添加事务使用实例

spring-boot/100-transaction-manager/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>spring-boot</artifactId>
+        <groupId>com.git.hui.boot</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>transaction-manager</artifactId>
+
+    <properties>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-jdbc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+        </dependency>
+    </dependencies>
+</project>

spring-boot/100-transaction-manager/src/main/java/com/git/hui/boot/trans/Application.java

@@ -0,0 +1,46 @@
+package com.git.hui.boot.trans;
+
+import com.git.hui.boot.trans.service.DemoService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * @author YiHui
+ * @date 2023/6/14
+ */
+@RestController
+@SpringBootApplication
+public class Application {
+    @Autowired
+    private DemoService demoService;
+
+    @GetMapping(path = "/")
+    public String preExecute() {
+        try {
+            demoService.transExecute(true);
+        } catch (Exception e) {
+            e.printStackTrace();
+            return e.getMessage();
+        }
+        return "ok";
+    }
+
+    @GetMapping(path = "/out")
+    public String outExecute() {
+        try {
+            demoService.outTransExecute();
+        } catch (Exception e) {
+            e.printStackTrace();
+            return e.getMessage();
+        }
+        return "ok";
+    }
+
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class);
+    }
+}

spring-boot/100-transaction-manager/src/main/java/com/git/hui/boot/trans/service/DemoService.java

@@ -0,0 +1,104 @@
+package com.git.hui.boot.trans.service;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+import org.springframework.util.Assert;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * @author YiHui
+ * @date 2023/6/14
+ */
+@Slf4j
+@Service
+public class DemoService {
+    @Autowired
+    private JdbcTemplate jdbcTemplate;
+
+    private ThreadLocal<String> cache = new ThreadLocal<>();
+    private AtomicInteger cnt = new AtomicInteger(1);
+
+    @Autowired
+    private DemoService demoService;
+
+    @Transactional(rollbackFor = Exception.class)
+    public void outTransExecute() throws InterruptedException {
+        String name = "2灰灰" + cnt.getAndAdd(1);
+        log.info("{}-out写入缓存: {}", Thread.currentThread(), name);
+        jdbcTemplate.execute("insert into money (`name`, `money`) values ('" + name + "', " + cnt.get() + ");");
+
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                demoService.transExecute(false);
+            }
+        }).start();
+
+        // 验证外部事务回滚，子线程的事务是否也会回滚（判断两个事务是否是同一个）
+        log.info("外部执行完毕!");
+        Thread.sleep(2000);
+        Assert.isTrue(Math.random() > 0.5, "外部事务回滚");
+    }
+
+    /**
+     * 事务提交前执行某些操作
+     * - 再同一个线程中执行，不过注册的事务提交前执行任务，会后置到这个方法执行完，再然后在相同的线程中执行
+     */
+    @Transactional(rollbackFor = Exception.class)
+    public void transExecute(boolean hasException) {
+        String name = "一灰灰" + cnt.getAndAdd(1);
+        log.info("{}-外部写入缓存: {}", Thread.currentThread(), name);
+        cache.set(name);
+        jdbcTemplate.execute("insert into money (`name`, `money`) values ('" + name + "', " + cnt.get() + ");");
+        registryBeforeCommitOrImmediatelyRun(new Runnable() {
+            @Override
+            public void run() {
+                String last = cache.get();
+                log.info("{}-缓存中的新增数据: {}", Thread.currentThread(), last);
+                try {
+                    Thread.sleep(1000);
+                } catch (InterruptedException e) {
+                    throw new RuntimeException(e);
+                }
+
+                if (hasException) {
+                    // 让这里概率性失败，从而模拟事务回滚的场景
+                    Assert.isTrue(Math.random() > 0.5f, "模拟事务回滚!");
+                }
+            }
+        });
+
+        log.info("transExecute 执行完毕!");
+    }
+
+
+    /**
+     * 注册事务回调-事务提交前执行，如果没在事务中就立即执行
+     *
+     * @param runnable
+     */
+    public static void registryBeforeCommitOrImmediatelyRun(Runnable runnable) {
+        if (runnable == null) {
+            return;
+        }
+        // 处于事务中
+        if (TransactionSynchronizationManager.isSynchronizationActive()) {
+            // 等事务提交前执行，发生错误会回滚事务
+            TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
+                @Override
+                public void beforeCommit(boolean readOnly) {
+                    runnable.run();
+                }
+            });
+        } else {
+            // 马上执行
+            runnable.run();
+        }
+    }
+}

spring-boot/100-transaction-manager/src/main/resources/application.properties

@@ -0,0 +1,10 @@
+## log
+logging.file=logs/info.log
+logging.file.max-history=2
+logging.file.max-size=1GB
+
+## DataSource
+spring.datasource.url=jdbc:mysql://localhost:3306/story?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2b8
+spring.datasource.driver-class-name= com.mysql.cj.jdbc.Driver
+spring.datasource.username=root
+#spring.datasource.password=

spring-boot/pom.xml

@@ -36,6 +36,7 @@
         <module>014-spel-aop</module>
 
         <module>100-mysql</module>
+        <module>100-transaction-manager</module>
         <module>101-jdbctemplate</module>
         <module>101-jdbctemplate-transaction</module>
         <module>102-jpa</module>