使用redis鎖防止表單重複提交

模擬表單重複提交

使用Swagger調用接口

通過界面添加學生

分析

入庫時的驗重邏輯是入庫前先去數據庫查詢一次，沒有發現該條數據則入庫，這樣的操作並不是原子性的，會導致如果有兩條一樣的數據同時過來，同一時間查詢數據庫的話，會發現並沒有這條數據，這樣就會將這兩條一樣的數據同時入庫。因此，我們需要在入庫前加一把鎖，使得同時過來的同樣的數據只有一條能去進行查詢數據庫驗重這步操作。

使用redis分佈式鎖防止數據重複入庫

    /**
     * 學生保存
     * @param stu
     * @return
     */
    @Log("保存學生")
    @ApiOperation(value = "學生信息保存", notes = "將輸入的學生信息保存到數據庫")
    @PostMapping(value = "/save", produces = MediaType.APPLICATION_JSON_VALUE)
    @ResponseBody
    public ActionResult saveStudent(StudentDO stu){
        ActionResult result = new ActionResult();

        if(stu.getSno()==null){
            String lockKey = "student:phone:"+stu.getPhone();
            RLock lock = redissonClient.getLock(lockKey);
            boolean res = false;
            try {
                //獲取鎖等待超時時間爲5s,鎖租期爲60s
                res = lock.tryLock(5, 60, TimeUnit.SECONDS);
            } catch (Exception e) {
                logger.error(e.getMessage(), e);
            }
            if (!res) {
                logger.info("獲取鎖超時 res: {}", res);
                result.setStatus(-2);
                result.setMsg("該學生正在新增中，請稍後再試...");
                return result;
            }

            try {
                List<StudentDO> list = studentDOMapper.selectByPhone(stu.getPhone());
                if(list!=null&&list.size()>0){
                    result = ActionResult.build(-1, "手機號碼重複，添加失敗");
                    return result;
                }
                studentDOMapper.insert(stu);
            } finally {
                //超過leaseTime鎖自動釋放，導致unlock方法失效
                try {
                    if (lock.isHeldByCurrentThread() && lock.isLocked()) {
                        lock.unlock();
                        logger.info("釋放鎖");
                    }
                } catch (Exception e) {
                    logger.error(e.getMessage(), e);
                }
            }

        } else {
            List<StudentDO> list = studentDOMapper.selectByPhoneAndSno(stu.getPhone(), stu.getSno());
            if(list!=null&&list.size()>0){
                result = ActionResult.build(-1, "手機號碼重複，修改失敗");
                return result;
            }
            studentDOMapper.updateByPrimaryKey(stu);
        }
        result = ActionResult.ok(studentDOMapper.selectByPrimaryKey(stu.getSno()));
        return result;
    }

再次模擬表單重複提交

模擬表單重複提交的腳本

package com.yangzc.studentboot;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

/**
 * @Author: yangzc
 * @Description:
 * @Date: Created on 8:04 2020/6/9
 * @Modified By:
 */
public class StudentTest {
    public static void main(String[] args) {
        //創建可關閉的客戶端工具
        CloseableHttpClient c1 = HttpClients.createDefault();
        CloseableHttpClient c2 = HttpClients.createDefault();

        HttpPost r1 = new HttpPost("http://192.168.18.107:8080/stu/list/save");
        HttpPost r2 = new HttpPost("http://192.168.18.107:8080/stu/list/save");

        String data = "sno=&sname=%E5%BC%A0%E4%B8%89&gender=1&birth=2020-06-08&phone=17721038957&photoUrl=%2Fimg%2Fdefault.png";

        StringEntity requestEntity = new StringEntity(data,"utf-8");

        r1.addHeader("Content-type","application/x-www-form-urlencoded");
        r1.addHeader("Cookie","JSESSIONID=5010b0b0-1ee1-4448-9edf-b3abe3cd61b8");
        r1.setEntity(requestEntity);

        r2.addHeader("Content-type","application/x-www-form-urlencoded");
        r2.addHeader("Cookie","JSESSIONID=5010b0b0-1ee1-4448-9edf-b3abe3cd61b8");
        r2.setEntity(requestEntity);

        Thread t1 = new MyThread(c1,r1);
        Thread t2 = new MyThread(c2,r2);

        t1.start();
        t2.start();
        //c1.close();
        //c2.close();
        //System.out.println("Hello World!");
    }
}

package com.yangzc.studentboot;
import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.util.EntityUtils;
/**
 * @Author: yangzc
 * @Description:
 * @Date: Created on 8:08 2020/6/9
 * @Modified By:
 */
public class MyThread extends Thread {
    private CloseableHttpClient client;
    private HttpPost request;

    public MyThread(CloseableHttpClient client, HttpPost request) {
        this.client = client;
        this.request = request;
    }

    public void run(){
        try {
            HttpResponse response = client.execute(request);
            String text = EntityUtils.toString(response.getEntity());
            System.out.println(Thread.currentThread().getName()+": "+text);
            client.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

項目開源地址

https://github.com/yangzc23/studentboot

參考資料
[01] 使用Session防止表單重複提交
[02] JavaWeb防止表單重複提交的幾種方式
[03] Redisson基本用法
[04] redis客戶端redisson實戰
[05] HttpClient 4 使用POST方式提交普通表單數據的例子
[06] Redis分佈式鎖的實現原理
[07] 使用Redis分佈式鎖處理併發，解決超賣問題
[08] Redission分佈式鎖
[09] Bootstrap表單
[10] git 放棄本地修改，強制拉取更新
[11] Java使用Redis實現分佈式鎖來防止重複提交問題
[12] 利用redis分佈式鎖來防止數據重複入庫
[13] BootStrap Validator 版本差異問題導致的submitHandler失效問題的解決方法
[14] BootstrapValidator使用教程
[15] bootstrapvalidator實現校驗、校驗清除重置
[16] bootstrapvalidator校驗、校驗清除重置

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