Browse Source

feat:完成Redis缓存和布隆过滤器检查

master
Naccl 4 years ago
parent
commit
539b4e5b0c
  1. 16
      src/main/java/top/naccl/dwz/controller/IndexController.java
  2. 4
      src/main/java/top/naccl/dwz/entity/UrlMap.java
  3. 2
      src/main/java/top/naccl/dwz/service/UrlService.java
  4. 58
      src/main/java/top/naccl/dwz/service/impl/UrlServiceImpl.java

16
src/main/java/top/naccl/dwz/controller/IndexController.java

@ -4,6 +4,7 @@ import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
@ -37,11 +38,20 @@ public class IndexController {
@ResponseBody
public R generateShortURL(@RequestParam String longURL) {
if (UrlUtils.checkURL(longURL)) {
String shortURL = urlService.saveUrlMap(HashUtils.hashToBase62(longURL), longURL);
String shortURL = urlService.saveUrlMap(HashUtils.hashToBase62(longURL), longURL, longURL);
return R.ok("请求成功", host + shortURL);
} else {
return R.create(400, "URL有误");
}
return R.create(400, "URL有误");
}
@GetMapping("/{shortURL}")
public String redirect(@PathVariable String shortURL) {
String longURL = urlService.getLongUrlByShortUrl(shortURL);
if (longURL != null) {
//查询到对应的原始链接,302重定向
return "redirect:" + longURL;
}
//没有对应的原始链接,直接返回首页
return "redirect:/";
}
}

4
src/main/java/top/naccl/dwz/entity/UrlMap.java

@ -22,9 +22,9 @@ public class UrlMap {
private String lurl;//长链接
private Date createTime;//创建时间
public UrlMap(String surl, String lurl, Date createTime) {
public UrlMap(String surl, String lurl) {
this.surl = surl;
this.lurl = lurl;
this.createTime = createTime;
this.createTime = new Date();
}
}

2
src/main/java/top/naccl/dwz/service/UrlService.java

@ -3,5 +3,5 @@ package top.naccl.dwz.service;
public interface UrlService {
String getLongUrlByShortUrl(String shortURL);
String saveUrlMap(String shortURL, String longURL);
String saveUrlMap(String shortURL, String longURL, String originalURL);
}

58
src/main/java/top/naccl/dwz/service/impl/UrlServiceImpl.java

@ -1,14 +1,17 @@
package top.naccl.dwz.service.impl;
import cn.hutool.bloomfilter.BitMapBloomFilter;
import cn.hutool.bloomfilter.BloomFilterUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DuplicateKeyException;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import top.naccl.dwz.entity.UrlMap;
import top.naccl.dwz.mapper.UrlMapper;
import top.naccl.dwz.service.UrlService;
import top.naccl.dwz.util.HashUtils;
import java.util.Date;
import java.util.concurrent.TimeUnit;
/**
* @Description: 长短链接映射业务层实现
@ -19,33 +22,58 @@ import java.util.Date;
public class UrlServiceImpl implements UrlService {
@Autowired
UrlMapper urlMapper;
private static final String DUPLICATE = " *";
@Autowired
StringRedisTemplate redisTemplate;
//自定义长链接防重复字符串
private static final String DUPLICATE = "*";
//最近使用的短链接过期时间(分钟)
private static final long TIMEOUT = 10;
//创建布隆过滤器
private static final BitMapBloomFilter FILTER = BloomFilterUtil.createBitMap(10);
@Override
public String getLongUrlByShortUrl(String shortURL) {
return urlMapper.getLongUrlByShortUrl(shortURL).replace(DUPLICATE, "");
//查找Redis中是否有缓存
String longURL = redisTemplate.opsForValue().get(shortURL);
if (longURL != null) {
//有缓存
return longURL;
}
//Redis没有缓存,从数据库查找
return urlMapper.getLongUrlByShortUrl(shortURL);
}
@Override
public String saveUrlMap(String shortURL, String longURL) {
public String saveUrlMap(String shortURL, String longURL, String originalURL) {
//保留长度为1的短链接
if (shortURL.length() == 1) {
longURL += DUPLICATE;
shortURL = saveUrlMap(HashUtils.hashToBase62(longURL), longURL, originalURL);
}
//在布隆过滤器中查找是否存在
if (judgeExist()) {
//存在,在长链接后加上指定字符串,重新hash
else if (FILTER.contains(shortURL)) {
//存在,从Redis中查找是否有缓存
String redisLongURL = redisTemplate.opsForValue().get(shortURL);
if (redisLongURL != null && originalURL.equals(redisLongURL)) {
//Redis有缓存,重置过期时间
redisTemplate.expire(shortURL, TIMEOUT, TimeUnit.MINUTES);
return shortURL;
}
//没有缓存,在长链接后加上指定字符串,重新hash
longURL += DUPLICATE;
shortURL = HashUtils.hashToBase62(longURL);
shortURL = saveUrlMap(shortURL, longURL);
return shortURL;
shortURL = saveUrlMap(HashUtils.hashToBase62(longURL), longURL, originalURL);
} else {
//不存在,直接存入数据库
try {
urlMapper.saveUrlMap(new UrlMap(shortURL, longURL, new Date()));
urlMapper.saveUrlMap(new UrlMap(shortURL, originalURL));
FILTER.add(shortURL);
//添加缓存
redisTemplate.opsForValue().set(shortURL, originalURL, TIMEOUT, TimeUnit.MINUTES);
} catch (Exception e) {
if (e instanceof DuplicateKeyException) {
//数据库已经存在此短链接,则可能是布隆过滤器误判,在长链接后加上指定字符串,重新hash
longURL += DUPLICATE;
shortURL = HashUtils.hashToBase62(longURL);
shortURL = saveUrlMap(shortURL, longURL);
return shortURL;
shortURL = saveUrlMap(HashUtils.hashToBase62(longURL), longURL, originalURL);
} else {
throw e;
}
@ -53,8 +81,4 @@ public class UrlServiceImpl implements UrlService {
}
return shortURL;
}
public boolean judgeExist() {
return false;
}
}

Loading…
Cancel
Save