你知道的越多，你不知道的越多
点赞再看，养成习惯
如果您有疑问或者见解，欢迎指教：
企鹅：869192208
文章目录
前言
工作中经常有一些将需要访问的链接转成二维码的场景，此时如果链接中的内容过长，那么生成出来的二维码图片就需要设置很大尺寸，才能让手机扫码识别，且生成的二维码看起来很密，视觉效果不好。此时就需要使用到长链接转短链接，生成二维码的时候，使用的是短链接，扫码后，再由短链接重定向到实际的链接（长链接）。
Controller代码
部分代码省略
@RestController
@RequestMapping(value="api/short/")
public class ShortConnectController {
@Autowired
private ApprShortService shortService;
/**
* 获取短连接
* @param
* @param request
* @throws IOException
*/
@GetMapping("/getShortUrl")
public String getShortUrl(HttpServletRequest request) throws IOException {
try {
Map param = WebUtil.getParamMap(request);
return shortService.getShortUrl(param);
} catch (Exception e) {
e.printStackTrace();
return "生成短连接失败";
}
}
/**
*
* 短连接转发
* @param shortUrlCode
* @param response
* @throws IOException
*/
@RequestMapping("/{shortUrlCode}")
public void redirectLongUrl(@PathVariable String shortUrlCode, HttpServletResponse response) throws IOException {
//记录一下访问次数
StringBuffer ractUrl = new StringBuffer();
//判断链接是否失效
List<String> realUrlList = shortService.queryLongUrl(shortUrlCode);
if(realUrlList !=null && realUrlList.size()>0){
String realUrl = realUrlList.get(0);
String urls[] = realUrl.split("[?]");
for(int i =0 ;i<urls.length ;i ++){
if(i == 0){
ractUrl.append(urls[i]).append("?");
}else{
String arrSplit [] =urls[i].split("[&]");
for(String strSplit:arrSplit){
String[] arrSplitEqual=null;
arrSplitEqual= strSplit.split("[=]");
ractUrl.append("&");
//解析出键值
if(arrSplitEqual.length>1){
ractUrl.append(arrSplitEqual[0]).append("=") ;
ractUrl.append( URLEncoder.encode(arrSplitEqual[1],"UTF-8"));
}else{
if(arrSplitEqual[0]!=""){
ractUrl.append(arrSplitEqual[0]).append("=").append("");
}
}
}
}
}
}
response.setStatus(302);
response.setHeader("Location", ractUrl.toString());//设置新请求的URL
}
}
WebUtil代码
部分代码省略
import org.apache.commons.lang3.StringUtils;
import javax.servlet.http.HttpServletRequest;
public class WebUtil {
@SuppressWarnings({ "unchecked", "rawtypes" })
public static Map getParamMap(HttpServletRequest request) {
Map result = new HashMap(12);
Map temp = request.getParameterMap();
Iterator ite = temp.keySet().iterator();
while (ite.hasNext()) {
String key = (String) ite.next();
String[] arge = (String[]) temp.get(key);
if (arge.length > 0 && StringUtils.isNotEmpty(arge[0])
&& !"\"null\"".equals(arge[0]) && !"null".equals(arge[0])) {
result.put(key, arge[0].trim());
}
}
return result;
}
}
Service代码
部分代码省略
@Service
@RefreshScope
public class ApprShortServiceImpl {
@Autowired
private ApprShortConnectionDao apprShortConnectionMapper;
//生成短连接访问地址的ip端口 或者是域名
private String SHORT = "http://192.168.0.2:9200/short-platform-service/";
public String getShortUrl(Map param) throws Exception{
IdWorker worker = new IdWorker(1,1,5);
long Id = worker.nextId();
ApprShortConnection shortConnection = new ApprShortConnection();
shortConnection.setId(String.valueOf(Id));
shortConnection.setCreateTime(new Date());
shortConnection.setStatus("1");
shortConnection.setPassword(String.valueOf(Id));
String longUrl = param.get("longUrl").toString();
longUrl = URLDecoder.decode(longUrl,"utf-8") ;
longUrl = Base64Util.decode(longUrl) ;
System.out.println("解析后的longUrl"+longUrl);
shortConnection.setUrl(longUrl);
shortConnection.setTag("2");
apprShortConnectionMapper.insert(shortConnection);
return SHORT + "api/short/"+Id;
}
/**
* 根据id获取真实请求地址
* @param code
* @return
*/
public List<String> queryLongUrl(String code) {
ApprShortConnection shortConnection = new ApprShortConnection();
shortConnection.setId(code);
return apprShortConnectionMapper.queryUrlById(shortConnection);
}
}
IdWorker代码
/**
* 使用雪花算法生成全局唯一id
*/
public class IdWorker {
//因为二进制里第一个 bit 为如果是 1，那么都是负数，但是我们生成的 id 都是正数，所以第一个 bit 统一都是 0。
//机器ID 2进制5位 32位减掉1位 31个
private long workerId;
//机房ID 2进制5位 32位减掉1位 31个
private long datacenterId;
//代表一毫秒内生成的多个id的最新序号 12位 4096 -1 = 4095 个
private long sequence;
//设置一个时间初始值 2^41 - 1 差不多可以用69年
private long twepoch = 1585644268888L;
//5位的机器id
private long workerIdBits = 5L;
//5位的机房id
private long datacenterIdBits = 5L;
//每毫秒内产生的id数 2 的 12次方
private long sequenceBits = 12L;
// 这个是二进制运算，就是5 bit最多只能有31个数字，也就是说机器id最多只能是32以内
private long maxWorkerId = -1L ^ (-1L << workerIdBits);
// 这个是一个意思，就是5 bit最多只能有31个数字，机房id最多只能是32以内
private long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
private long workerIdShift = sequenceBits;
private long datacenterIdShift = sequenceBits + workerIdBits;
private long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
private long sequenceMask = -1L ^ (-1L << sequenceBits);
//记录产生时间毫秒数，判断是否是同1毫秒
private long lastTimestamp = -1L;
public long getWorkerId(){
return workerId;
}
public long getDatacenterId() {
return datacenterId;
}
public long getTimestamp() {
return System.currentTimeMillis();
}
public IdWorker(long workerId, long datacenterId, long sequence) {
// 检查机房id和机器id是否超过31 不能小于0
if (workerId > maxWorkerId || workerId < 0) {
throw new IllegalArgumentException(
String.format("worker Id can't be greater than %d or less than 0",maxWorkerId));
}
if (datacenterId > maxDatacenterId || datacenterId < 0) {
throw new IllegalArgumentException(
String.format("datacenter Id can't be greater than %d or less than 0",maxDatacenterId));
}
this.workerId = workerId;
this.datacenterId = datacenterId;
this.sequence = sequence;
}
// 这个是核心方法，通过调用nextId()方法，让当前这台机器上的snowflake算法程序生成一个全局唯一的id
public synchronized long nextId() {
// 这儿就是获取当前时间戳，单位是毫秒
long timestamp = timeGen();
if (timestamp < lastTimestamp) {
System.err.printf(
"clock is moving backwards. Rejecting requests until %d.", lastTimestamp);
throw new RuntimeException(
String.format("Clock moved backwards. Refusing to generate id for %d milliseconds",
lastTimestamp - timestamp));
}
// 下面是说假设在同一个毫秒内，又发送了一个请求生成一个id
// 这个时候就得把seqence序号给递增1，最多就是4096
if (lastTimestamp == timestamp) {
// 这个意思是说一个毫秒内最多只能有4096个数字，无论你传递多少进来，
//这个位运算保证始终就是在4096这个范围内，避免你自己传递个sequence超过了4096这个范围
sequence = (sequence + 1) & sequenceMask;
//当某一毫秒的时间，产生的id数 超过4095，系统会进入等待，直到下一毫秒，系统继续产生ID
if (sequence == 0) {
timestamp = tilNextMillis(lastTimestamp);
}
} else {
sequence = 0;
}
// 这儿记录一下最近一次生成id的时间戳，单位是毫秒
lastTimestamp = timestamp;
// 这儿就是最核心的二进制位运算操作，生成一个64bit的id
// 先将当前时间戳左移，放到41 bit那儿；将机房id左移放到5 bit那儿；将机器id左移放到5 bit那儿；将序号放最后12 bit
// 最后拼接起来成一个64 bit的二进制数字，转换成10进制就是个long型
return ((timestamp - twepoch) << timestampLeftShift) |
(datacenterId << datacenterIdShift) |
(workerId << workerIdShift) | sequence;
}
/**
* 当某一毫秒的时间，产生的id数 超过4095，系统会进入等待，直到下一毫秒，系统继续产生ID
* @param lastTimestamp
* @return
*/
private long tilNextMillis(long lastTimestamp) {
long timestamp = timeGen();
while (timestamp <= lastTimestamp) {
timestamp = timeGen();
}
return timestamp;
}
//获取当前时间戳
private long timeGen(){
return System.currentTimeMillis();
}
/**
* main 测试类
* @param args
*/
public static void main(String[] args) {
System.out.println(1&4596);
System.out.println(2&4596);
System.out.println(6&4596);
System.out.println(6&4596);
System.out.println(6&4596);
System.out.println(6&4596);
IdWorker worker = new IdWorker(1,1,5);
for (int i = 0; i < 22; i++) {
System.out.println(worker.nextId());
}
}
}
ApprShortConnection代码
import java.io.Serializable;
import java.util.Date;
@Data
public class ApprShortConnection implements Serializable {
private String id;
private String url;
private String password;
private String status;
private String tag;
private Date createTime;
private byte[] params;
private static final long serialVersionUID = 1L;
}
Mybatis代码
部分代码省略
<insert id="insert" parameterType="com.xymy.short.platform.service.shortConnect.model.ApprShortConnection">
insert into APPR_SHORT_CONNECTION (ID, URL, PASSWORD,
STATUS, TAG, CREATE_TIME)
values (#{id,jdbcType=VARCHAR}, #{url,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR},
#{status,jdbcType=VARCHAR}, #{tag,jdbcType=VARCHAR}, #{createTime,jdbcType=TIMESTAMP})
</insert>
<select id="queryUrlById" parameterType="com.minstone.appr.platform.acl.shortConnect.model.ApprShortConnection"
resultType="string" >
select url from APPR_SHORT_CONNECTION
where id = #{id,jdbcType=VARCHAR}
</select>
APPR_SHORT_CONNECTION建表语句
create table APPR_SHORT_CONNECTION
(
ID VARCHAR(50) not null,
URL VARCHAR(2000) not null,
PASSWORD VARCHAR(20) not null,
STATUS VARCHAR(2) not null,
TAG VARCHAR(2) not null,
CREATE_TIME TIMESTAMP,
PARAMS CLOB
);
comment
on table APPR_SHORT_CONNECTION is '短链接表';
comment
on column APPR_SHORT_CONNECTION.ID is '短链接表唯一id';
comment
on column APPR_SHORT_CONNECTION.URL is '真实请求url';
comment
on column APPR_SHORT_CONNECTION.PASSWORD is '短链接访问密码';
comment
on column APPR_SHORT_CONNECTION.STATUS is '状态：1：激活、2：过期:3：屏蔽:';
comment
on column APPR_SHORT_CONNECTION.TAG is '标签，用于分类';
comment
on column APPR_SHORT_CONNECTION.CREATE_TIME is '创建时间';
扫一扫
675
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
