 4) & 0xF;
        result[index * 2] = (char)(upper + (upper < 10 ? 48 : 65 - 10));
        
        int lower = v & 0xF;
        result[index * 2 + 1] = (char)(lower + (lower < 10 ? 48 : 65 - 10));
    }
    
    return new String(result);
}

PS:是的，我做了多次测试，每次都做了最好的测试，做了热身，也做了100亿字符的测试，以确保相同的图片... .

你可以使用Bouncy Castle Provider库中的方法:

org.bouncycastle.util.encoders.Hex.toHexString(byteArray);

Bouncy Castle Crypto包是一个Java实现 加密算法。这个jar包含JCE提供程序和 用于JDK 1.5的Bouncy Castle Cryptography API的轻量级API JDK 1.8。

Maven的依赖:

<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.60</version>
</dependency>

或来自Apache Commons Codec:

org.apache.commons.codec.binary.Hex.encodeHexString(byteArray);

Apache Commons Codec包包含简单的编码器和解码器 用于各种格式，如Base64和十六进制。除了 这些编码器和解码器被广泛使用，编解码器包也有 维护语音编码实用程序的集合。

Maven的依赖:

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>1.11</version>
</dependency>

这是你的快速方法:

    private static final String[] hexes = new String[]{
        "00","01","02","03","04","05","06","07","08","09","0A","0B","0C","0D","0E","0F",
        "10","11","12","13","14","15","16","17","18","19","1A","1B","1C","1D","1E","1F",
        "20","21","22","23","24","25","26","27","28","29","2A","2B","2C","2D","2E","2F",
        "30","31","32","33","34","35","36","37","38","39","3A","3B","3C","3D","3E","3F",
        "40","41","42","43","44","45","46","47","48","49","4A","4B","4C","4D","4E","4F",
        "50","51","52","53","54","55","56","57","58","59","5A","5B","5C","5D","5E","5F",
        "60","61","62","63","64","65","66","67","68","69","6A","6B","6C","6D","6E","6F",
        "70","71","72","73","74","75","76","77","78","79","7A","7B","7C","7D","7E","7F",
        "80","81","82","83","84","85","86","87","88","89","8A","8B","8C","8D","8E","8F",
        "90","91","92","93","94","95","96","97","98","99","9A","9B","9C","9D","9E","9F",
        "A0","A1","A2","A3","A4","A5","A6","A7","A8","A9","AA","AB","AC","AD","AE","AF",
        "B0","B1","B2","B3","B4","B5","B6","B7","B8","B9","BA","BB","BC","BD","BE","BF",
        "C0","C1","C2","C3","C4","C5","C6","C7","C8","C9","CA","CB","CC","CD","CE","CF",
        "D0","D1","D2","D3","D4","D5","D6","D7","D8","D9","DA","DB","DC","DD","DE","DF",
        "E0","E1","E2","E3","E4","E5","E6","E7","E8","E9","EA","EB","EC","ED","EE","EF",
        "F0","F1","F2","F3","F4","F5","F6","F7","F8","F9","FA","FB","FC","FD","FE","FF"
    };

    public static String byteToHex(byte b) {
        return hexes[b&0xFF];
    }