手把手教自己使用Java形式配置SSM框架

话不多说直接上代码,

不懂springIoC容器注入的阅读一下https://blog.youkuaiyun.com/Black1499/article/details/85272039;

有关xml方式配置ssm框架的可以看一下https://blog.youkuaiyun.com/Black1499/article/details/83961684，可以和下面的java配置的形式对比一下。

一、配置MyBatis

这里关于properties配置文件的读取，我采用了混合搭配的形式,就不再一个一个详细说明了。

• 一种是注入Enviroment类，通过它的方法来读取对应的值

• 一种是SpringEL表达式读取注入

    @Component
    @EnableTransactionManagement //该注解配置spring事务管理
    public class MybatisConfig {
    
        @Value("${jdbc.driver}")
        private String driver;
    
        @Autowired
        private Environment environment;
    
        @Bean("dataSource")
        public DataSource dataSourceConfig() throws PropertyVetoException {
            // 使用c3p0连接池
            ComboPooledDataSource source = new ComboPooledDataSource();
            source.setDriverClass(driver);
            source.setJdbcUrl("jdbc:mariadb://localhost:3306/testdb");
            source.setUser(environment.getProperty("jdbc.user"));
            source.setPassword("123456");
            return source;
        }
    
        @Bean("sqlSessionFactoryBean")
        public SqlSessionFactoryBean sqlSessionFactoryBeanConfig() throws PropertyVetoException, IOException {
            SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
            factoryBean.setDataSource(this.dataSourceConfig());
            factoryBean.setTypeAliasesPackage("com.lzx.entity");
            factoryBean.setConfigLocation(new ClassPathResource("mybatis-config.xml"));
            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            factoryBean.setMapperLocations(resolver.getResources("mappers/*.xml"));
            return factoryBean;
        }
    
        @Bean("transactionManager")
        public DataSourceTransactionManager dataSourceTransactionManagerConfig() throws PropertyVetoException {
            return new DataSourceTransactionManager(this.dataSourceConfig());
        }
    
    
        // JdbcTemplate
        @Bean
        public JdbcTemplate  jdbcTemplateConfig() throws PropertyVetoException {
            return new JdbcTemplate(dataSourceConfig());
        }
    }
  

二、配置数据访问层

@Configuration // 该注解表示这个类是一个配置类
@ComponentScan(basePackages = "com.lzx.dao") // 扫描数据访问层
@PropertySource("classpath:jdbc.properties") // 读取properties配置文件
@Import(MybatisConfig.class) // 导入MyBatis的配置
public class SpringDaoConfig  {

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean("mapperScannerConfigurer")
    public MapperScannerConfigurer mapperScannerConfigurerConfig() {
        MapperScannerConfigurer configurer = new MapperScannerConfigurer();
        configurer.setSqlSessionFactoryBeanName("sqlSessionFactoryBean");
        configurer.setBasePackage("com.lzx.dao");
        return configurer;
    }
}

三、配置业务逻辑层

@ComponentScan(basePackages = "com.lzx.service") // 扫描业务逻辑层
@Configuration
public class SpringServiceConfig {
}

四、配置表示层

@ComponentScan(basePackages = "com.lzx.web")
@Configuration
@EnableWebMvc // 表明该类是配置controller的
public class SpringWebConfig implements WebMvcConfigurer {

    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        registry.jsp("/WEB-INF/jsp/", ".jsp");
    }

//    @Bean
//    public InternalResourceViewResolver internalResourceViewResolverConfig() {
//        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
//        resolver.setViewClass(JstlView.class);
//        resolver.setPrefix("/WEB-INF/jsp/");
//        resolver.setSuffix(".jsp");
//        return resolver;
//    }

    @Bean
    public StandardServletMultipartResolver multipartResolverConfig() {
        return new StandardServletMultipartResolver();
    }
}

五、去除web.xml，采用java配置

public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[] { RootConfig.class };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[] { SpringWebConfig.class };
    }

    @Override
    protected String[] getServletMappings() {
		// 配置页面映射路径
        return new String[] { "/" };
    }

    @Override
    protected Filter[] getServletFilters() {
		// 配置机制编码防止乱码
        CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter("UTF-8");
        return new Filter[]{characterEncodingFilter};
    }
}

六、配置Spring入口

注意上面的所有配置文件建议大家放到一个包内。

@Configuration
@ComponentScan(basePackages = {"com.lzx.config"},
        excludeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION, value = EnableWebMvc.class)}
)
@EnableAspectJAutoProxy // 配置spring aop
public class RootConfig {
}

简单说明一下 @ComponentScan 注解的作用。由于我把所有的配置文件放到了一个名为config的包内，所以我们要统一扫描一下，但是要把Spring MVC给排除掉。因为spring为父容器，mvc是子容器。如果把mvc也注入到spring中，controller类会报错。二者是依赖管理，mvc里面的bean可以被spring使用，但是mvc不能使用spring里面的bean。所以要把mvc给排除掉。

代码分享

直接拿去使用，注意更改相关包的路径
https://github.com/Black1499/ssm_spring_study/tree/master/src/main/java/com/lzx/config