Question

我尝试用逗号分割文本并添加到每个列表中。文字样本：

用户1，角色1

用户2，角色2
  用户3，角色3
 user 4 , role 4

 user 5 , role 5

功能：

private Map<Integer, List<String>> map = new HashMap<Integer, List<String>>();
public String splitString(String sentence) {
    List<String> list;
    String[] dividedByNewLine = sentence.split("\n");
    for (int i = 0; i < dividedByNewLine.length; i++) {
            String[] divideByComma = dividedByNewLine[i].split(",");
            list = new ArrayList<String>();
            for (int j = 0; j < divideByComma.length; j++) {
                list.add(divideByComma[j].trim());
            }
            if (!list.isEmpty()) {
                map.put(i, list);
            }
            System.out.println(map.get(i));

    }

    return null;
}

但功能构建列表如下：

[用户1，角色1]

[]

[用户2，角色2]

[用户3，角色3]

[]

[用户4，角色4]

[]

[用户5，角色5]

如何删除＆＃34; []＆＃34;在列表中？

Answer 1

因为您的输入有空行。如果您不想显示空行，您的代码应为：

for (int i = 0; i < dividedByNewLine.length; i++) {
    if (!dividedByNewLine[i].trim().isEmpty()){
      String[] divideByComma = dividedByNewLine[i].split(",");
            list = new ArrayList<String>();
            for (int j = 0; j < divideByComma.length; j++) {
                list.add(divideByComma[j].trim());
            }
            if (!list.isEmpty()) {
                map.put(i, list);
            }
            System.out.println(map.get(i));
   }
}

Answer 2

在dividedByNewLine中搜索所有空行并删除它们！然后你会得到

user 1 , role 1
user 2 , role 2
user 3 , role 3
user 4 , role 4
user 5 , role 5

dividedByNewLine[i].split(",")或dividedByNewLine非for (int i = 0; i < dividedByNewLine.length; i++) { if(!dividedByNewLine[i].isEmpty()) { String[] divideByComma = dividedByNewLine[i].split(","); ... } }非空：

{{1}}

Answer 3

试试这个for循环：

for (int i = 0; i < dividedByNewLine.length; i++) {
        if(!dividedByNewLine[i].trim().equals("")) {
            String[] divideByComma = dividedByNewLine[i].split(",");

        list = new ArrayList<String>();
        for (int j = 0; j < divideByComma.length; j++) {
            list.add(divideByComma[j].trim());
        }
        if (!list.isEmpty()) {
            map.put(i, list);
        }
        System.out.println(map.get(i));
        }
}

基本上，你必须跳过空行。

Answer 4

您可以在添加到列表之前消除[]： -

for (int i = 0; i < dividedByNewLine.length; i++) {
        String[] divideByComma = dividedByNewLine[i].split(",");

        //Add this control statement
        if(divideByComma.isEmpty())
        continue;       //If the string is empty then continue the loop

        list = new ArrayList<String>();
        for (int j = 0; j < divideByComma.length; j++) {
            list.add(divideByComma[j].trim());
        }
        if (!list.isEmpty()) {
            map.put(i, list);
        }
        System.out.println(map.get(i));

}

拆分并删除新行

4 个答案: