按新行拆分文本文件中的文本

Question

import java.io.*;
public class Wordcount {

    public static void main(String[] args) throws Exception {
        BufferedReader in = null;
        String[] splited = null;
        try {
            in = new BufferedReader(new FileReader("sample.txt"));
            String read = null;
            while ((read = in.readLine()) != null) {
                splited = read.split("systemSerialNumber:");
                for (String part : splited) {
                    System.out.println(part);
                }
            }
        } catch (IOException e) {
            System.out.println("There was a problem: " + e);
            e.printStackTrace();
        } finally {

            in.close();

        }

        System.out.println(splited[3]);
    }
}

"sample.txt" 文件包含以下文本。

"2018-10-16 19:54:26.691 [RawEventProcessor (2/2)] ERROR com.qolsys.iqcloud.processing.operators.RawEventProcessor1  - processRawPanelEvent():: SerialNumber systemSerialNumber: QV01D173700428AD is not mapped to any meid. {}",2
"2018-10-16 19:54:27.074 [RawEventProcessor (2/2)] ERROR com.qolsys.iqcloud.processing.operators.RawEventProcessor1  - processRawPanelEvent():: SerialNumber systemSerialNumber: QV01D173700428AD is not mapped to any meid. {}",2
"2018-10-16 19:54:27.293 [RawEventProcessor (2/2)] ERROR com.qolsys.iqcloud.processing.operators.RawEventProcessor1  - processRawPanelEvent():: SerialNumber systemSerialNumber: QV01D173700428AD is not mapped to any meid. {}",2
"2018-10-16 19:54:27.296 [RawEventProcessor (2/2)] ERROR com.qolsys.iqcloud.processing.operators.RawEventProcessor1  - processRawPanelEvent():: SerialNumber systemSerialNumber: QV01D173700428AD is not mapped to any meid. {}",2

我收到数组索引超出绑定异常的错误。以及为什么我会收到此异常，即使在拆分之后我也不知道所有文本文件数据都存储在数组的一个索引中。剩余为空。

堆栈跟踪：

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3 at Task1.Wordcount.main(Wordcount.java:29)

Answer 1

检查结果的长度是否为 2。最后一行可能为空。

Path path = Paths.get("sample.txt");
Files.lines(path, Charset.defaultCharset())
    .forEach(line -> {
        String[] splitted = read.split("systemSerialNumber:");
        if (splitted.length == 2) {
            ...
        }
    });

作为无关信息：

        String[] splitted = read.split("systemSerialNumber:", 2);

会将结果限制为最多 2 个元素，以防 "systemSerialNumber:" 出现不止一次。

按新行拆分文本文件中的文本

splitting a text in text file by new line

java

file

bufferedreader