java - 多行正则表达式匹配器

Question

有内容为输入文件:
XX00002200000
XX00003300000

正则表达式:

(.{6}22.{5}\W)(.{6}33.{5})

在 The Regex Coach(用于正则表达式测试的应用程序)中尝试过，字符串匹配正常。

Java:

        pattern = Pattern.compile(patternString);
        inputStream = resource.getInputStream();

        scanner = new Scanner(inputStream, charsetName);
        scanner.useDelimiter("\r\n");

patternString 是从 .xml 添加为 bean 属性的正则表达式(上面提到的)

Java 失败。

Answer 1

简单的解决方案:".{6}22.{5}\\s+.{6}33.{5}"。请注意 \s+ 是 shorthand对于后续的空白元素。

举个例子:

 public static void main(String[] argv) throws FileNotFoundException {
  String input = "yXX00002200000\r\nXX00003300000\nshort", regex = ".{6}22.{5}\\s+.{6}33.{5}", result = "";
  Pattern pattern = Pattern.compile(regex);
  Matcher m = pattern.matcher(input);

  while (m.find()) {
   result = m.group();
   System.out.println(result);
  }
 }

输出:

XX00002200000
XX00003300000

要尝试使用 Java Regex，您可以使用:Regular Expression Editor (免费在线编辑器)

编辑:我认为您在读取数据时正在更改输入，请尝试:

public static String readFile(String filename) throws FileNotFoundException {
    Scanner sc = new Scanner(new File(filename));

    StringBuilder sb = new StringBuilder();
    while (sc.hasNextLine())
        sb.append(sc.nextLine());
    sc.close();

    return sb.toString();
}

或者

static String readFile(String path) {
    FileInputStream stream = null;
    FileChannel channel = null;
    MappedByteBuffer buffer = null;

    try {
        stream = new FileInputStream(new File(path));
        channel = stream.getChannel();
        buffer = channel.map(FileChannel.MapMode.READ_ONLY, 0,
                channel.size());
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            stream.close();
        } catch (Exception e2) {
            e2.printStackTrace();
        }
    }

    return Charset.defaultCharset().decode(buffer).toString();
}

像这样导入:

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;
import java.util.regex.Matcher;
import java.util.regex.Pattern;