1）我得到xml作为java字符串与其中（我现在没有访问接口，但我可能得到xml作为一个java串）。我可以用replaceAll（£，）去掉这个字符吗？

我假设你的意思是想要摆脱非 ASCII 字符，因为你在谈论一个遗产方面。您可以使用以下正则表达式来摆脱可打印ASCII范围之外的任何内容：

  string = string.replaceAll（[^ \\\x20-\\\x7e]，）; 
 

2）我将xml作为字节数组 - 如何处理在这种情况下，这个操作是安全的吗？

你需要包装 byte [] 在 ByteArrayInputStream ，以便您可以使用 InputStreamReader ，其中您指定编码，然后使用 BufferedReader 逐行阅读。

例如

  BufferedReader reader = null; 
 try {
 reader = new BufferedReader（new InputStreamReader（new ByteArrayInputStream（bytes），UTF-8））; 
 for（String line;（line = reader.readLine（））！= null;）{
 line = line.replaceAll（[^ \\\x20-\\x7e] ，）; 
 // ... 
} 
 // ... 
 

I have to handle this scenario in Java:

I'm getting a request in XML form from a client with declared encoding=utf-8. Unfortunately it may contain not utf-8 characters and there is a requirement to remove these characters from the xml on my side (legacy).

Let's consider an example where this invalid XML contains £ (pound).

1) I get xml as java String with £ in it (I don't have access to interface right now, but I probably get xml as a java String). Can I use replaceAll(£, "") to get rid of this character? Any potential issues?

2) I get xml as an array of bytes - how to handle this operation safely in that case?

1) I get xml as java String with £ in it (I don't have access to interface right now, but I probably get xml as a java String). Can I use replaceAll(£, "") to get rid of this character?

I am assuming that you rather mean that you want to get rid of non-ASCII characters, because you're talking about a "legacy" side. You can get rid of anything outside the printable ASCII range using the following regex:

string = string.replaceAll("[^\\x20-\\x7e]", "");

2) I get xml as an array of bytes - how to handle this operation safely in that case?

You need to wrap the byte[] in an ByteArrayInputStream, so that you can read them in an UTF-8 encoded character stream using InputStreamReader wherein you specify the encoding and then use a BufferedReader to read it line by line.

E.g.

BufferedReader reader = null;
try {
    reader = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(bytes), "UTF-8"));
    for (String line; (line = reader.readLine()) != null;) {
        line = line.replaceAll("[^\\x20-\\x7e]", "");
        // ...
    }
    // ...