Java字节数组到字符串到字节数组 [英] Java Byte Array to String to Byte Array

问题描述

我正在尝试理解byte []到string，byte []到byte []转换的字符串表示...我将byte []转换为要发送的字符串，然后我希望我的Web服务（写入）在python中）将数据直接回送给客户端。

I'm trying to understand a byte[] to string, string representation of byte[] to byte[] conversion... I convert my byte[] to a string to send, I then expect my web service (written in python) to echo the data straight back to the client.

当我从我的Java应用程序发送数据时......

When I send the data from my Java application...

Arrays.toString(data.toByteArray())

要发送的字节..

[B@405217f8

发送（这是Arrays.toString（）的结果，它应该是我的字节数据的字符串表示，这些数据将通过网络发送）：

Send (This is the result of Arrays.toString() which should be a string representation of my byte data, this data will be sent across the wire):

[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]

在python方面，python服务器向调用者返回一个字符串（我可以看到它与我发送给服务器的字符串相同

On the python side, the python server returns a string to the caller (which I can see is the same as the string I sent to the server

[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]

服务器应该返回这个数据到客户端，可以在其中进行验证。

The server should return this data to the client, where it can be verified.

我的客户收到的回复（作为字符串）看起来像

The response my client receives (as a string) looks like

[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]

我似乎无法弄清楚如何将收到的字符串放回
字节[]

I can't seem to figure out how to get the received string back into a byte[]

无论我怎样尝试，我最终得到的字节数组看起来如下......

Whatever I seem to try I end up getting a byte array which looks as follows...

[91, 45, 52, 55, 44, 32, 49, 44, 32, 49, 54, 44, 32, 56, 52, 44, 32, 50, 44, 32, 49, 48, 49, 44, 32, 49, 49, 48, 44, 32, 56, 51, 44, 32, 49, 49, 49, 44, 32, 49, 48, 57, 44, 32, 49, 48, 49, 44, 32, 51, 50, 44, 32, 55, 56, 44, 32, 55, 48, 44, 32, 54, 55, 44, 32, 51, 50, 44, 32, 54, 56, 44, 32, 57, 55, 44, 32, 49, 49, 54, 44, 32, 57, 55, 93]

或者我可以获得如下字节表示：

or I can get a byte representation which is as follows:

B@2a80d889

这些都与我发送的数据不同...我敢肯定我是mi真的很简单....

Both of these are different from my sent data... I'm sure Im missing something truly simple....

任何帮助？！

推荐答案

你不能只接受返回的字符串并从中构造一个字符串...它不再是 byte [] 数据类型，它已经是一个字符串;你需要解析它。例如：

You can't just take the returned string and construct a string from it... it's not a byte[] data type anymore, it's already a string; you need to parse it. For example :

String response = "[-47, 1, 16, 84, 2, 101, 110, 83, 111, 109, 101, 32, 78, 70, 67, 32, 68, 97, 116, 97]";      // response from the Python script

String[] byteValues = response.substring(1, response.length() - 1).split(",");
byte[] bytes = new byte[byteValues.length];

for (int i=0, len=bytes.length; i<len; i++) {
   bytes[i] = Byte.parseByte(byteValues[i].trim());     
}

String str = new String(bytes);

** 编辑 **

你在问题​​中得到了一个问题的提示，你说无论我怎样尝试，我最终得到的字节数组看起来如下...... [91,45 ，... ，因为 91 是 [>的字节值，所以 [91,45，... 是字符串 [ - 45,1,16，... string。

You get an hint of your problem in your question, where you say "Whatever I seem to try I end up getting a byte array which looks as follows... [91, 45, ...", because 91 is the byte value for [, so [91, 45, ... is the byte array of the string "[-45, 1, 16, ..." string.

方法 Arrays.toString（）将返回字符串指定数组的表示;意味着返回的值不再是数组。例如：

The method Arrays.toString() will return a String representation of the specified array; meaning that the returned value will not be a array anymore. For example :

byte[] b1 = new byte[] {97, 98, 99};

String s1 = Arrays.toString(b1);
String s2 = new String(b1);

System.out.println(s1);        // -> "[97, 98, 99]"
System.out.println(s2);        // -> "abc";

如您所见， s1 持有数组的字符串表示 b1 ，而 s2 包含 b1 中包含的> bytes 。

As you can see, s1 holds the string representation of the array b1, while s2 holds the string representation of the bytes contained in b1.

现在，在你的问题中，你的服务器返回一个类似的字符串到 s1 ，因此要获得数组表示，需要相反的构造方法。如果 s2.getBytes（）与 new String（b1）相反，则需要找到 Arrays.toString（b1），因此代码我粘贴在这个答案的第一个片段中。

Now, in your problem, your server returns a string similar to s1, therefore to get the array representation back, you need the opposite constructor method. If s2.getBytes() is the opposite of new String(b1), you need to find the opposite of Arrays.toString(b1), thus the code I pasted in the first snippet of this answer.

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