以更有效的方式替换字符串中的一组子字符串？

Question

我要用String中的一组子串替换另一个子串,例如

1. "^t" 同 "\t"
2. "^=" 同 "\u2014"
3. "^+" 同 "\u2013"
4. "^s" 同 "\u00A0"
5. "^?" 同 "."
6. "^#" 同 "\\d"
7. "^$" 同 "[a-zA-Z]"

所以,我试过:

String oppip = "pippo^t^# p^+alt^shefhjkhfjkdgfkagfafdjgbcnbch^";

Map<String,String> tokens = new HashMap<String,String>();
tokens.put("^t", "\t");
tokens.put("^=", "\u2014");
tokens.put("^+", "\u2013");
tokens.put("^s", "\u00A0");
tokens.put("^?", ".");
tokens.put("^#", "\\d");
tokens.put("^$", "[a-zA-Z]");

String regexp = "^t|^=|^+|^s|^?|^#|^$";

StringBuffer sb = new StringBuffer();
Pattern p = Pattern.compile(regexp);
Matcher m = p.matcher(oppip);
while (m.find())
    m.appendReplacement(sb, tokens.get(m.group()));
m.appendTail(sb);
System.out.println(sb.toString()); 

但它不起作用.tokens.get(m.group())抛出一个例外.

知道为什么吗？

Answer 1

你不必使用HashMap.考虑使用简单数组和循环:

String oppip = "pippo^t^# p^+alt^shefhjkhfjkdgfkagfafdjgbcnbch^";

String[] searchFor =
{"^t", "^=", "^+", "^s", "^?", "^#", "^$"},
         replacement =
{"\\t", "\\u2014", "\\u2013", "\\u00A0", ".", "\\d", "[a-zA-Z]"};

for (int i = 0; i < searchFor.length; i++)
    oppip = oppip.replace(searchFor[i], replacement[i]);

// Print the result.
System.out.println(oppip);

这是一个在线代码演示.

为了完整性,您可以使用二维数组来实现类似的方法:

String oppip = "pippo^t^# p^+alt^shefhjkhfjkdgfkagfafdjgbcnbch^";

String[][] tasks =
{
    {"^t", "\\t"},
    {"^=", "\\u2014"}, 
    {"^+", "\\u2013"}, 
    {"^s", "\\u00A0"}, 
    {"^?", "."}, 
    {"^#", "\\d"}, 
    {"^$", "[a-zA-Z]"}
};

for (String[] replacement : tasks)
    oppip = oppip.replace(replacement[0], replacement[1]);

// Print the result.
System.out.println(oppip);

Answer 2

在正则表达式中,^意思是"文本开头"(或在字符类中"不"作为否定).你必须在它之前放一个反斜杠,它在java String中变成两个反斜杠.

String regexp = "\\^[t=+s?#$]";

我进一步减少了它.