使用redis 实现分布式锁，处理并发问题

处理逻辑，为了防止同一个订单，产生并发的问题，这里设置了一个锁，向redis 中加入以订单号为key的键值对，

每次执行订单处理时，会先判断redis 缓存中是否有这个key,

已存在的话，就挂起一段之间，重试5次，

如果在业务逻辑处理完，会删除redis 中的关于该订单的数据

import java.util.ArrayList;import java.util.List;import java.util.Set;import org.apache.commons.collections.CollectionUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import com.suning.fsp.common.exception.AppException;/** * 一个接一个业务处理模版默认实现<br> *  * <p> * 用一个业务处理表记录，在处理前对锁状态进行判断 ，判断逻辑参见{@link #beforeInvoke}方法<br> *  * 业务处理表： 业务类型 PK|业务ID PK|方法|创建时间<br> *  *  */@Service("redisOneByOneTemplate")public class RedisOneByOneTemplateImpl implements RedisOneByOneTemplate {     /** 业务正在处理中 */    public static final String ERROR_BIZ_PROCESSING = "error.biz.processing";    /** logger */    private static final Logger LOGGER = LoggerFactory.getLogger(RedisOneByOneTemplateImpl.class);        private static final String CACHE_PREFIX_KEY = "EPP:FSP:ONEBYONE:CACHE:";        private static final Long REDIS_OPT_RES_FAIL = 0L;        /**     * 并发时循环等待的最大次数     */    private static final int REPEAT_MAX_COUNT = 5;    @Autowired    RedisOneByOneCacheDao redisOneByOneCacheDao;    /**     * {@inheritDoc}     */    public <T> T execute(OneByOne oneByOne, CallBack<T> callBack) {        oneByOne.setDescription(oneByOne.getBizType() + "-" + oneByOne.getBizId() + "-" + oneByOne.getMethod());        try {            this.beforeInvoke(oneByOne);            return callBack.invoke();        } finally {            this.afterInvoke(oneByOne);        }    }        /**     * 查询所有的存在的OneByOne锁     * @return OneByOne锁列表     */    @Override    public List<String> queryAllOneByOne() {    Set<String> values = redisOneByOneCacheDao.smembers(CACHE_PREFIX_KEY);    return new ArrayList<String>(values);    }        /**     * 清除所有的OneByOne锁     */    @Override    public void clearOneByOne(List<String> values) {    if (CollectionUtils.isNotEmpty(values)) {    for (String value : values) {    redisOneByOneCacheDao.srem(CACHE_PREFIX_KEY, value);    }    }    }    /**     * 回调前置     *      * @param oneByOne 一个接一个处理记录     */    private void beforeInvoke(final OneByOne oneByOne) {    int count = 0;        do {         try {        oneByOne.setInsertSuccess(true);                // 插入处理记录        Long addRes = redisOneByOneCacheDao.sadd(CACHE_PREFIX_KEY,         oneByOne.getBizType() + "|" + oneByOne.getBizId());        if (REDIS_OPT_RES_FAIL == addRes) {        oneByOne.setInsertSuccess(false);        LOGGER.info(oneByOne.getDescription() + "插入处理记录发生错误！");        }                 } catch (Throwable t) {        oneByOne.setInsertSuccess(false);                LOGGER.error(oneByOne.getDescription() + "插入处理记录发生异常！t:{}", t);        }                if (!oneByOne.isInsertSuccess()) {                LOGGER.info(oneByOne.getDescription() + "插入处理记录失败！");                // 重试次数累加        count++;        if (count >= REPEAT_MAX_COUNT) {        // 如果插入失败，抛出AppException        throw new AppException(ERROR_BIZ_PROCESSING, oneByOne.getDescription() + "业务正在处理中");        }                // 等待一段时间        try {        // 每次等待时间拉长        Thread.sleep(2000);} catch (InterruptedException e) {        LOGGER.info(oneByOne.getDescription() + " occur InterruptedException while wait.");}        }        }        while (!oneByOne.isInsertSuccess());            }    /**     * 回调后置     *      * @param oneByOne 一个接一个处理记录     */    private void afterInvoke(final OneByOne oneByOne) {        // 插入失败，不删除处理记录        if (!oneByOne.isInsertSuccess()) {            return;        }        try {        // 删除处理记录        Long res = redisOneByOneCacheDao.srem(CACHE_PREFIX_KEY,         oneByOne.getBizType() + "|" + oneByOne.getBizId());        if (res > 0) {        LOGGER.debug("Remove oneByOne success, the bizType is: {}, the bizId is: {}",         oneByOne.getBizType(), oneByOne.getBizId());        } else {        LOGGER.debug("No value exist in redis, the bizType is: {}, the bizId is: {}",         oneByOne.getBizType(), oneByOne.getBizId());        }                } catch (Throwable t) {            LOGGER.error(oneByOne.getDescription() + "删除处理记录失败！t:{}", t);        }    }}

callback 接口

public interface CallBack<T> {    /**     * 调用     * @return 结果     */    T invoke();    }

oneByone类

public class OneByOne {    /** 业务类型 */    private String bizType;    /** 业务ID */    private String bizId;    /** 方法 */    private String method;    /** 创建时间 */    private Date createTime;    private String description;    private boolean insertSuccess;        /**     * 同时最大等待执行的个数（默认为10个）     */    private int maxWaitCount = 10;    /**     * 创建一个接一个处理记录     *      * @param bizType 业务类型     * @param bizId 业务ID     * @param method 方法     */    public OneByOne(String bizType, String bizId, String method) {        this.bizType = bizType;        this.bizId = bizId;        this.method = method;    }        /**     * 创建一个接一个处理记录     *      * @param bizType 业务类型     * @param bizId 业务ID     * @param method 方法     * @param maxWaitCount 最大等待数     */    public OneByOne(String bizType, String bizId, String method, int maxWaitCount) {        this.bizType = bizType;        this.bizId = bizId;        this.method = method;        this.setMaxWaitCount(maxWaitCount);    }    /**     * 获取业务类型     *      * @return 业务类型     */    public String getBizType() {        return bizType;    }    /**     * 设置业务类型     *      * @param bizType 业务类型     */    public void setBizType(String bizType) {        this.bizType = bizType;    }    /**     * 获取业务ID     *      * @return 业务ID     */    public String getBizId() {        return bizId;    }    /**     * 设置业务ID     *      * @param bizId 业务ID     */    public void setBizId(String bizId) {        this.bizId = bizId;    }    /**     * 获取方法     *      * @return 方法     */    public String getMethod() {        return method;    }    /**     * 设置方法     *      * @param method 方法     */    public void setMethod(String method) {        this.method = method;    }    /**     * 获取创建时间     *      * @return 创建时间     */    public Date getCreateTime() {        return createTime;    }    /**     * 设置创建时间     *      * @param createTime 创建时间     */    public void setCreateTime(Date createTime) {        this.createTime = createTime;    }    /**     * @return the description     */    String getDescription() {        return description;    }    /**     * @param description the description to set     */    void setDescription(String description) {        this.description = description;    }    /**     * @return the insertSuccess     */    boolean isInsertSuccess() {        return insertSuccess;    }    /**     * @param insertSuccess the insertSuccess to set     */    void setInsertSuccess(boolean insertSuccess) {        this.insertSuccess = insertSuccess;    }public void setMaxWaitCount(int maxWaitCount) {this.maxWaitCount = maxWaitCount;}public int getMaxWaitCount() {return maxWaitCount;}}