如何拆分字符串，删除最后一个元素并在Java中加入？

Question

我有一个包含文件名的数组变量filesFound。如何删除最后一个数字部分，包括其扩展名。

...
File[] filesFound = SomeUtils.findFile("xyz","c:\\") 

//fileFound[0] is now "abc_xyz_pqr_27062016.csv"
//What I need is "abc_xyz_pqr" only

String[] t = filesFound[0].toString().split("_")
Arrays.copyOf(t, t.length - 1) //this is not working
...

Answer 1

复制数组不会将这些部分连接在一起。试试

StringBuilder builder = new StringBuilder();
for (int i = 0; i < t.length - 1; i++) {
    builder.append(t[i]);
}
String joined = builder.toString();

Answer 2

Arrays.copyOf返回一个新数组，因此您必须将其分配给t或新变量：

t = Arrays.copyOf(t, t.length - 1)

Answer 3

正则表达式：

System.out.println("abc_xyz_pqr_27062016.csv");       

System.out.println("abc_xyz_pqr_27062016.csv".replaceAll("_\\d+.+",""));

打印出来：

abc_xyz_pqr_27062016.csv
abc_xyz_pqr

Answer 4

有点紧张..

            //fileFound[0] is now "abc_xyz_pqr_27062016.csv"

            String file = fileFound[0] ;
            String filter = "";
            int i = 0;
            char [] allChars = file.toCharArray();
            char oneChar ;
            while(i < (file.length()-4)){//4 is .csv
                oneChar = allChars[i];
                if((oneChar >= 65 && oneChar <=90)||(oneChar >= 97 && oneChar <=122)|| oneChar==95){
                    filter += oneChar;
                }
                i++;

            }
            filter = filter.substring(0, filter.length()-1);
            System.out.println(filter);

这很好用

Answer 5

.substring()＆amp; .lastIndexOf()？

String file = filesFound[0];
String newFileName = file.substring(0, file.lastIndexOf("_"));

newFileName将包含最后（但不包括）最后一个＆＃39; _＆＃39;炭。