SPRING学习（三十七）--SPRING集成MYBATIS（二）

通过spring集成mybatis，可以更快速方便的搭建与数据库链接的框架。与上一章节相比，减少了mybatisCfg.xml文件，减少了mybatisUtil.java工具类，更简单的添加事务管理，这些都在spring的配置文件中实现。

1、pom.xml文件增加依赖包：

　　 <!--propertiesUtil 读取配置文件-->
    <dependency>
        <groupId>commons-configuration</groupId>
        <artifactId>commons-configuration</artifactId>
        <version>1.10</version>
    </dependency>

    <properties>
        <spring.version>4.0.5.RELEASE</spring.version>
    </properties>
    <!-- mysql驱动 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.13</version>
    </dependency>
    <!-- mybatis驱动包 -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.1</version>
    </dependency>
    <!--mybatis-spring适配器 -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.0</version>
    </dependency>
    <!--Spring java数据库访问包，在本例中主要用于提供数据源 -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <!-- 为JDBC、Hibernate、JDO、JPA等提供的一致的声明式和编程式事务管理。 -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>${spring.version}</version>
    </dependency>

2、配置数据源db.properties

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mytestdatabase?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
username=qiaozhong
password=1

3、编写spring配置文件spring-mybatis.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns= "http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd ">
    
    <!-- 引入配置文件 -->
    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:mybatisConfig/db.properties" />
    </bean>

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${driver}" />
        <property name="url" value="${url}" />
        <property name="username" value="${username}" />
        <property name="password" value="${password}" />
    </bean>

    <!-- spring和MyBatis完美整合，不需要mybatis的配置映射文件 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!-- 自动扫描mapping.xml文件，**表示迭代查找 -->
        <property name="mapperLocations" value="classpath:mybatis/**.xml" />
    </bean>

    <!-- DAO接口所在包名，Spring会自动查找其下的类 ,包下的类需要使用@MapperScan注解,否则容器注入会失败 -->
    <bean id="mapperScanConfig" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="mybatis.dao" />
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    </bean>
    
    <!-- (事务管理)transaction manager, use JtaTransactionManager for global tx -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>
</beans>

4、编写DO文件User.java

package mybatis.DO;

public class User {
    private Long id;

    private String name;

    private String age;

    private String sex;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age == null ? null : age.trim();
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex == null ? null : sex.trim();
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", age=" + age + ", sex="
                + sex + "]";
    }
    
}

5、编写dao文件UserMapper.java，要用注解@MapperScan进行注解

package mybatis.dao;

import java.util.List;
import org.mybatis.spring.annotation.MapperScan;
import mybatis.DO.User;

@MapperScan
public interface UserMapper {
    int deleteByPrimaryKey(Long id);

    int insert(User record);

    User selectByPrimaryKey(Long id);

    List<User> selectAll();

    int updateByPrimaryKey(User record);
}

6、编写测试类SpringMybatisTest.java

package mybatis.test;

import java.util.List;
import mybatis.DO.User;
import mybatis.dao.UserMapper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringJUnit4ClassRunner.class) 
@ContextConfiguration("/springConfig/spring-mybatis.xml") 
public class SpringMybatisTest {
    
    @Autowired(required=false)
    @Qualifier("userMapper")
    private UserMapper userMapperDao;
    
    @Test
    @Transactional//开启事务管理
    public void testConfigurationAnnotion(){
            try {
                List<User> users = userMapperDao.selectAll();
                for (int i = 0; i < users.size(); i++) {
                    System.out.println(users.get(i));
                }
                
                User user = new User();
                user.setId(2L);
                user.setName("name1");
                user.setAge("25");
                user.setSex("male");
                userMapperDao.insert(user);
                
                String nullString= null;
                System.out.println(nullString.equals("1"));
                
                User user2 = new User();
                user2.setId(3L);
                user2.setName("name2");
                user2.setAge("28");
                user2.setSex("female");
                userMapperDao.insert(user2);
            } catch (Exception e) {
                e.printStackTrace();
            }
    }
}

数据库表中原有一条数据：

测试结果：

User [id=1, name=qiaozhong, age=30, sex=male]
java.lang.NullPointerException
    at mybatis.test.SpringMybatisTest.testConfigurationAnnotion(SpringMybatisTest.java:39)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:233)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:176)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
2019-11-18 21:29:53.956 [main] org.springframework.test.context.transaction.TransactionalTestExecutionListener INFO  - Rolled back transaction after test execution for test context [DefaultTestContext@b684286 testClass = SpringMybatisTest, testInstance = mybatis.test.SpringMybatisTest@880ec60, testMethod = testConfigurationAnnotion@SpringMybatisTest, testException = [null], mergedContextConfiguration = [MergedContextConfiguration@3f3afe78 testClass = SpringMybatisTest, locations = '{classpath:/springConfig/spring-mybatis.xml}', classes = '{}', contextInitializerClasses = '[]', activeProfiles = '{}', contextLoader = 'org.springframework.test.context.support.DelegatingSmartContextLoader', parent = [null]]]
  2019-11-18 21:29:53.959 [Thread-0] org.springframework.context.support.GenericApplicationContext INFO  - Closing org.springframework.context.support.GenericApplicationContext@5f2050f6: startup date [Mon Nov 18 21:29:52 CST 2019]; root of context hierarchy
  

结果分析：

1、打印了User [id=1, name=qiaozhong, age=30, sex=male]，说明已经链接到数据库查到数据。

2、执行后，数据库表中数据还是只有一条，说明测试方法中的两个insert语句都没有插入成功。因为在第一个插入语句成功插入表后，有代码抛异常，开启了事务管理之后，会将第一个插入语句回滚。