SpringCloud微服务实战——搭建企业级开发框架（三十九）：使用Redis分布式锁（Redisson）+自定义注解+AOP实现微服务重复请求控制

package com.gitegg.platform.base.annotation.resubmit;
import java.lang.annotation.*;
import java.util.concurrent.TimeUnit;
/**
 * 防止重复提交注解
 * 1、当设置了keys时，通过表达式确定取哪几个参数作为防重key
 * 2、当未设置keys时，可以设置argsIndex设置取哪几个参数作为防重key
 * 3、argsIndex和ignoreKeys是未设置keys时生效，排除不需要防重的参数
 * 4、因部分浏览器在跨域请求时，不允许request请求携带cookie，导致每次sessionId都是新的，所以这里默认使用用户id作为key的一部分，不使用sessionId
 * @author GitEgg
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ResubmitLock {
    /**
     * 防重复提交校验的时间间隔
     */
    long interval() default 5;
    /**
     * 防重复提交校验的时间间隔的单位
     */
    TimeUnit timeUnit() default TimeUnit.SECONDS;
    /**
     * 是否仅在当前session内进行防重复提交校验
     */
    boolean currentSession() default false;
    /**
     * 是否选用当前操作用户的信息作为防重复提交校验key的一部分
     */
    boolean currentUser() default true;
    /**
     * keys和ignoreKeys不能同时使用
     * 参数Spring EL表达式例如 #{param.name},表达式的值作为防重复校验key的一部分
     */
    String[] keys() default {};
    /**
     * keys和ignoreKeys不能同时使用
     * ignoreKeys不区分入参，所有入参拥有相同的字段时，都将过滤掉
     */
    String[] ignoreKeys() default {};
    /**
     * Spring EL表达式,决定是否进行重复提交校验,多个条件之间为且的关系,默认是进行校验
     */
    String[] conditions() default {"true"};
    /**
     * 当未配置key时，设置哪几个参数作为防重对象，默认取所有参数
     *
     * @return
     */
    int[] argsIndex() default {};
}

package com.gitegg.platform.boot.aspect;
import com.gitegg.platform.base.annotation.resubmit.ResubmitLock;
import com.gitegg.platform.base.enums.ResultCodeEnum;
import com.gitegg.platform.base.exception.SystemException;
import com.gitegg.platform.base.util.JsonUtils;
import com.gitegg.platform.boot.util.ExpressionUtils;
import com.gitegg.platform.boot.util.GitEggAuthUtils;
import com.gitegg.platform.boot.util.GitEggWebUtils;
import com.gitegg.platform.redis.lock.IDistributedLockService;
import com.google.common.collect.Maps;
import lombok.RequiredArgsConstructor;
import lombok.extern.log4j.Log4j2;
import org.apache.commons.lang3.ArrayUtils;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.lang.NonNull;
import org.springframework.stereotype.Component;
import org.springframework.util.DigestUtils;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Map;
import java.util.TreeMap;
/**
 * @author GitEgg
 * @date 2022-4-10
 */
@Log4j2
@Component
@Aspect
@RequiredArgsConstructor(onConstructor_ = @Autowired)
@ConditionalOnProperty(name = "enabled", prefix = "resubmit-lock", havingValue = "true", matchIfMissing = true)
public class ResubmitLockAspect {
    private static final String REDIS_SEPARATOR = ":";
    private static final String RESUBMIT_CHECK_KEY_PREFIX = "resubmit_lock" + REDIS_SEPARATOR;
    private final IDistributedLockService distributedLockService;
    /**
     * Before切点
     */
    @Pointcut("@annotation(com.gitegg.platform.base.annotation.resubmit.ResubmitLock)")
    public void resubmitLock() {
    }
    /**
     * 前置通知 防止重复提交
     *
     * @param joinPoint 切点
     * @param resubmitLock 注解配置
     */
    @Before("@annotation(resubmitLock)")
    public Object resubmitCheck(JoinPoint joinPoint, ResubmitLock resubmitLock) throws Throwable {
        final Object[] args = joinPoint.getArgs();
        final String[] conditions = resubmitLock.conditions();
        //根据条件判断是否需要进行防重复提交检查
        if (!ExpressionUtils.getConditionValue(args, conditions) || ArrayUtils.isEmpty(args)) {
            return ((ProceedingJoinPoint) joinPoint).proceed();
        }
        doCheck(resubmitLock, args);
        return ((ProceedingJoinPoint) joinPoint).proceed();
    }
    /**
     * key的组成为: resubmit_lock:userId:sessionId:uri:method:(根据spring EL表达式对参数进行拼接)
     *
     * @param resubmitLock 注解
     * @param args       方法入参
     */
    private void doCheck(@NonNull ResubmitLock resubmitLock, Object[] args) {
        final String[] keys = resubmitLock.keys();
        final boolean currentUser = resubmitLock.currentUser();
        final boolean currentSession = resubmitLock.currentSession();
        String method = GitEggWebUtils.getRequest().getMethod();
        String uri = GitEggWebUtils.getRequest().getRequestURI();
        StringBuffer lockKeyBuffer = new StringBuffer(RESUBMIT_CHECK_KEY_PREFIX);
        if (null != GitEggAuthUtils.getTenantId())
        {
            lockKeyBuffer.append( GitEggAuthUtils.getTenantId()).append(REDIS_SEPARATOR);
        }
        // 此判断暂时预留，适配后续无用户登录场景，因部分浏览器在跨域请求时，不允许request请求携带cookie，导致每次sessionId都是新的，所以这里默认使用用户id作为key的一部分，不使用sessionId
        if (currentSession)
        {
            lockKeyBuffer.append( GitEggWebUtils.getSessionId()).append(REDIS_SEPARATOR);
        }
        // 默认没有将user数据作为防重key
        if (currentUser && null != GitEggAuthUtils.getCurrentUser())
        {
            lockKeyBuffer.append( GitEggAuthUtils.getCurrentUser().getId() ).append(REDIS_SEPARATOR);
        }
        lockKeyBuffer.append(uri).append(REDIS_SEPARATOR).append(method);
        StringBuffer parametersBuffer = new StringBuffer();
        // 优先判断是否设置防重字段，因keys试数组，取值时是按照顺序排列的，这里不需要重新排序
        if (ArrayUtils.isNotEmpty(keys))
        {
            Object[] argsForKey = ExpressionUtils.getExpressionValue(args, keys);
            for (Object obj : argsForKey) {
                parametersBuffer.append(REDIS_SEPARATOR).append(String.valueOf(obj));
            }
        }
        // 如果没有设置防重的字段，那么需要把所有的字段和值作为key，因通过反射获取字段时，顺序时不确定的，这里取出来之后需要进行排序
        else{
            // 只有当keys为空时，ignoreKeys和argsIndex生效
            final String[] ignoreKeys = resubmitLock.ignoreKeys();
            final int[] argsIndex = resubmitLock.argsIndex();
            if (ArrayUtils.isNotEmpty(argsIndex))
            {
                for(int index : argsIndex){
                    parametersBuffer.append(REDIS_SEPARATOR).append( getKeyAndValueJsonStr(args[index], ignoreKeys));
                }
            }
            else
            {
                for(Object obj : args){
                    parametersBuffer.append(REDIS_SEPARATOR).append( getKeyAndValueJsonStr(obj, ignoreKeys) );
                }
            }
        }
        // 将请求参数取md5值作为key的一部分，MD5理论上会重复，但是key中还包含session或者用户id，所以同用户在极端时间内请参数不同生成的相同md5值的概率极低
        String parametersKey = DigestUtils.md5DigestAsHex(parametersBuffer.toString().getBytes());
        lockKeyBuffer.append(parametersKey);
        try {
            boolean isLock = distributedLockService.tryLock(lockKeyBuffer.toString(), 0, resubmitLock.interval(), resubmitLock.timeUnit());
            if (!isLock)
            {
                throw new SystemException(ResultCodeEnum.RESUBMIT_LOCK.code, ResultCodeEnum.RESUBMIT_LOCK.msg);
            }
        } catch (InterruptedException e) {
            throw new SystemException(ResultCodeEnum.RESUBMIT_LOCK.code, ResultCodeEnum.RESUBMIT_LOCK.msg);
        }
    }
    /**
     * 将字段转换为json字符串
     * @param obj
     * @return
     */
    public static String getKeyAndValueJsonStr(Object obj, String[] ignoreKeys) {
        Map<String, Object> map = Maps.newHashMap();
        // 得到类对象
        Class objCla = (Class) obj.getClass();
        /* 得到类中的所有属性集合 */
        Field[] fs = objCla.getDeclaredFields();
        for (int i = 0; i < fs.length; i++) {
            Field f = fs[i];
            // 设置些属性是可以访问的
            f.setAccessible(true);
            Object val = new Object();
            try {
                String filedName = f.getName();
                // 如果字段在排除列表，那么不将字段放入map
                if (null != ignoreKeys && Arrays.asList(ignoreKeys).contains(filedName))
                {
                    continue;
                }
                val = f.get(obj);
                // 得到此属性的值
                // 设置键值
                map.put(filedName, val);
            } catch (IllegalArgumentException e) {
                log.error("getKeyAndValue IllegalArgumentException", e);
                throw new RuntimeException("您的操作太频繁，请稍后再试");
            } catch (IllegalAccessException e) {
                log.error("getKeyAndValue IllegalAccessException", e);
                throw new RuntimeException("您的操作太频繁，请稍后再试");
            }
        }
        Map<String, Object> sortMap = sortMapByKey(map);
        String mapStr = JsonUtils.mapToJson(sortMap);
        return mapStr;
    }
    private static Map<String, Object> sortMapByKey(Map<String, Object> map) {
        if (map == null || map.isEmpty()) {
            return null;
        }
        Map<String, Object> sortMap = new TreeMap<String, Object>(new Comparator<String>() {
            @Override
            public int compare(String o1,String o2) {
                return ((String)o1).compareTo((String) o2);
            }
        });
        sortMap.putAll(map);
        return sortMap;
    }
}

package com.gitegg.platform.redis.lock;
import java.util.concurrent.TimeUnit;
/**
 * 分布式锁接口
 * @author GitEgg
 * @date 2022-4-10
 */
public interface IDistributedLockService {
    /**
     * 加锁
     * @param lockKey key
     */
    void lock(String lockKey);
    /**
     * 释放锁
     *
     * @param lockKey key
     */
    void unlock(String lockKey);
    /**
     * 加锁并设置有效期
     *
     * @param lockKey key
     * @param timeout 有效时间，默认时间单位在实现类传入
     */
    void lock(String lockKey, int timeout);
    /**
     * 加锁并设置有效期指定时间单位
     * @param lockKey key
     * @param timeout 有效时间
     * @param unit    时间单位
     */
    void lock(String lockKey, int timeout, TimeUnit unit);
    /**
     * 尝试获取锁，获取到则持有该锁返回true,未获取到立即返回false
     * @param lockKey
     * @return true-获取锁成功 false-获取锁失败
     */
    boolean tryLock(String lockKey);
    /**
     * 尝试获取锁，获取到则持有该锁leaseTime时间.
     * 若未获取到，在waitTime时间内一直尝试获取，超过watiTime还未获取到则返回false
     * @param lockKey   key
     * @param waitTime  尝试获取时间
     * @param leaseTime 锁持有时间
     * @param unit      时间单位
     * @return true-获取锁成功 false-获取锁失败
     * @throws InterruptedException
     */
    boolean tryLock(String lockKey, long waitTime, long leaseTime, TimeUnit unit)
            throws InterruptedException;
    /**
     * 锁是否被任意一个线程锁持有
     * @param lockKey
     * @return true-被锁 false-未被锁
     */
    boolean isLocked(String lockKey);
}

package com.gitegg.platform.redis.lock.impl;
import com.gitegg.platform.redis.lock.IDistributedLockService;
import lombok.RequiredArgsConstructor;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.concurrent.TimeUnit;
/**
 * 分布式锁的 Redisson 接口实现
 * @author GitEgg
 * @date 2022-4-10
 */
@Service
@RequiredArgsConstructor(onConstructor_ = @Autowired)
public class DistributedLockServiceImpl implements IDistributedLockService {
    private final RedissonClient redissonClient;
    @Override
    public void lock(String lockKey) {
        RLock lock = redissonClient.getLock(lockKey);
        lock.lock();
    }
    @Override
    public void unlock(String lockKey) {
        RLock lock = redissonClient.getLock(lockKey);
        lock.unlock();
    }
    @Override
    public void lock(String lockKey, int timeout) {
        RLock lock = redissonClient.getLock(lockKey);
        lock.lock(timeout, TimeUnit.MILLISECONDS);
    }
    @Override
    public void lock(String lockKey, int timeout, TimeUnit unit) {
        RLock lock = redissonClient.getLock(lockKey);
        lock.lock(timeout, unit);
    }
    @Override
    public boolean tryLock(String lockKey) {
        RLock lock = redissonClient.getLock(lockKey);
        return lock.tryLock();
    }
    @Override
    public boolean tryLock(String lockKey, long waitTime, long leaseTime, TimeUnit unit) throws InterruptedException {
        RLock lock = redissonClient.getLock(lockKey);
        return lock.tryLock(waitTime, leaseTime, unit);
    }
    @Override
    public boolean isLocked(String lockKey) {
        RLock lock = redissonClient.getLock(lockKey);
        return lock.isLocked();
    }
}

package com.gitegg.platform.boot.util;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.expression.Expression;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.lang.NonNull;
import org.springframework.lang.Nullable;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
 * Spring Expression 工具类
 * @author GitEgg
 * @date 2022-4-11
 */
public class ExpressionUtils {
    private static final Map<String, Expression> EXPRESSION_CACHE = new ConcurrentHashMap<>(64);
    /**
     * 获取Expression对象
     *
     * @param expressionString Spring EL 表达式字符串 例如 #{param.id}
     * @return Expression
     */
    @Nullable
    public static Expression getExpression(@Nullable String expressionString) {
        if (StringUtils.isBlank(expressionString)) {
            return null;
        }
        if (EXPRESSION_CACHE.containsKey(expressionString)) {
            return EXPRESSION_CACHE.get(expressionString);
        }
        Expression expression = new SpelExpressionParser().parseExpression(expressionString);
        EXPRESSION_CACHE.put(expressionString, expression);
        return expression;
    }
    /**
     * 根据Spring EL表达式字符串从根对象中求值
     *
     * @param root             根对象
     * @param expressionString Spring EL表达式
     * @param clazz            值得类型
     * @param <T>              泛型
     * @return 值
     */
    @Nullable
    public static <T> T getExpressionValue(@Nullable Object root, @Nullable String expressionString, @NonNull Class<? extends T> clazz) {
        if (root == null) {
            return null;
        }
        Expression expression = getExpression(expressionString);
        if (expression == null) {
            return null;
        }
        return expression.getValue(root, clazz);
    }
    @Nullable
    public static <T> T getExpressionValue(@Nullable Object root, @Nullable String expressionString) {
        if (root == null) {
            return null;
        }
        Expression expression = getExpression(expressionString);
        if (expression == null) {
            return null;
        }
        //noinspection unchecked
        return (T) expression.getValue(root);
    }
    /**
     * 求值
     *
     * @param root              根对象
     * @param expressionStrings Spring EL表达式
     * @param <T>               泛型 这里的泛型要慎用,大多数情况下要使用Object接收避免出现转换异常
     * @return 结果集
     */
    public static <T> T[] getExpressionValue(@Nullable Object root, @Nullable String... expressionStrings) {
        if (root == null) {
            return null;
        }
        if (ArrayUtils.isEmpty(expressionStrings)) {
            return null;
        }
        //noinspection ConstantConditions
        Object[] values = new Object[expressionStrings.length];
        for (int i = 0; i < expressionStrings.length; i++) {
            //noinspection unchecked
            values[i] = (T) getExpressionValue(root, expressionStrings[i]);
        }
        //noinspection unchecked
        return (T[]) values;
    }
    /**
     * 表达式条件求值
     * 如果为值为null则返回false,
     * 如果为布尔类型直接返回,
     * 如果为数字类型则判断是否大于0
     *
     * @param root             根对象
     * @param expressionString Spring EL表达式
     * @return 值
     */
    @Nullable
    public static boolean getConditionValue(@Nullable Object root, @Nullable String expressionString) {
        Object value = getExpressionValue(root, expressionString);
        if (value == null) {
            return false;
        }
        if (value instanceof Boolean) {
            return (boolean) value;
        }
        if (value instanceof Number) {
            return ((Number) value).longValue() > 0;
        }
        return true;
    }
    /**
     * 表达式条件求值
     *
     * @param root              根对象
     * @param expressionStrings Spring EL表达式数组
     * @return 值
     */
    @Nullable
    public static boolean getConditionValue(@Nullable Object root, @Nullable String... expressionStrings) {
        if (root == null) {
            return false;
        }
        if (ArrayUtils.isEmpty(expressionStrings)) {
            return false;
        }
        //noinspection ConstantConditions
        for (String expressionString : expressionStrings) {
            if (!getConditionValue(root, expressionString)) {
                return false;
            }
        }
        return true;
    }
}

@ResubmitLock(interval = 30, keys = {"[0].realName","[0].mobile","[1].size"})
    public PageResult<UserInfo> list(@ApiIgnore QueryUserDTO user, @ApiIgnore Page<UserInfo> page) {
        Page<UserInfo> pageUser = userService.selectUserList(page, user);
        PageResult<UserInfo> pageResult = new PageResult<>(pageUser.getTotal(), pageUser.getRecords());
        return pageResult;
    }

@ResubmitLock(interval = 30, argsIndex = {0}, ignoreKeys = {"email","status"})
    public PageResult<UserInfo> list(@ApiIgnore QueryUserDTO user, @ApiIgnore Page<UserInfo> page) {
        Page<UserInfo> pageUser = userService.selectUserList(page, user);
        PageResult<UserInfo> pageResult = new PageResult<>(pageUser.getTotal(), pageUser.getRecords());
        return pageResult;
    }