[英]Java Reading a txt that has different numbers in its column file and store data in an arraylist
Hello Guys I have a txt file below, I need to store the second column data but it gives me an error since some lines have 1 some have 2 and some have 3 input in each line.大家好,我在下面有一个 txt 文件,我需要存储第二列数据,但它给了我一个错误,因为有些行有 1,有些有 2,有些每行有 3 个输入。 How can I solve that problem?
我该如何解决这个问题?
5
3 4
3 4
3 3
3 4
3 3
3 4
3 3
3 2
3 4
3 3
3 2
3 1
3 4
3 3
3 2
3 1
3 0
1
2
5 3 4
3 4
3 4
3 3
3 4
3 3
3 4
3 3
3 2
3 4
3 3
3 2
3 1
3 4
3 3
3 2
3 1
3 0
1
2
5 4 6
4 4
4 4
4 4
4 4
4 4
4 4
4 3
4 3
4 3
4 3
4 4
4 4
1
2
5 4 6
0
Here is what I did, I tried to differentiate as the size and in the other way but still cant get the answer...这就是我所做的,我试图区分大小和其他方式,但仍然无法得到答案......
String line = "";
ArrayList<String> numbers= new ArrayList<String>();
try {
String sCurrentLine;
br = new BufferedReader(new FileReader("input1.txt"));
int n = 0;
while ((sCurrentLine = br.readLine()) != null) {
String[] arr = sCurrentLine.split(" ");
int size = arr.length;
List<String> list = ConvertToList.convertArrayToList(arr);
List<Integer> listOfInteger = convert.convertStringListToIntList(list, Integer::parseInt);
if (list.size() == 2) {
line.split("\\s+");
numbers.add(line.split("\\s+")[0]);
System.out.println(numbers);
}
}
} catch(Exception e) {
e.printStackTrace();
}
You do not need to split the line again.您无需再次拆分线路。 When you split the line first time, check if the length of the resulting array is
2
.第一次拆分行时,检查结果数组的长度是否为
2
。 If yes, add arr[1]
to numbers
.如果是,请将
arr[1]
添加到numbers
。
while ((sCurrentLine = br.readLine()) != null) {
String[] arr = sCurrentLine.split(" ");
if (arr.length >= 2) {
numbers.add(arr[1]);
System.out.println(numbers);
}
}
Based on your comment, I am providing you following code which uses your lists:根据您的评论,我为您提供以下使用您的列表的代码:
while ((sCurrentLine = br.readLine()) != null) {
String[] arr = sCurrentLine.split(" ");
List<String> list = ConvertToList.convertArrayToList(arr);
List<Integer> listOfInteger = convert.convertStringListToIntList(list, Integer::parseInt);
if (listOfInteger.size() >= 2) {
numbers.add(listOfInteger.get(1));
}
}
System.out.println(numbers);
You can keep System.out.println(numbers);
您可以保留
System.out.println(numbers);
inside or outside the while
loop depending on how you want to print numbers
.在
while
循环内部或外部,具体取决于您要如何打印numbers
。
If you want to read and save only the second column than you get the data in second column by using the index 1. (After your while loop.)如果您只想读取和保存第二列而不是使用索引 1 获取第二列中的数据。(在您的 while 循环之后。)
String secondCol = sCurrentLine.split(" ")[1];
In case you don't have a value in 2 column than it will throw and exception which you should handle with simple try catch.如果您在 2 列中没有值,则会抛出异常,您应该使用简单的 try catch 处理。 Finally convert it to int and store in your list.
最后将其转换为 int 并存储在您的列表中。 with following.
与以下。
listOfInteger.add(Integer.parseInt(secoundCol));
Hopefully it will work.希望它会奏效。
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