java - 当我们有特定文本到模式时，正则表达式 Java

Question

As i haven't much worked on regex, can someone help me out in getting the answer for below thing:

(1)我想删除元素文本

(2)后面可能不跟分隔符，比如管道(||)

I tried below thing, but it is not working in the way i want:

String str = "String:abc||Element:abc||Value:abc"; // Sample text 1
String str1 = "String:abc||Element:abc"; // Sample text 2
System.out.println(str.replaceFirst("Element.*\\||", ""));
System.out.println(str1.replaceFirst("Element.*\\||", ""));

Required output in above cases:

String:abc||Value:abc //for the first case
String:abc //for the second case

Answer 1

假设您可以决定为原始模式赋予另一个值，在本例中为 Element，您可以使用 Pattern.quote 对其进行转义，如下所示:

String str = "String:abc||Element:abc||Value:abc"; // Sample text 1
String str1 = "String:abc||Element:abc"; // Sample text 2
String originalPattern = "Element";
String pattern = String.format("\\|{2}%s[^\\|]+", Pattern.quote(originalPattern));
System.out.println(str.replaceFirst(pattern, ""));
System.out.println(str1.replaceFirst(pattern, ""));

您的模式是通用的，其值为 String.format("\\|{2}%s[^\\|]+", Pattern.quote(originalPattern))输出:

String:abc||Value:abc
String:abc