String.replace（）并非取代所有的发生

Question

我有一个非常长的字符串，看起来类似于此。

355,356,357,358,359,360,361,382,363,364,365,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,368,369,313,370,371,372,373,374,375,376,377,378,379,380,381,382,382,382,382,382,382,383,384,385,380,381,382,382,382,382,382,386,387,388,389,380,381,382,382,382,382,382,382,390,391,380,381,382,382,382,382,382,392,393,394,395,396,397,398,399,.... 

当我尝试使用下面的代码从字符串中删除数字382。

String str = "355,356,357,358,359,360,361,382,363,364,365,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,368,369,313,370,371,372,373,374,375,376,377,378,379,380,381,382,382,382,382,382,382,383,384,385,380,381,382,382,382,382,382,386,387,388,389,380,381,382,382,382,382,382,382,390,391,380,381,382,382,382,382,382,392,393,394,395,396,397,398,399,...." 
str = str.replace(",382,", ","); 

但似乎并非所有的事件都被取代。最初发生3000次以上的字符串在更换后仍有约630次出现。

String.replace（）的能力有限吗？如果是这样，是否有可能实现我所需要的方式？

Answer 1

需要更换后面的逗号以及（如果存在的话，它不会如果列表中最后一个）：

str = str.replaceAll("\\b382,?", ""); 

注\b字的边界，以防止匹配"-,1382,-"。

以上将转换：

382,111,382,1382,222,382 

到：

111,1382,222 

Answer 2

我认为这个问题是382后和之前，你的第一个参数replace()，特别是逗号（，）如果您有“382382383”，你将只匹配内“382”，并留下最初的一个落后。尝试：

str.replace("382,", ""); 

虽然这将无法匹配“382”在最后，因为它后面没有逗号。

完整的解决方案可能涉及二方法调用这样的：

str = str.replace("382", ""); // Remove all instances of 382 
str.replaceAll(",,+", ","); // Compress all duplicates, triplicates, etc. of commas 

这结合了两种方法：

str.replaceAll("382,?", ""); // Remove 382 and an optional comma after it. 

注：无论是过去的两种方法会留下拖逗号，如果382是在结束。

Answer 3

试试这个

str = str.replaceAll(",382,", ","); 

Answer 4

首先，去掉前面的逗号在匹配的字符串。然后，通过使用java正则表达式用逗号替换逗号来删除重复的逗号。

String input = "355,356,357,358,359,360,361,382,363,364,365,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,360,361,363,366,368,369,313,370,371,372,373,374,375,376,377,378,379,380,381,382,382,382,382,382,382,383,384,385,380,381,382,382,382,382,382,386,387,388,389,380,381,382,382,382,382,382,382,390,391,380,381,382,382,382,382,382,392,393,394,395,396,397,398,399"; 
    String result = input.replace("382,", ","); // remove the preceding comma 
    String result2 = result.replaceAll("[,]+", ","); // replace duplicate commas 

    System.out.println(result2); 

Answer 5

戴维已经说了，问题是，你的模式重叠。在串"...,382,382,..."有两次出现",382,"：

"...,382,382,..." 
    -----   first occurrence 
     -----  second occurrence 

这两个出现在逗号重叠，因此Java的只能更换其中的一个。发现事件时，它不会看到您将模式替换为什么，因此当替换第一个事件被替换为逗号时，不会看到生成新事件",382,"。

如果你的数据是已知不包含超过3个位数的数字，那么你可以做：

str.replace("382,", ""); 

，然后在年底作为特殊情况处理事件。但是如果你的数据可以包含大数字，那么"...,1382,..."将被"...,1,..."取代，这可能不是你想要的。

这里有没有上述问题，有两种解决方案：直到不再出现任何变化

首先，简单地重复更换：

String oldString = str; 
str = str.replace(",382,", ","); 
while (!str.equals(oldString)) { 
    oldString = str; 
    str = str.replace(",382,", ","); 
} 

之后，你将不得不处理可能发生在字符串的末尾。

第二，如果你对Java 8，你可以做更多的工作自己，用Java流：

str = Arrays.stream(str.split(",")) 
    .filter(s -> !s.equals("382")) 
    .collect(Collectors.joining(",")); 

这首先在分割字符串“”，然后筛选出哪些是相等的所有字符串到“382”，然后将剩余的字符串再次与“，”连接在一起。

（这两个代码片段都未经测试。）