Regular Expression matches multiple line example – Java

By mkyong | Updated: September 7, 2013

Viewed: 1,326 (+15 pv/w)

Tags: regex

By default, the “.” doesn’t match line breaks. To match multiple lines, add (?s) prefix or enable the Pattern.DOTALL flag.

1. Example

A address sample, we need to extract the “Address 1” only.

Starting...
Address 1: 88 app 2/8
	superman taman, puchong
	36100, Malaysia
Address 2: abc
End

Failed :
To extract “Address 1”, this pattern will return nothing, the “.” doesn’t match multiple lines.

Address 1:\\s(.*)Address 2:

Correct :
To extract “Address 1”, add (?s) prefix.

(?s)Address 1:\\s(.*)Address 2:

Or enable the Pattern.DOTALL mode.

Pattern.compile(Address 1:\\s(.*)Address 2:, Pattern.DOTALL);

2. RegEx Example

Example to use regex multiple lines matching to get the “Address 1” .

package com.mkyong.regex

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RunExampleTest{
	
	private Pattern addressPattern = Pattern.compile(ADDRESS_PATTERN);
	private Matcher matcher;

	//Alternative
	/*private Pattern addressPattern = 
		Pattern.compile(ADDRESS_PATTERN, Pattern.DOTALL);*/

	private static final String ADDRESS_PATTERN = "(?s)Address 1:\\s(.*)Address 2:";
	
	public static void main(String[] args) {
	
		String data = "Testing... \n" +
			"Address 1: 88 app 2/8\n" +
			"superman taman, puchong\n" +
			"36100, Malaysia\n" +
			"Address 2: abc" +
			"testing end";
		
		RunExampleTest obj = new RunExampleTest();
		List<String> list = obj.getAddress(data);
		
		System.out.println("Test Data : ");
		System.out.println(data + "\n");
		
		System.out.println("Address Resut : " + list);
		
	}
	
	private List<String> getAddress(String data){
		
		List<String> result = new ArrayList<String>();
		
		matcher = addressPattern.matcher(data);

		while (matcher.find()) {
			result.add(matcher.group(1));
		}
		
		return result;
	}
	
}

Output

Test Data : 
Testing... 
Address 1: 88 app 2/8
superman taman, puchong
47100, Malaysia
Address 2: abctesting end

Result : [88 app 2/8
superman taman, puchong
47100, Malaysia
]

References

1. Emacs Multiline Regexp example
2. Wikipedia : Regular Expression/