正则表达式中的反斜杠

import java.util.regex.Matcher;

import java.util.regex.Pattern;
//n o w  j a v a  . c o m 提供

public class Main {

  public static void main(String[] argv) {

    String rep = "a\\\\b";

    String input = "> XYZ <=> ABC <";

    Pattern pattern = Pattern.compile("ABC|XYZ");

    Matcher matcher = pattern.matcher(input);


    System.out.println(matcher.replaceFirst(rep));

    System.out.println(matcher.replaceAll(rep));


    rep = "\\\\r\\\\n";

    input = "line 1\nline 2\nline 3\n";

    pattern = Pattern.compile("\\n");

    matcher = pattern.matcher(input);


    System.out.println("");

    System.out.println("Before:");