spring - 创建名为 'sqlSessionFactory' 的 bean 时出错...调用 init 方法失败；嵌套异常是 java.lang.NullPointerException

Question

我正在尝试将 spring-mybatis 集成到我的应用程序中。我使用的是 spring 4.1.4 和 mybatis 3.2.8 java 7，服务器是 WebSphere Application Server Liberty。我正在使用 spring java 配置类。仅当我部署 war 文件时才会显示此错误，如果我使用 Eclipse 部署项目，则一切正常。在 Tomcat 8 中部署也可以正常工作。

@Configuration
@MapperScan("x.y.z.mappers")
@PropertySource("classpath:/x/y/z/data_source.properties")
@EnableTransactionManagement
public class DataAccessConfiguration {
    @Autowired
    private Environment env;
    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("driver"));
        dataSource.setUrl(env.getProperty("url"));
        dataSource.setUsername(env.getProperty("user"));
        dataSource.setPassword(env.getProperty("password"));
        return dataSource;
    }
    @Bean
    public DataSourceTransactionManager transactionManager() {
        return new DataSourceTransactionManager(dataSource());
    }
    @Bean
    public SqlSessionFactoryBean sqlSessionFactory() throws Exception {     
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        sessionFactory.setTypeAliasesPackage("x.y.z.portal.model");
       return sessionFactory;
       }
    }

我得到了这个堆栈跟踪

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in a.b.c.DataAccessConfiguration: Invocation of init method failed; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1566)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1127)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1051)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1280)
... 60 more

Caused by: java.lang.NullPointerException
at java.io.FilterInputStream.read(FilterInputStream.java:133)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:325)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:177)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:154)
at java.io.BufferedReader.readLine(BufferedReader.java:317)
at java.io.BufferedReader.readLine(BufferedReader.java:382)
at org.apache.ibatis.io.DefaultVFS.list(DefaultVFS.java:93)
at org.apache.ibatis.io.VFS.list(VFS.java:193)
at org.apache.ibatis.io.ResolverUtil.find(ResolverUtil.java:216)
at org.apache.ibatis.type.TypeAliasRegistry.registerAliases(TypeAliasRegistry.java:127)
at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:399)
at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:355)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1625)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1562)

Answer 1

尝试将您的应用程序与 mybatis 集成。将以下代码添加到 spring-dispatcher-servlet.xml。

 <context:property-placeholder location="x/y/z/data_source.properties"/>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
            <property name="driverClassName"><value>${database.driver}</value></property>
            <property name="url"><value>${database.url}</value></property>
            <property name="username"><value>${database.username}</value></property>
            <property name="password"><value>${database.password}</value></property>
            <property name="maxActive"><value>${database.maxactiveconnections}</value></property>
            <property name="maxIdle"><value>${database.idleconnections}</value></property>
            <property name="initialSize"><value>${database.initialSize}</value></property>

    </bean>   

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="/WEB-INF/mybatis-config.xml"/>
     </bean>

     <bean id="Dao" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>    
        <property name="mapperInterface" value="com.dao.Dao" />
    </bean>