spring整合mybatis,springMVC的0配置文件方式

　　0配置文件的形式主要是采用spring3.0提供的@configuration注解和spring容器在启动的时候会加载实现了WebApplicationInitializer的类,并调用其onStartUp的方法的特性去实现.

　　具体做法如下:

　　1.建立MyWebAppInitializer去实现WebApplicationInitializer接口,并且去重写其onStartUp方法.实际上这个类取代了web.xml的配置.代码如下:

public class MyWebAppInitializer implements WebApplicationInitializer{

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        //相当于在web.xml在配置spring启动用的ContextLoaderListener
        AnnotationConfigWebApplicationContext rootContext=new AnnotationConfigWebApplicationContext();
        rootContext.register(AppConfig.class);
        servletContext.addListener(new ContextLoaderListener(rootContext));
        //相当于在web.xml在配置DispatcherServlet
        AnnotationConfigWebApplicationContext webContext=new AnnotationConfigWebApplicationContext();
        webContext.register(WebConfig.class);
        Dynamic registration = servletContext.addServlet("dispatcher",new DispatcherServlet(webContext));
        registration.setLoadOnStartup(1);
        registration.addMapping("/");
    }

}

　　2.建立WebConfig.class.这个类用于取代spring的配置文件springmvc.xml.代码如下:相关注解的解释写在注释中.

@EnableWebMvc        //开启springmvc的配置
@Configuration        //开启基于Java类的配置
@ComponentScan(basePackages="com.xyy.web")
public class WebConfig extends WebMvcConfigurerAdapter{
    //配置与dispatcherServlet相关联的bean
    @Bean//代表这是一个bean.spring容器会将其放在容器中.
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver=new InternalResourceViewResolver();
        resolver.setPrefix("/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);//使得可以在jsp页面中可以通过${}访问bean
        return resolver;
    }
    //开启静态文件的访问.
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

}

　　3.建立AppConfig.class.它用于取代applicationContext.xml.这里我们使用了c3p0数据库连接池配合mybatis框架使用

@EnableAspectJAutoProxy//开启自动注解扫描
@EnableTransactionManagement//配置事务管理
@Configuration
@ComponentScan(basePackages="com.xyy")//扫描注解
public class AppConfig {
    //配置c3p0数据源
    @Bean
    public DataSource dataSource() {
        ComboPooledDataSource dataSource=new ComboPooledDataSource();
        try {
            dataSource.setDriverClass("com.mysql.jdbc.Driver");
        } catch (PropertyVetoException e) {
            e.printStackTrace();
        }
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUser("root");
        dataSource.setPassword("root");
        return dataSource;
    }
    //配置SqlSessionFactoryBean
    @Bean
    public SqlSessionFactoryBean sqlSessionFactory() {
        SqlSessionFactoryBean bean=new SqlSessionFactoryBean();
        bean.setConfigLocation(new ClassPathResource("SqlMapConfig.xml"));
        bean.setDataSource(dataSource());
        return bean;
    }
    //配置开启Mapper扫描
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer configurer=new MapperScannerConfigurer();
        configurer.setBasePackage("com.xyy.mapper");
        return configurer;
    }
    //配置开启DataSourceTransactionManager
    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager() {
        DataSourceTransactionManager manager=new DataSourceTransactionManager();
        manager.setDataSource(dataSource());
        return manager;
    }
}

　　4.至此,我们就可以正常的建立Controller类书写代码了.不过,不要忘记在对应的类上加上@controller,@service,@repository哦.

　 5.此外,为了防止会出现乱码的情况,我们最好再配上spring提供的CharacterEncodingFilter去解决乱码问题.方式如下,也是在MyWebAppInitializer类中配置的: