org.springframework.beans.factory.UnsatisfiedDependencyException异常问题的解决

最近学了IDEA和SpringBoot+MyBatis了，正所谓学以致用，于是用所学的来做项目，单元测试时报了下面的异常：

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'adminController': Unsatisfied dependency expressed through field 'adminService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'adminService': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'adminMapper' defined in file [E:\IDEA Project\shfw\target\classes\com\kvc\shfw\admin\mapper\AdminMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate

检查了一遍又一遍，特别是application.properties关于mapper.xml的配置，启动类是否添加Mapper的注解，serviceImpl是否引入了mapper的接口，发现都没问题，于是上网搜索，试了很多种办法，方法大抵也是说要去检查上面的那几项，可是我都检查了N回了，又按照网友给的方案，在pom.xml的<build></build>中加入下面的代码：

 <!-- 添加资源 -->
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <!-- src/main/resources下的指定资源放行 -->
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.yml</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>

结果依然无效，一筹莫展之际，只有把目光转向控制台，从控制台打印的信息入手，此时，下面的代码引起我的注意：

An attempt was made to call a method that does not exist. The attempt was made from the following location:

    org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:426)

The following method did not exist:

    org.apache.ibatis.session.Configuration.setVfsImpl(Ljava/lang/Class;)V

The method's class, org.apache.ibatis.session.Configuration, is available from the following locations:

    jar:file:/C:/Users/shensh.CREATIVE/.m2/repository/org/mybatis/mybatis/3.2.8/mybatis-3.2.8.jar!/org/apache/ibatis/session/Configuration.class

It was loaded from the following location:

    file:/C:/Users/shensh.CREATIVE/.m2/repository/org/mybatis/mybatis/3.2.8/mybatis-3.2.8.jar


Action:

Correct the classpath of your application so that it contains a single, compatible version of org.apache.ibatis.session.Configuration

就是最后一行代码：Correct the classpath of your application so that it contains a single, compatible version of org.apache.ibatis.session.Configuration，把该行代码复制去搜索，有人说是jar冲突，而我的异常有提到mybatis-3.2.8.jar，会不会是mybatis jar冲突了呢，于是打开pom.xml,搜索mybatis，果不其然，有两个地方引入了关于mybatis中，一处是如下：

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>${mybatis.spring.boot.starter.version}</version>
</dependency>

另一处是：

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.2.8</version>
</dependency>

我把后面这个引入去掉，重新启动，终于正常了。

这个问题给我体会是：

1.同样的异常，产生的原因有千奇百样种，不对着根源（控制台打印信息）去找解决方案，人云亦云，用别人的办法解决你的异常，由于异常产生的根源不同，那么这时问题解决不了的。我经常这样，异常产生了，一大堆英文，懒得去看，去翻译，直接复制到网上找解决办法，这点很不好，以后要痛改前非，遇到异常不慌张，不着急，静下心来好好理解下控制台的意思，再有针对性地寻求解决方案，远比遇到异常就像个无头苍蝇似的，到处乱撞，生搬硬套别人的解决办法，要强得多，要更快找到适合的解决办法。

2.mybatis-spring-boot-starter jar已经集成了mybatis的jar包了，不必要单独引入mybatis的jar了。