网站宣传方案,开发专业网站,有哪些可以做1元夺宝的网站,聊城网站建设企业文章目录 工作原理需求实现1#xff09;自定义防重复提交注解2#xff09;定义防重复提交AOP切面3#xff09;RedisLock 工具类4#xff09;过滤器 请求工具类5#xff09;测试Controller6#xff09;测试结果 工作原理
分布式环境下#xff0c;可能会遇到用户对某个接… 文章目录 工作原理需求实现1自定义防重复提交注解2定义防重复提交AOP切面3RedisLock 工具类4过滤器 请求工具类5测试Controller6测试结果 工作原理
分布式环境下可能会遇到用户对某个接口被重复点击的场景为了防止接口重复提交造成的问题可用 Redis 实现一个简单的分布式锁来解决问题。
在 Redis 中 SETNX 命令是可以帮助我们实现互斥。SETNX 即 SET if Not eXists (对应 Java 中的 setIfAbsent 方法)如果 key 不存在的话才会设置 key 的值。如果 key 已经存在 SETNX 啥也不做。
需求实现
自定义一个防止重复提交的注解注解中可以携带到期时间和一个参数的key为需要防止重复提交的接口添加注解注解AOP会拦截加了此注解的请求进行加解锁处理并且添加注解上设置的key超时时间Redis 中的 key token - path - param_value; 例如17800000001 /api/subscribe/ zhangsan如果重复调用某个加了注解的接口且key还未到期就会返回重复提交的Result。
1自定义防重复提交注解
自定义防止重复提交注解注解中可设置 超时时间 要扫描的参数请求中的某个参数最终拼接后成为Redis中的key
package com.lihw.lihwtestboot.noRepeatSubmit;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/*** 防重复提交注解*/
Target(ElementType.METHOD)
Retention(RetentionPolicy.RUNTIME)
public interface NoRepeatSubmit {/*** 锁过期的时间*/int seconds() default 5;/*** 要扫描的参数*/String scanParam() default ;
}
2定义防重复提交AOP切面
Pointcut(annotation(noRepeatSubmit)) 表示切点表达式它使用了注解匹配的方式来选择被注解 NoRepeatSubmit 标记的方法。
package com.lihw.lihwtestboot.noRepeatSubmit;import com.alibaba.fastjson.JSONObject;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.UUID;
/*** 重复提交aop*/
Aspect
Component
public class RepeatSubmitAspect {private static final Logger LOGGER LoggerFactory.getLogger(RepeatSubmitAspect.class);Autowiredprivate RedisLock redisLock;Pointcut(annotation(noRepeatSubmit))public void pointCut(NoRepeatSubmit noRepeatSubmit) {}Around(pointCut(noRepeatSubmit))public Object around(ProceedingJoinPoint pjp, NoRepeatSubmit noRepeatSubmit) throws Throwable {//获取基本信息ServletRequestAttributes attributes (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();HttpServletRequest request attributes.getRequest();Assert.notNull(request, request can not null);int lockSeconds noRepeatSubmit.seconds();//过期时间String threadName Thread.currentThread().getName();// 获取当前线程名称String param noRepeatSubmit.scanParam();//请求参数String path request.getServletPath();String type request.getMethod();String param_value ;if (type.equals(POST)){param_value JSONObject.parseObject(new BodyReaderHttpServletRequestWrapper(request).getBodyString()).getString(param);}else if (type.equals(GET)){param_value request.getParameter(param);}String token request.getHeader(uid);LOGGER.info(线程{}, 接口{},重复提交验证,threadName,path);String key;if (!.equals(param) param ! null){key token - path - param_value;//生成key}else {key token - path;//生成key}String clientId getClientId();// 调接口时生成临时valueUUID// 用于添加锁如果添加成功返回true失败返回false boolean isSuccess redisLock.tryLock(key, clientId, lockSeconds);ApiResult result new ApiResult();if (isSuccess) {LOGGER.info(加锁成功接口 {}, key {}, path, key);// 获取锁成功Object obj;try {// 执行进程obj pjp.proceed();// aop代理链执行的方法} finally {// 据key从redis中获取valueif (clientId.equals(redisLock.get(key))) {// 解锁redisLock.releaseLock(key, clientId);LOGGER.info(解锁成功接口{}, key {},,path, key);}}return obj;} else {// 添加锁失败认为是重复提交的请求LOGGER.info(重复请求接口 {}, key {},path, key);result.setData(重复提交);return result;}}private String getClientId() {return UUID.randomUUID().toString();}public static String getRequestBodyData(HttpServletRequest request) throws IOException{BufferedReader bufferReader new BufferedReader(request.getReader());StringBuilder sb new StringBuilder();String line null;while ((line bufferReader.readLine()) ! null) {sb.append(line);}return sb.toString();}
}3RedisLock 工具类
package com.lihw.lihwtestboot.noRepeatSubmit;import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import java.util.concurrent.TimeUnit;Service
public class RedisLock {private static final Logger logger LoggerFactory.getLogger(RedisLock.class);/** 不设置过期时长 */public final static long NOT_EXPIRE -1;Autowiredprivate StringRedisTemplate redisTemplate;/*** param lockKey 加锁键* param clientId 加锁客户端唯一标识(采用UUID)* param seconds 锁过期时间* return*/public boolean tryLock(String lockKey, String clientId, long seconds) {if (redisTemplate.opsForValue().setIfAbsent(lockKey, clientId,seconds, TimeUnit.SECONDS)) {return true;//得到锁}else{return false;}}/*** 与 tryLock 相对应用作释放锁** param lockKey* param clientId* return*/public boolean releaseLock(String lockKey, String clientId) {String currentValue redisTemplate.opsForValue().get(lockKey);try {if (!StringUtils.isEmpty(currentValue) currentValue.equals(clientId)) {redisTemplate.opsForValue().getOperations().delete(lockKey);return true;}else {return false;}} catch (Exception e) {logger.error(解锁异常{} , e);return false;}}/*** 获取* param key* return*/public String get(String key) {return get(key, NOT_EXPIRE);}public String get(String key, long expire) {String value redisTemplate.opsForValue().get(key);if(expire ! NOT_EXPIRE){redisTemplate.expire(key, expire, TimeUnit.SECONDS);}return value;}/*** 删除* param key*/public void delete(String key) {redisTemplate.delete(key);}
}4过滤器 请求工具类
Filter类
package com.lihw.lihwtestboot.noRepeatSubmit;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.servlet.ServletComponentScan;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;ServletComponentScan
WebFilter(urlPatterns /*,filterName channelFilter)
public class ChannelFilter implements Filter {private final Logger logger LoggerFactory.getLogger(this.getClass());Overridepublic void init(FilterConfig filterConfig) throws ServletException {}Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {logger.info(-----------------------Execute filter start---------------------);// 防止流读取一次后就没有了, 所以需要将流继续写出去HttpServletRequest httpServletRequest (HttpServletRequest) servletRequest;ServletRequest requestWrapper new BodyReaderHttpServletRequestWrapper(httpServletRequest);filterChain.doFilter(requestWrapper, servletResponse);}}
BodyReaderHttpServletRequestWrapper
对GET和POST请求的获取参数方法进行了封装
package com.lihw.lihwtestboot.noRepeatSubmit;import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper{/*** Request请求参数获取处理类*/private final byte[] body;public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {super(request);String sessionStream getBodyString(request);body sessionStream.getBytes(StandardCharsets.UTF_8);}/*** 获取请求Body** param request* return*/private String getBodyString(final ServletRequest request) {StringBuilder sb new StringBuilder();InputStream inputStream null;BufferedReader reader null;try {inputStream cloneInputStream(request.getInputStream());reader new BufferedReader(new InputStreamReader(inputStream, Charset.forName(UTF-8)));String line ;while ((line reader.readLine()) ! null) {sb.append(line);}} catch (IOException e) {e.printStackTrace();} finally {if (inputStream ! null) {try {inputStream.close();} catch (IOException e) {e.printStackTrace();}}if (reader ! null) {try {reader.close();} catch (IOException e) {e.printStackTrace();}}}return sb.toString();}public String getBodyString() {return new String(body, StandardCharsets.UTF_8);}/*** Description: 复制输入流** param inputStream* return*/public InputStream cloneInputStream(ServletInputStream inputStream) {ByteArrayOutputStream byteArrayOutputStream new ByteArrayOutputStream();byte[] buffer new byte[1024];int len;try {while ((len inputStream.read(buffer)) -1) {byteArrayOutputStream.write(buffer, 0, len);}byteArrayOutputStream.flush();} catch (IOException e) {e.printStackTrace();}InputStream byteArrayInputStream new ByteArrayInputStream(byteArrayOutputStream.toByteArray());return byteArrayInputStream;}Overridepublic BufferedReader getReader() throws IOException {return new BufferedReader(new InputStreamReader(getInputStream()));}Overridepublic ServletInputStream getInputStream() throws IOException {final ByteArrayInputStream bais new ByteArrayInputStream(body);return new ServletInputStream() {Overridepublic int read() throws IOException {return bais.read();}Overridepublic boolean isFinished() {return false;}Overridepublic boolean isReady() {return false;}Overridepublic void setReadListener(ReadListener readListener) {}};}
}
5测试Controller
package com.lihw.lihwtestboot.noRepeatSubmit;import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
import javax.validation.constraints.NotEmpty;RestController
RequestMapping(/api)
Validated
public class noRepeatSubmitController {GetMapping(/subscribe/{channel})NoRepeatSubmit(seconds 10,scanParam username)public ApiResult subscribe(RequestHeader(name uid) String phone,RequestHeader(name username) String username,PathVariable(channel) NotEmpty(message channel不能为空) String channel) {System.out.println(phone phone);System.out.println(username username);System.out.println(channel channel);try {Thread.sleep(5000);//模拟耗时} catch (InterruptedException e) {e.printStackTrace();}return new ApiResult(success,data);}
}
6测试结果 重复点击
