代码方式配置和xml文件方式混合配置spring

第一步

@Order(1)public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{    private static final PropertiesLoader propertiesLoader = new PropertiesLoader();    @Override    protected Class<?>[] getRootConfigClasses() {        return new Class<?>[0];    }    @Override    protected Class<?>[] getServletConfigClasses() {        return new Class<?>[]{MvcConfig.class};    }    @Override    protected String[] getServletMappings() {        return new String[]{"/"};    }    @Override    protected Filter[] getServletFilters() {        return super.getServletFilters();    }    @Override    protected WebApplicationContext createServletApplicationContext() {        AnnotationConfigWebApplicationContext servletAppContext = new AnnotationConfigWebApplicationContext();        Class<?>[] configClasses = getServletConfigClasses();        if (!ObjectUtils.isEmpty(configClasses)) {            servletAppContext.register(configClasses);        }        //读取spring.properties配置文件，这里主要是设置spring的profile        Properties prop = propertiesLoader.load("spring.properties");        servletAppContext.getEnvironment().setActiveProfiles(prop.getProperty("spring.profiles.active"));        return servletAppContext;    }}

其实上一步相当于定义了
* Dispatcher-拦截路径为“/”
* 定义了ApplicationContext
其中 PropertiesLoader 主要在初始化上下文的时候，加载一些配置文件信息

package com.lizo.config.utils;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStream;import java.util.Properties;/** * Created by hzlizhou on 2016/9/13. */public class PropertiesLoader {    public Properties load(String fileName) {        Properties prop = new Properties();        InputStream im = null;        try {            im = findFile(fileName);            prop.load(im);        } catch (IOException ignore) {        } finally {            if (im != null) {                try {                    im.close();                } catch (IOException ignore) {                }            }        }        return prop;    }    private InputStream findFile(String fileName) throws FileNotFoundException {        InputStream im = findInWorkingDirectory(fileName);        if (im == null) im = findInClasspath(fileName);        if (im == null) im = findInSourceDirectory(fileName);        if (im == null) throw new FileNotFoundException(String.format("File %s not found", fileName));        return im;    }    private InputStream findInSourceDirectory(String fileName) throws FileNotFoundException {        return new FileInputStream("src/main/resources/" + fileName);    }    private InputStream findInClasspath(String fileName) {        return Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName);    }    private InputStream findInWorkingDirectory(String fileName) {        try {            return new FileInputStream(System.getProperty("user.dir") + fileName);        } catch (FileNotFoundException e) {            return null;        }    }}

第二步 Spring MVC 配置

import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.PropertySource;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;/** * Created by hzlizhou on 2016/9/13. */@Configuration@EnableWebMvc@ComponentScan("com.lizo")public class MvcConfig extends WebMvcConfigurerAdapter {    /*    @Override    public void addResourceHandlers(ResourceHandlerRegistry registry) {        registry.addResourceHandler("/static/**").addResourceLocations("/static/");    }    */}

其中 EnableWebMvc 相当于xml配置中

<mvc:annotation-driven/>

也就是自动注册了RequestMappingHandlerMapping, RequestMappingHandlerAdapter 和 ExceptionHandlerExceptionResolver

第三步 配置dataSource

首先使用一个config类，用来加载其他配置文件

@Configuration@PropertySource({"classpath:spring.properties"})@Import(DataSourceConfig.class)@ImportResource("classpath:spring-db.xml")public class AppConfig {}

• @PropertySource——用于加载配置文件
• @Import——加载使用@Configuration注解的配置类
• @ImportResource——加载xml形式的配置文件

@Configuration@PropertySource("classpath:${spring.profiles.active}/jdbc.properties")public class DataSourceConfig {    @Value("${jdbcDriver}")    String jdbcDriver;    @Value("${jdbcUrl}")    String jdbcUrl;    @Value("${jdbcUser}")    String jdbcUser;    @Value("${jdbcPassword}")    String jdbcPassword;    @Bean(name= "dataSource")    public DataSource dataSource(){        DruidDataSource druidDataSource = new DruidDataSource();        druidDataSource.setDriverClassName(jdbcDriver);        druidDataSource.setUrl(jdbcUrl);        druidDataSource.setUsername(jdbcUser);        druidDataSource.setPassword(jdbcPassword);        return druidDataSource;    }}

需要注意的是，上面加载配置文件的路径使用了变量（profile),这样就可以根据不同环境加载不同的配置文件信息

第四步 使用xml配置mybatis

虽然使用代码的配置方式也能配置，这里只是为了说明（其实就和xml配置文件是一样）

<?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:tx="http://www.springframework.org/schema/tx"       xmlns:context="http://www.springframework.org/schema/context"       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">    <!-- 数据源事物管理 -->    <bean id="transactionManager"          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">        <property name="dataSource" ref="dataSource"/>    </bean>    <!-- jdbc 模板 -->    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">        <property name="dataSource" ref="dataSource"/>    </bean>    <!-- mybatis 配置 -->    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">        <property name="dataSource" ref="dataSource" />        <property name="mapperLocations">            <array>                <value>classpath*:/**/*mapper.xml</value>            </array>        </property>    </bean>    <!-- 扫描mybatis映射接口类 -->    <bean id="MapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">        <property name="basePackage" value="com.lizo.mapper"/>        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />    </bean>    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">        <constructor-arg index="0" ref="sqlSessionFactory" />    </bean></beans>

第五步 单元测试

@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes  = AppConfig.class)public class TestMapperTest {    @Autowired    TestMapper testMapper;    @Test    public void test(){        Assert.assertNotNull(testMapper.test());     }}

总结

既然能够兼容两种模式，那么就可以有选择性的选择使用