英文:
How to filter parts of a string from an arraylist
问题
我有一个 ArrayList<String> listWithoutDuplicates，其中存储着如下元素：
[java.security.AlgorithmParameters.getInstance( alg);, java.security.AlgorithmParameters.getInstance( alg _);, java.security.AlgorithmParameters.init( params);, java.security.AlgorithmParameters.init( parAr);, java.security.AlgorithmParameters.init( parAr _);, parsRes = java.security.AlgorithmParameters.getEncoded();, parsRes = java.security.AlgorithmParameters.getEncoded( format);]
我尝试提取以下输出，并将其存储在另一个 List 中：
getInstance( alg)
getInstance( alg _)
init( params)
init( parAr)
init( parAr _)
getEncoded()
getEncoded( format)
我试图用 , 替换 .，现在我想要获取每个部分，在分号 ; 之前。
String sat = listWithoutDuplicates.toString().replace(".", ",");
List<String> answer = Arrays.asList(sat.split(";"));
有人能帮我处理一下吗？
最好的问候。
英文:
I have an ArrayList<String> listWithoutDuplicates which stores the elements like this:
[java.security.AlgorithmParameters.getInstance( alg);, java.security.AlgorithmParameters.getInstance( alg _);, java.security.AlgorithmParameters.init( params);, java.security.AlgorithmParameters.init( parAr);, java.security.AlgorithmParameters.init( parAr _);, parsRes = java.security.AlgorithmParameters.getEncoded();, parsRes = java.security.AlgorithmParameters.getEncoded( format);]
I'm trying to extract the following output and store this in another List:
getInstance( alg)
getInstance( alg _)
init( params)
init( parAr)
init( parAr _)
getEncoded()
getEncoded( format)
I tried to use the replace the . with , and now I'm trying to get every part which is before ;.
String sat = listWithoutDuplicates.toString().replace(".", ",");
List<String> answer = Arrays.asList(sat.split(";"));
Could somebody please help me with this.
Best regards.
答案1
得分: 0
str.replaceAll("(.*);", "$1");
这会得到分号之前的所有内容（注意这是在单个字符串上操作，不是在数组中的每个字符串上操作）。
这利用了正则表达式的分组属性。如果你不了解正则表达式，我强烈建议你阅读一些教程并尝试一下。（注意：不同的实现略有不同，所以你需要先了解其背后的原则，然后随着学习逐渐掌握每种实现（语言/框架）的“语法糖”）。
英文:
str.replaceAll("(.*);", "$1");
should get you everything before the ; (note this is on a single string, not each str in the array)
This makes use of the grouping property of regex (regular expression). If you don't know regex, then I HIGHLY recommend you go read some tutorials and try it out. (note: most different implementations are slightly different, so you'll have to learn the principles behind it and then learn the 'syntax sugar' of each implementation (which language/framework) as you go.)
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