1、概念
所谓的SSM
整合即前面学的
Spring、
SpringMVC、
MyBatis对其进行的整合 整合前存在的问题:所有的
bean都存储在同一个
IoC容器中,无法避免
service注入
controller`等问题
解决方案:
2、采用父子容器
2.1、父子容器关系
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1、特点:
父容器和子容器是相互隔离的,它们内部可以存在名称相同的
bean
子容器可以访问父容器中的
bean
,而父容器不能访问子容器中的bean
调用子容器的
getBean
方法时,会沿着当前容器开始向父容器进行查找,直到找到对应的bean
为止子容器中可以通过注入父容器中的
bean
,而父容器中无法注入子容器中的bean
2、优点
采用父子容器可以避免依赖层次混乱(
service
注入controller
)将相互不关心的东西隔开,可以有效避免一些不必要的错误,而父子容器加载的速度也会快一些
2.2、父子容器配置
1、子容器的配置文件:dispatcherServlet.xml
<context:component-scan base-package="com.sj.controller" />
controller
、SpringMVC
专用的一些bean
2、父容器配置文件:applicationContext.xml
service
、dao
、其他(非SpringMVC
专用的bean
、共用的bean
等)
<context:component-scan base-package="com.sj.service" />
2.3、父子容器加载创建
1、子容器加载创建
<servlet>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<!-- 子容器 -->
<param-value>classpath:dispatcherServlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
2、父容器加载创建
<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>
2.3、MyBatis补充
如果将Mapper
文件跟dao
放在相同目录下,且文件名跟dao
一样
那么通过MapperScannerConfigurer
就可以找到Mapper
文件
不需要在配置SqlSessionFactoryBean
的mapperLocation
属性
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可以设置
SqlSessionFactoryBean
的configLocation
属性,指定MyBatis
核心配置文件的位置
<property name="configLocation" value="classpath:mybatis-config.xml" />
2.4、Maven
配置
默认情况下,Maven
并不会将源代码文件夹中的配置文件(propertis
、xml
等)打包
如想打包的话,需要额外配置
<build>
<!-- 说明资源文件位置-->
<resources>
<resource>
<directory>src/main/resources</directory>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
</resource>
</resources>
</build>
3、纯注解
1、继承自 AbstractAnnotationConfigDispatcherServletInitializer
类取代web.xml
文件
public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
// 父容器的配置类
@Override
protected Class<?>[] getRootConfigClasses() {
return new Class[]{SpringConfig.class};
}
// 子容器的配置类(SpringMVC相关的配置类)
@Override
protected Class<?>[] getServletConfigClasses() {
return new Class[]{SpringMVCConfig.class};
}
// 配置DispatcherServlet的url-pattern
@Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
}
2、纯注解实现<mvc:default-servlet-handler/>
,实现在webapp
下可以访问静态资源
3、拦截器的原来实现
<mvc:interceptors>
<mvc:interceptor>
<!-- 需要拦截的路径可以写多个-->
<!-- **代表当前目录下的所有内容(包括子目录)-->
<mvc:mapping path="/**"/>
<!-- 排除asset目录的所有内容-->
<mvc:exclude-mapping path="/asset/**"/>
<!-- 排除所有html-->
<mvc:exclude-mapping path="/**/*.html"/>
<bean class="com.sj.interceptor.MyInterceptor" />
</mvc:interceptor>
</mvc:interceptors>
4、InternalResourceViewResolver
原来实现
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" >
<property name="order" value="1" />
<property name="prefix" value="/WEB-INF/page2/"/>
<property name="suffix" value=".jsp"/>
<property name="viewClass" value="com.sj.view.MyView" />
</bean>
5、MappingJackson2HttpMessageConverter
原来实现
<mvc:annotation-driven conversion-service="conversionService">
<mvc:message-converters>
<!-- 影响string返回值内容-->
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="defaultCharset" value="UTF-8"/>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
对应的注解实现方式如下:
@ComponentScan({"com.sj.controller", "com.sj.interceptor"})
@EnableWebMvc // 纯注解开发MVC,必须添加
public class SpringMVCConfig implements WebMvcConfigurer {
@Autowired
private MyInterceptor myInterceptor;
@Autowired
private DateConverter dateConverter;
// 相当于<mvc:default-servlet-handler/>
// 用以处理静态资源
@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
configurer.enable();
}
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(myInterceptor)
.addPathPatterns("/**")
.excludePathPatterns("/asset/**", "/**/*.html");
}
@Bean
public InternalResourceViewResolver viewResolver() {
InternalResourceViewResolver resolver = new InternalResourceViewResolver();
resolver.setPrefix("/WEB-INF/page/");
resolver.setSuffix(".jsp");
return resolver;
}
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
StringHttpMessageConverter converter = new StringHttpMessageConverter();
converter.setDefaultCharset(StandardCharsets.UTF_8);
converters.add(converter);
}
@Override
public void addFormatters(FormatterRegistry registry) {
registry.addConverter(dateConverter);
}
}
6、异常处理SimpleMappingExceptionResolver原来实现
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.RuntimeException">/WEB-INF/page/rumtime.jsp</prop>
<prop key="java.io.IOException">/WEB-INF/page/io.jsp</prop>
<prop key="java.lang.ClassNotFoundException">/WEB-INF/page/not.jsp</prop>
</props>
</property>
<!-- 异常对象的属性名(可以通过EL表达式访问)-->
<property name="exceptionAttribute" value="ex" />
<!-- 其他错误页面异常-->
<property name="defaultErrorView" value="/WEB-INF/page/error.jsp" />
</bean>
注解实现类前面加上@ControllerAdvice
@ControllerAdvice
public class MyExceptionResolver2 {
@ExceptionHandler({ArithmeticException.class, IOException.class})
public ModelAndView resolveException1(Exception ex) {
ModelAndView mv = new ModelAndView();
mv.addObject("ex", ex);
mv.setViewName("/WEB-INF/page/rumtime.jsp");
return mv;
}
@ExceptionHandler()
public ModelAndView resolveException2(Exception ex) {
ModelAndView mv = new ModelAndView();
mv.addObject("ex", ex);
mv.setViewName("/WEB-INF/page/error.jsp");
return mv;
}
}
7、设置拦截器,实现WebApplicationInitializer
接口
之前用法在web.xml
实现
<!--解决post请求乱码问题-->
<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>
使用注解实现
public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
super.onStartup(servletContext);
// 添加filter
FilterRegistration.Dynamic encodingFilter = servletContext.addFilter("CharacterEncodingFilter", new CharacterEncodingFilter("UTF-8"));
encodingFilter.addMappingForUrlPatterns(null, false, "/*");
}
}
8、 MultipartResolver
注解实现
xml
的实现方式
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="UTF-8"/>
<property name="maxInMemorySize" value="20480"/>
</bean>
注解的实现方式
@Bean
public CommonsMultipartResolver multipartResolver() {
CommonsMultipartResolver resolver = new CommonsMultipartResolver();
resolver.setDefaultEncoding("UTF-8");
return resolver;
}
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