springboot管理事务_springboot 事务maven

Managing Transactions

1.目标

建立一个简单的JDBC应用，设置数据库的事务而不用写JDBC代码。

2.代码

pom文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.4.3</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.example</groupId>
  <artifactId>managing-transactions</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>managing-transactions</name>
  <description>Demo project for Spring Boot</description>
  <properties>
    <java.version>1.8</java.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.13</version>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-jdbc</artifactId>
    </dependency>
 
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>
 
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
 
</project>

 写一个基于JDBC服务，将学生姓名登记到系统中。

新建src/main/java/com/example/managingtransactions/BookingService.java

package com.example.managingtransactions;
 
import java.util.List;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
 
@Component
public class BookingService {
 
  private final static Logger logger = LoggerFactory.getLogger(BookingService.class);
 
  private final JdbcTemplate jdbcTemplate;
 
  public BookingService(JdbcTemplate jdbcTemplate) {
    this.jdbcTemplate = jdbcTemplate;
  }
 
  @Transactional
  public void book(String... persons) {
    for (String person : persons) {
      logger.info("Booking " + person + " in a seat...");
      jdbcTemplate.update("insert into BOOKINGS(FIRST_NAME) values (?)", person);
    }
  }
 
  public List<String> findAllBookings() {
    return jdbcTemplate.query("select FIRST_NAME from BOOKINGS",
      (rs, rowNum) -> rs.getString("FIRST_NAME"));
  }
 
}

 这里有一个book方法，使用JdbcTemple通过循环将每个学生插入到BOOKINGS表中。该方法使用@Transactional标记，意思是整个执行过程中，有任何失败都会回滚到之前的状态。也就是说，如果任何一个学生添加失败，就不会有学生添加到BOOKINGS表中。

新建src/main/java/com/example/managingtransactions/ManagingTransactionsApplication.java

package com.example.managingtransactions;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class ManagingTransactionsApplication {
 
  public static void main(String[] args) {
    SpringApplication.run(ManagingTransactionsApplication.class, args);
  }
 
}

@SpringBootApplication，是简单的使用方法它包括：

@Configuration，将一个类作为bean定义的源代码添加到应用上下文中。

@EnableAutoConfiguration，告诉SpringBoot启动的时候将classpath路径下的、其他的bean和各种配置添加进来。例如，如果spring-webmvc在classpath中，那么该标记将应用作为一个web应用激活关键的行为，比如说建立DispatcherServlet。

@ComponentScan，告诉Spring在com/exampe下查找其他components、configurations和services，让他们能够找到controllers。

main方法使用SpringApplication.run()启动一个应用，你可能发现没有任何XML文件，没有web.xml文件。该web应用是100%纯的java代码。

该应用没有任何的配置。Spring Boot监测到spring-jdbc和h2在classpath中，然后会自动创建一个DataSource和一个JdbcTemplate。以上这些由DataSourceTransactionManager进行管理。

3.运行测试

使用CommandLineRunner一样可以达到这样的效果。

 新建src/main/java/com/example/managingtransactions/AppRunner.java

package com.example.managingtransactions;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;
 
@Component
class AppRunner implements CommandLineRunner {
 
  private final static Logger logger = LoggerFactory.getLogger(AppRunner.class);
 
  private final BookingService bookingService;
 
  public AppRunner(BookingService bookingService) {
    this.bookingService = bookingService;
  }
 
  @Override
  public void run(String... args) throws Exception {
    bookingService.book("Alice", "Bob", "Carol");
    Assert.isTrue(bookingService.findAllBookings().size() == 3,
        "First booking should work with no problem");
    logger.info("Alice, Bob and Carol have been booked");
    try {
      bookingService.book("Chris", "Samuel");
    } catch (RuntimeException e) {
      logger.info("v--- The following exception is expect because 'Samuel' is too " +
          "big for the DB ---v");
      logger.error(e.getMessage());
    }
 
    for (String person : bookingService.findAllBookings()) {
      logger.info("So far, " + person + " is booked.");
    }
    logger.info("You shouldn't see Chris or Samuel. Samuel violated DB constraints, " +
        "and Chris was rolled back in the same TX");
    Assert.isTrue(bookingService.findAllBookings().size() == 3,
        "'Samuel' should have triggered a rollback");
 
    try {
      bookingService.book("Buddy", null);
    } catch (RuntimeException e) {
      logger.info("v--- The following exception is expect because null is not " +
          "valid for the DB ---v");
      logger.error(e.getMessage());
    }
 
    for (String person : bookingService.findAllBookings()) {
      logger.info("So far, " + person + " is booked.");
    }
    logger.info("You shouldn't see Buddy or null. null violated DB constraints, and " +
        "Buddy was rolled back in the same TX");
    Assert.isTrue(bookingService.findAllBookings().size() == 3,
        "'null' should have triggered a rollback");
  }
 
}

通过命令行执行

mvn spring-boot:run