Spring的纯注解开发配置
该注解只能写在方法上,表明使用此方法创建一个对象,并且放入spring容器。@Import注解是用来导入配置类或者一些需要前置加载的类。value[]:用于指定properties文件位置。用于指定spring在初始化容器时要扫描的包。用于加载*.properties文件中的配置。basePackages:用于指定要扫描的包。和该注解中的value属性作用一样。name:给当前@Bean注解方法创
1.环境搭建
1.1.创建工程
1.2.待改造的问题(不用注解的开发)
如果不用注解开发,我们发现,之所以我们现在离不开xml配置文件,是因为我们有一处很关键的配置,如果他要也能用注解配置,那么我们就可以脱离xml文件了:
1.2.1.jdbc配置
<context:property-placeholder location="classpath:db.properties">
</context:property-placeholder>
<!--数据源-->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
destroy-method="close">
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="driverClassName" value="${jdbc.driver}" />
<property name="maxActive" value="10" />
<property name="minIdle" value="5" />
</bean>
1.2.2.mybatis配置
<!--sqlSession工厂-->
<bean id="sessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="typeAliasesPackage" value="com.by.pojo"></property>
</bean>
<!--配置MapperScan扫描mapper接口,并把生成的代理类交给spring去管理-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.by.mapper"></property>
<property name="sqlSessionFactoryBeanName" value="sessionFactoryBean"></property>
</bean>
1.2.3.transactional配置
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<!-- 开启spring对注解事务的支持 -->
<tx:annotation-driven transaction-manager="transactionManager"/>
1.2.4.service配置
<!--扫描service-->
<context:component-scan base-package="com.by.service"></context:component-scan>
1.2.5.springmvc配置
<!--配置springmvc要扫描的包-->
<context:component-scan base-package="com.by.controller,com.by.exception"></context:component-scan>
<!--开启注解驱动:配置handlerMapping和handlerAdapter-->
<mvc:annotation-driven conversion-service="cs"></mvc:annotation-driven>
<!--配置日期转换器-->
<bean id="cs" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<set>
<bean class="com.by.converter.MyDateConverter"></bean>
</set>
</property>
</bean>
<!--配置视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<!--配置文件上传解析器-->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="5242880" />
<property name="defaultEncoding" value="UTF-8" />
</bean>
<!--资源映射器:直接放行无须dispatcherServlet去处理-->
<mvc:resources location="/head/" mapping="/head/**"/>
<!--配置拦截器-->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/account/**"/>
<mvc:exclude-mapping path="/account/login"></mvc:exclude-mapping>
<bean class="com.by.interceptor.LoginInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>
1.2.6.servlet配置
<!--配置监听器:监听tomcat启动,加载spring配置文件-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext-*.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<!--前端控制器-->
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!--过滤器-->
<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>
org.springframework.web.filter.CharacterEncodingFilter
</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
2.新注解说明
2.1.@Configuration
-
作用:
用于指定当前类是一个spring配置类,可替换xml配置文件,作用和在spring的xml配置文件中的:
<beans></beans>
是一样的。 -
示例代码:
/**
* spring的配置类
*/
@Configuration//等价于<beans>,当从一个类上加载到该注解时会创建spring容器
public class SpringConfiguration{
}
2.2.@ComponentScan
-
作用:
用于指定spring在初始化容器时要扫描的包。作用和在spring的xml配置文件中的:
<context:component-scan base-package="com.by"/>
是一样的。 -
属性:
basePackages:用于指定要扫描的包。和该注解中的value属性作用一样。
-
示例代码:
/**
* spring的配置类
*/
@Configuration
@ComponentScan(basePackages = "com.by")//等价于<context:component-scan>
public class SpringConfiguration{
}
2.3.@Bean
-
作用:
该注解只能写在方法上,表明使用此方法创建一个对象,并且放入spring容器。作用和在spring的xml配置文件中的:
<bean/>
是一样的。 -
属性:
name:给当前@Bean注解方法创建的对象指定一个名称(即bean的id)。
-
示例代码
public class Dog {
private String nam;
private Integer age;
//set get......
}
@Bean
public Dog dog(){
Dog dog = new Dog();
dog.setNam("二狗");
dog.setAge(18);
return dog;
}
2.4.@PropertySource
-
作用:
用于加载*.properties文件中的配置。作用和在spring的xml配置文件中的:
<context:property-placeholder location="">
是一样的。 -
属性:
value[]:用于指定properties文件位置。如果是在类路径下,需要写上classpath:
-
示例代码
#config.properties
nam=二狗
age=18
@PropertySource("classpath:config.properties")
public class SpringConfiguration {
@Value("${nam}")
private String nam;
@Value("${age}")
private Integer age;
@Bean
public Dog dog(){
Dog dog = new Dog();
dog.setNam(nam);
dog.setAge(age);
return dog;
}
}
2.5.@Import
-
作用:
@Import注解是用来导入配置类或者一些需要前置加载的类。作用和在spring的xml配置文件中的:
<import resource=""></import>
是一样. -
属性:
value[]:用于指定其他配置类的字节码。
-
示例代码
@Configuration
@ComponentScan(basePackages = "com.by")
@Import({Configuration_Other.class})
public class SpringConfiguration {
}
@PropertySource("classpath:config.properties")
public class Configuration_Other {
}
3.Spring的纯注解配置
3.1.DataSourceConfig
import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;
import javax.sql.DataSource;
@PropertySource("classpath:db.properties")
public class JdbcConfig {
@Value("${jdbc.driver}")
private String driver;
@Value("${jdbc.url}")
private String url;
@Value("${jdbc.username}")
private String userName;
@Value("${jdbc.password}")
private String password;
@Bean("dataSource")
public DataSource getDatasource() {
DruidDataSource ds = new DruidDataSource();
ds.setDriverClassName(driver);
ds.setUrl(url);
ds.setUsername(userName);
ds.setPassword(password);
return ds;
}
}
3.2.MybatisConfig
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;
import javax.sql.DataSource;
public class MyBatisConfig {
@Bean
public SqlSessionFactoryBean getSqlSessionFactoryBean(
DataSource dataSource){
SqlSessionFactoryBean ssfb=new SqlSessionFactoryBean();
ssfb.setDataSource(dataSource);
ssfb.setTypeAliasesPackage("com.by.pojo");
return ssfb;
}
@Bean
public MapperScannerConfigurer getMapperScannerConfigurer(){
MapperScannerConfigurer msc=new MapperScannerConfigurer();
msc.setBasePackage("com.by.mapper");
return msc;
}
}
3.3.TxConfig
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import javax.sql.DataSource;
public class TxConfig {
@Bean
public PlatformTransactionManager transactionManager(DataSource dataSource){
DataSourceTransactionManager ds = new DataSourceTransactionManager();
ds.setDataSource(dataSource);
return ds;
}
}
3.4.SpringConfig
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.transaction.annotation.EnableTransactionManagement;
@Configuration
@Import({MyBatisConfig.class, JdbcConfig.class, TxConfig.class})
//等同<context:component-scan base-package="com.by"/>`
@ComponentScan(value = "com.by.service")
//等同于<tx:annotation-driven />,bean的名称默认取transactionManager
@EnableTransactionManagement
public class SpringConfig {
}
3.5.SpringMvcConfig
import com.by.converter.MyDateConverter;
import com.by.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
//等同于<context:component-scan base-package="com.by.controller>
@ComponentScan("com.by.controller")
//等同于<mvc:annotation-driven></mvc:annotation-driven>
@EnableWebMvc
public class SpringMvcConfig implements WebMvcConfigurer {
@Bean
public ViewResolver viewResolver() {
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/pages/"); // 设置视图文件所在目录
viewResolver.setSuffix(".jsp"); // 设置视图文件后缀名
return viewResolver;
}
@Bean
public CommonsMultipartResolver multipartResolver(){
CommonsMultipartResolver commonsMultipartResolver=new CommonsMultipartResolver();
return commonsMultipartResolver;
}
@Override
public void addFormatters(FormatterRegistry registry) {
registry.addConverter(new MyDateConverter());
}
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/emp/**");
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/head/**").addResourceLocations("/head/");
}
}
3.6.WebConfig
import org.springframework.web.filter.CharacterEncodingFilter;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
import javax.servlet.Filter;
/**
* 当类扩展了AbstractAnnotationConfigDispatcherServletlnitializer并将其部署到 Servlet容器时,
* 容器会自动发现它,并用它来配置Servlet环境
*/
public class WebConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
//加载Spring配置类
protected Class<?>[] getRootConfigClasses() {
return new Class[]{SpringConfig.class};
}
//加载SpringMVC配置类
protected Class<?>[] getServletConfigClasses() {
return new Class[]{SpringMvcConfig.class};
}
//设置SpringMVC请求地址拦截规则
protected String[] getServletMappings() {
return new String[]{"/"};
}
//设置post请求中文乱码过滤器
@Override
protected Filter[] getServletFilters() {
CharacterEncodingFilter filter = new CharacterEncodingFilter();
filter.setEncoding("utf-8");
return new Filter[]{filter};
}
}
3.7.删除xml配置文件
3.8.修改web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>
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