字符串和字节数组连接(String and byte array concatenation)

字符串和字节数组连接(String and byte array concatenation)

我有一个字符串，我必须与字节数组连接，所以我尝试了这个

String msg = "msg to show"; byte[] msgByte = new byte[msg.length()]; try { msgByte = msg.getBytes("UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } byte[] command = {2,5,1,5} byte[] c = new byte[msgByte.length + command.length]; System.arraycopy(command, 0, c, 0, command.length); System.arraycopy(msjByte, 0, c, command.length, msjByte.length); for(Byte bt:c) System.out.println(bt+"");

这是输出： 2 5 1 5 109 115 103 32 ... 但我正在寻找的结果就是这个 2 5 1 5 msg ...

我需要它在一个阵列中，因为它被用作蓝牙打印机的命令。

有没有办法，有什么建议吗？

提前致谢！ :)

I have a String that I have to concatenate with an byte array, so I tried this

String msg = "msg to show"; byte[] msgByte = new byte[msg.length()]; try { msgByte = msg.getBytes("UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } byte[] command = {2,5,1,5} byte[] c = new byte[msgByte.length + command.length]; System.arraycopy(command, 0, c, 0, command.length); System.arraycopy(msjByte, 0, c, command.length, msjByte.length); for(Byte bt:c) System.out.println(bt+"");

This is the output: 2 5 1 5 109 115 103 32 ... but the result that I'm looking for is this 2 5 1 5 m s g ...

I need it in one array cause it's used as a command for a bluetooth printer.

Is there a way, any suggestions?

Thanks in advance! :)

最满意答案

你不能有一个包含'2 5 1 5 ms g'的字节数组。 从文档 ：

字节数据类型是8位带符号的二进制补码整数。 它的最小值为-128，最大值为127（含）。

我无法想象你实际上想要用字符串连接未编码的字节的情况，但这里是一个返回char[]的解决方案。

public static void main(String[] args) { final String msg = "msg to show"; final byte[] command = { 2, 5, 1, 5 }; // Prints [2, 5, 1, 5, m, s, g, , t, o, , s, h, o, w] System.out.println(Arrays.toString(concat(msg, command))); } private static char[] concat(final byte[] bytes, final String str) { final StringBuilder sb = new StringBuilder(); for (byte b : bytes) { sb.append(b); } sb.append(str); return sb.toString().toCharArray(); }

You can't have a byte array containing '2 5 1 5 m s g'. From the documentation:

The byte data type is an 8-bit signed two's complement integer. It has a minimum value of -128 and a maximum value of 127 (inclusive).

I can't envisage a scenario where you would actually want to join un-encoded bytes with a string, but here's a solution that returns a char[].

public static void main(String[] args) { final String msg = "msg to show"; final byte[] command = { 2, 5, 1, 5 }; // Prints [2, 5, 1, 5, m, s, g, , t, o, , s, h, o, w] System.out.println(Arrays.toString(concat(msg, command))); } private static char[] concat(final byte[] bytes, final String str) { final StringBuilder sb = new StringBuilder(); for (byte b : bytes) { sb.append(b); } sb.append(str); return sb.toString().toCharArray(); }