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Java生成短链

2015/3/4 12:12:12 lfl2011 程序员俱乐部我要评论(0)

摘要：生成思路：1.将"原始链接（长链接）+key(自定义字符串,防止算法泄漏)"MD5加密2.把加密字符按照8位一组16进制与0x3FFFFFFF进行位与运算，把得到的值与0x0000003D进行位与运算，取得字符数组chars索引，把取得的字符相加，每次循环按位右移5位，把字符串存入对应索引的输出数组(4组6位字符串)3.生成4以下的随机数，从输入数组中取出随机数对应位置的字符串，作为短链，存入数据库或者NoSql解析方式编写一个web处理程序,把从ur(如:http://url.51bi
标签：Java

生成思路：

1.将"原始链接（长链接）+key(自定义字符串,防止算法泄漏)"MD5加密

2.把加密字符按照 8 位一组 16 进制与 0x3FFFFFFF 进行位与运算，把得到的值与 0x0000003D 进行位与运算，取得字符数组 chars 索引，把取得的字符相加，每次循环按位右移 5 位，把字符串存入对应索引的输出数组(4组6位字符串)

3.生成4以下的随机数，从输入数组中取出随机数对应位置的字符串，作为短链，存入数据库或者NoSql

解析方式

编写一个web处理程序,把从ur(如:http://url.51bi.com/zAnuAn)中解析短链接,将解析到的短链接(zAnuAn)与数据库中存入的原始链接进行匹配，跳转到匹配到的原始链接。

class="java">package com.bjdata.test;

import java.security.MessageDigest;
import java.util.Random;


public class ShortUrlTest {
    public static void main(String[] args) {
        String sLongUrl = "http://www.51bi.com/bbs/_t_278433840/"; // 原始链接
        System.out.println("长链接:"+sLongUrl);
        String[] aResult = shortUrl(sLongUrl);//将产生4组6位字符串
        // 打印出结果
        for (int i = 0; i < aResult.length; i++) {
            System.out.println("[" + i + "]:" + aResult[i]);
        }
        Random random=new Random();
        int j=random.nextInt(4);//产成4以内随机数
        System.out.println("短链接:"+aResult[j]);//随机取一个作为短链
    }

    public static String[] shortUrl(String url) {
        // 可以自定义生成 MD5 加密字符传前的混合 KEY
        String key = "test";
        // 要使用生成 URL 的字符
        String[] chars = new String[] { "a", "b", "c", "d", "e", "f", "g", "h",
                "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t",
                "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5",
                "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H",
                "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T",
                "U", "V", "W", "X", "Y", "Z"

        };
        // 对传入网址进行 MD5 加密
        String hex = md5ByHex(key + url);

        String[] resUrl = new String[4];
        for (int i = 0; i < 4; i++) {

            // 把加密字符按照 8 位一组 16 进制与 0x3FFFFFFF 进行位与运算
            String sTempSubString = hex.substring(i * 8, i * 8 + 8);

            // 这里需要使用 long 型来转换，因为 Inteper .parseInt() 只能处理 31 位 , 首位为符号位 , 如果不用long ，则会越界
            long lHexLong = 0x3FFFFFFF & Long.parseLong(sTempSubString, 16);
            String outChars = "";
            for (int j = 0; j < 6; j++) {
                // 把得到的值与 0x0000003D 进行位与运算，取得字符数组 chars 索引
                long index = 0x0000003D & lHexLong;
                // 把取得的字符相加
                outChars += chars[(int) index];
                // 每次循环按位右移 5 位
                lHexLong = lHexLong >> 5;
            }
            // 把字符串存入对应索引的输出数组
            resUrl[i] = outChars;
        }
        return resUrl;
    }
    /**
     * MD5加密(32位大写)    
     * @param src
     * @return
     */
    public static String md5ByHex(String src) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] b = src.getBytes();
            md.reset();
            md.update(b);
            byte[] hash = md.digest();
            String hs = "";
            String stmp = "";
            for (int i = 0; i < hash.length; i++) {
                stmp = Integer.toHexString(hash[i] & 0xFF);
                if (stmp.length() == 1)
                    hs = hs + "0" + stmp;
                else {
                    hs = hs + stmp;
                }
            }
            return hs.toUpperCase();
        } catch (Exception e) {
            return "";
        }
    }

}

运行结果

长链接:http://www.51bi.com/bbs/_t_278433840/
[0]:fa6bUr
[1]:ryEfeq
[2]:zAnuAn
[3]:auIJne
短链接:zAnuAn

分享sina的短链生成java代码

比如可以将http://zuidaima.com/转换为http://t.cn/zlsvWVq

如下图：

package com.zuidaima.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Map;
import java.util.LinkedHashMap;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ShortenUrl {

	private static final boolean DEBUG = true;

	public static void main(String[] args) {
		String url = "http://www.henshiyong.com/tools/sina-shorten-url.php";
		Map<String, String> params = new LinkedHashMap<String, String>();
		params.put("url", "http://www.google.com");
		params.put("submit", "转换");

		String data = null;

		try {
			data = postUrl(url, params);
			if (DEBUG) {
				System.out.println(data);
			}
		} catch (IOException ex) {
		}

		if (data != null) {
			String shortUrl = getShortenUrl(data);
			if (DEBUG) {
				System.out.println(shortUrl);
			}
		}
	}

	public static String getShortenUrl(String content) {
		String url = null;
		List<String> resultList = getContext(content);

		for (Iterator<String> iterator = resultList.iterator(); iterator
				.hasNext();) {
			url = iterator.next();
		}

		return url;
	}

	/**
	 * Extract "XXXX" from "<textarea>XXXX</textarea>"
	 * 
	 * @param html
	 * @return
	 */
	public static List<String> getContext(String html) {
		List<String> resultList = new ArrayList<String>();
		Pattern p = Pattern.compile("<textarea>(.*)</textarea>");
		Matcher m = p.matcher(html);
		while (m.find()) {
			resultList.add(m.group(1));
		}
		return resultList;
	}

	public static class HttpException extends RuntimeException {

		private int errorCode;
		private String errorData;

		public HttpException(int errorCode, String errorData) {
			super("HTTP Code " + errorCode + " : " + errorData);
			this.errorCode = errorCode;
			this.errorData = errorData;
		}

		public int getErrorCode() {
			return errorCode;
		}

		public String getErrorData() {
			return errorData;
		}

	}

	public static String postUrl(String url, Map<String, String> params)
			throws IOException {
		String data = "";
		for (String key : params.keySet()) {
			data += "&" + URLEncoder.encode(key, "UTF-8") + "="
					+ URLEncoder.encode(params.get(key), "UTF-8");
		}
		data = data.substring(1);
		// System.out.println(data);
		URL aURL = new java.net.URL(url);
		HttpURLConnection aConnection = (java.net.HttpURLConnection) aURL
				.openConnection();
		try {
			aConnection.setDoOutput(true);
			aConnection.setDoInput(true);
			aConnection.setRequestMethod("POST");
			// aConnection.setAllowUserInteraction(false);
			// POST the data
			OutputStreamWriter streamToAuthorize = new java.io.OutputStreamWriter(
					aConnection.getOutputStream());
			streamToAuthorize.write(data);
			streamToAuthorize.flush();
			streamToAuthorize.close();

			// check error
			int errorCode = aConnection.getResponseCode();
			if (errorCode >= 400) {
				InputStream errorStream = aConnection.getErrorStream();
				try {
					String errorData = streamToString(errorStream);
					throw new HttpException(errorCode, errorData);
				} finally {
					errorStream.close();
				}
			}

			// Get the Response
			InputStream resultStream = aConnection.getInputStream();
			try {
				String responseData = streamToString(resultStream);
				return responseData;
			} finally {
				resultStream.close();
			}
		} finally {
			aConnection.disconnect();
		}
	}

	private static String streamToString(InputStream resultStream)
			throws IOException {
		BufferedReader aReader = new java.io.BufferedReader(
				new java.io.InputStreamReader(resultStream));
		StringBuffer aResponse = new StringBuffer();
		String aLine = aReader.readLine();
		while (aLine != null) {
			aResponse.append(aLine + "\n");
			aLine = aReader.readLine();
		}
		return aResponse.toString();

	}
}

完整分享代码下载地址:http://www.zuidaima.com/share/1550463367924736.htm

转自：http://www.cnblogs.com/zhanghaoh/archive/2012/12/24/2831264.html

?????????? http://blog.csdn.net/yaerfeng/article/details/20289791