http提取工具类

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

class Test

{
	private static String tmp;

	/**
     * 以行为单位读取文件，常用于读面向行的格式化文件
     */
    public static String readFileByLines(String fileName) {
        File file = new File(fileName);
        BufferedReader reader = null;
        String tempString = null;
        String tmp=null;
        try {
            System.out.println("以行为单位读取文件内容，一次读一整行：");
            reader = new BufferedReader(new FileReader(file));
            int line = 1;
            // 一次读入一行，直到读入null为文件结束
            while ((tempString = reader.readLine()) != null) {
                // 显示行号
                System.out.println("line " + line + ": " + tempString);
                tmp+=tempString;
                line++;
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e1) {
                }
            }
        }
		return tmp;
    }



	public static void main(String[] args)

	{

		Pattern pattern = Pattern.compile("http://[\\w\\.\\-/:]+");
		String str  = readFileByLines("maps");

		Matcher matcher = pattern.matcher(str);

		StringBuffer buffer = new StringBuffer();

		while (matcher.find()) {

			buffer.append(matcher.group());

			buffer.append("\r\n");

		}

		System.out.println(buffer.toString());

	}

}