chore[litemall-db]: 写一个乐观锁更新的测试用例

litemall-db/src/test/java/org/linlinjava/litemall/db/OptimisticLockTest.java

+package org.linlinjava.litemall.db;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.linlinjava.litemall.db.dao.LitemallSystemMapper;
+import org.linlinjava.litemall.db.domain.LitemallSystem;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+
+/*
+   main线程先select，然后睡眠1s，最后做update
+   another线程则是先select，然后做update
+
+   main:        select                           update 2
+   another:               select     update 3
+
+   如果没有乐观锁，那么最后main线程的update操作是成功的，最终数据库保存的值是2；
+   如果设置乐观锁，那么最后main线程的update操作是失败的，最终数据库保存的值是3。
+
+   在一些业务过程中，需要采用乐观锁，这样可以保证数据更新时不会出现问题。
+ */
+@WebAppConfiguration
+@RunWith(SpringJUnit4ClassRunner.class)
+@SpringBootTest
+public class OptimisticLockTest {
+
+    @Autowired
+    private LitemallSystemMapper systemMapper;
+
+    private Integer unlockId;
+    private Integer lockId;
+
+    @Before
+    public void before() {
+        LitemallSystem unlockSystemConfig = new LitemallSystem();
+        unlockSystemConfig.setKeyName("test-unlocksystem-key");
+        unlockSystemConfig.setKeyValue("test-unlocksystem-value-1");
+        systemMapper.insertSelective(unlockSystemConfig);
+        unlockId = unlockSystemConfig.getId();
+
+        LitemallSystem lockSystemConfig = new LitemallSystem();
+        lockSystemConfig.setKeyName("test-locksystem-key");
+        lockSystemConfig.setKeyValue("test-locksystem-value-1");
+        systemMapper.insertSelective(lockSystemConfig);
+        lockId = lockSystemConfig.getId();
+    }
+
+    @After
+    public void after() {
+        systemMapper.deleteByPrimaryKey(unlockId);
+        unlockId = null;
+        systemMapper.deleteByPrimaryKey(lockId);
+        lockId = null;
+    }
+
+
+    @Test
+    public void runWithOptimisticLock() {
+        LitemallSystem mainSystem = systemMapper.selectByPrimaryKey(lockId);
+
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                LitemallSystem anotherSystem = systemMapper.selectByPrimaryKey(lockId);
+
+                anotherSystem.setKeyValue("test-locksystem-value-3");
+                systemMapper.updateWithVersionByPrimaryKey(anotherSystem.getVersion(), anotherSystem);
+            }
+        }).start();
+
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+        mainSystem.setKeyValue("test-locksystem-value-2");
+        int updates = systemMapper.updateWithVersionByPrimaryKey(mainSystem.getVersion(), mainSystem);
+        Assert.assertEquals(updates, 0);
+
+        mainSystem = systemMapper.selectByPrimaryKey(lockId);
+        Assert.assertNotEquals(mainSystem.getKeyValue(), "test-locksystem-value-2");
+        Assert.assertEquals(mainSystem.getKeyValue(), "test-locksystem-value-3");
+    }
+
+    @Test
+    public void runWithoutOptimisticLock() {
+        LitemallSystem mainSystem = systemMapper.selectByPrimaryKey(unlockId);
+
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                LitemallSystem anotherSystem = systemMapper.selectByPrimaryKey(unlockId);
+
+                anotherSystem.setKeyValue("test-unlocksystem-value-3");
+                systemMapper.updateByPrimaryKey(anotherSystem);
+            }
+        }).start();
+
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+        mainSystem.setKeyValue("test-unlocksystem-value-2");
+        int updates = systemMapper.updateByPrimaryKey(mainSystem);
+        Assert.assertEquals(updates, 1);
+
+        mainSystem = systemMapper.selectByPrimaryKey(unlockId);
+        Assert.assertEquals(mainSystem.getKeyValue(), "test-unlocksystem-value-2");
+        Assert.assertNotEquals(mainSystem.getKeyValue(), "test-unlocksystem-value-3");
+    }
+}
+