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Spring4+Spring MVC+MyBatis整合思路

1、Spring框架的搭建

這個很簡單,只需要web容器中註冊org.springframework.web.context.ContextLoaderListener,並指定spring載入配置檔案,那麼spring容器搭建完成。(當然org.springframework的核心jar包需要引入)

當然為了更加易用支援J2EE應用,一般我們還會加上如下:

Spring監聽HTTP請求事件:org.springframework.web.context.request.RequestContextListener

<!-- spring配置檔案開始 -->
	<context-param>
		<param-name>contextConfigLocation</param-name><!-- spring配置檔案,請根據需要選取 -->
		<param-value>classpath*:webconfig/service-all.xml</param-value>
	</context-param>
	<listener><!-- Spring負責監聽web容器啟動和關閉的事件 --><!-- Spring ApplicationContext載入 -->
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
	<listener><!-- Spring監聽HTTP請求事件 -->
		<!-- 使spring支援request與session的scope,如: -->
		<!-- <bean id="loginAction" class="com.foo.LoginAction" scope="request"/> -->
		<!-- 使用: -->
		<!-- 1、註解獲取:@Autowired HttpServletRequest request; -->
		<!-- 2、java程式碼:HttpServletRequest request = 
		((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest(); -->
		<!-- 3、直接在引數中傳遞:public String sayHi(HttpServletRequest request) -->
		<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
	</listener>
	<listener><!-- Spring 重新整理Introspector防止記憶體洩露 -->
		<listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
	</listener>
	<filter>
		<filter-name>encodingFilter</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>
		<init-param>
			<param-name>forceEncoding</param-name>
			<param-value>false</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>encodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	<!-- spring配置檔案結束 -->

2、Spring MVC的搭建

首先我們知道Spring MVC的核心是org.springframework.web.servlet.DispatcherServlet,所以web容器中少不了它的註冊。(當然org.springframework的web、mvc包及其依賴jar包需要引入)

<!-- spring mvc配置開始 -->
	<servlet>
		<servlet-name>Spring-MVC</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath*:spring/spring-mvc.xml</param-value><!-- spring mvc配置檔案 -->
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>Spring-MVC</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>
	<!-- spring mvc配置結束 -->

同時為了更好使用MVC,spring-mvc.xml需要配置以下:

1)(可選)多部分請求解析器(MultipartResolver)配置,與上傳檔案有關 需要類庫commons-io、commons-fileupload

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
		<property name="defaultEncoding" value="utf-8"></property><!-- 預設編碼-->
		<property name="maxUploadSize" value="104857600"></property><!-- 檔案大小最大值-->
		<property name="maxInMemorySize" value="40960"></property><!-- 記憶體中的最大值-->
	</bean>

2)(可選)本地化(LocaleResolver)配置

3)(可選)主題解析器(ThemeResolver)配置 

4)(必選)處理器對映器(HandlerMapping)配置,可以配置多個,一般採用RequestMappingHandlerMapping或者自定義

這裡我們自定義了一個處理器對映器,繼承重寫RequestMappingHandlerMapping,支援@RequestMapping無需任何path引數自動裝載類名或方法作為url路徑匹配。

<bean id="handlerMapping" 
		class="io.flysium.framework.web.servlet.mvc.method.annotation.CustomHandlerMapping">
		<property name="order" value="-1" />
	</bean>

CustomHandlerMapping實現:

@Override
	protected RequestMappingInfo getMappingForMethod(Method method, Class handlerType) {
		RequestMappingInfo info = createRequestMappingInfoDefault(method);
		if (info != null) {
			RequestMappingInfo typeInfo = createRequestMappingInfoDefault(handlerType);
			if (typeInfo != null)
				info = typeInfo.combine(info);
		}
		return info;
	}

	private RequestMappingInfo createRequestMappingInfoDefault(AnnotatedElement element) {
		RequestMapping requestMapping = AnnotatedElementUtils.findMergedAnnotation(element,
				RequestMapping.class);
		RequestCondition condition = (element instanceof Class)
				? getCustomTypeCondition((Class) element)
				: getCustomMethodCondition((Method) element);
		/**
		* 以類名和方法名對映請求,參照@RequestMapping
		* 預設不需要新增任何引數(如:/className/methodName.do)
		*/
		String defaultName = (element instanceof Class)
				? ((Class) element).getSimpleName()
				: ((Method) element).getName();
		return requestMapping == null
				? null
				: createRequestMappingInfo(requestMapping, condition, defaultName);
	}

	protected RequestMappingInfo createRequestMappingInfo(RequestMapping annotation,
			RequestCondition<?> customCondition, String defaultName) {
		String[] patterns = resolveEmbeddedValuesInPatterns(annotation.value());
		if (patterns != null && (patterns.length == 0)) {
			patterns = new String[]{defaultName};
		}
		return new RequestMappingInfo(
				new PatternsRequestCondition(patterns, getUrlPathHelper(), getPathMatcher(),
						this.useSuffixPatternMatch, this.useTrailingSlashMatch,
						this.fileExtensions),
				new RequestMethodsRequestCondition(annotation.method()),
				new ParamsRequestCondition(annotation.params()),
				new HeadersRequestCondition(annotation.headers()),
				new ConsumesRequestCondition(annotation.consumes(), annotation.headers()),
				new ProducesRequestCondition(annotation.produces(), annotation.headers(),
						this.contentNegotiationManager),
				customCondition);
	}

5)(必選)處理器介面卡(HandlerAdapter)配置,可以配置多個,主要是配置messageConverters,其主要作用是對映前臺傳參與handler處理方法引數。一般擴充套件RequestMappingHandlerAdapter,或者自定義。如果我們需要json請求的處理,這裡必須擴充套件。同時我們需要注意的是日期格式的轉換。

另外Spring 4.2新特性,加之註解會自動注入@ControllerAdvice,可以定義RequestBodyAdvice、ResponseBodyAdvice,可以更方便地在引數處理方面著手自定義。

<bean id="handlerAdapter"
	class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
	<property name="order" value="-1" />
	<property name="messageConverters">
		<list>
		<!-- <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" 
			/> -->
			<ref bean="mappingJacksonHttpMessageConverter" />
		</list>
	</property>
	<property name="webBindingInitializer">
		<bean
			class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">
			<property name="conversionService">
				<!-- 針對普通請求(非application/json) 前臺的日期字串與後臺的Java Date物件轉化,
				此情況,應使用spring 
					mvc本身的內建日期處理 -->
				<!-- 可以在VO屬性上加註解:@DateTimeFormat 需要類庫joda-time -->
		<bean
		class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
		</bean>
			</property>
		</bean>
	</property>
</bean>
<!-- json請求(application/json)返回值Date轉String,全域性配置 -->
<bean name="jacksonObjectMapper"
	class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
	<property name="featuresToDisable">
		<array>
		<util:constant
static-field="com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS" />
		</array>
	</property>
	<!-- 如果想自定義,可以在VO屬性上加註解:@JsonFormat(shape = JsonFormat.Shape.STRING, pattern 
		= Consts.DATE_PATTERN.DATE_PATTERN_OBLIQUE,timezone = "GMT+8") -->
	<property name="simpleDateFormat">
		<value>yyyy-MM-dd HH:mm:ss</value>
	</property>
</bean>
<!--避免IE執行Ajax時,返回JSON出現下載檔案 -->
<!-- 自定義 -->
<bean id="mappingJacksonHttpMessageConverter"
	class="io.flysium.framework.http.converter.json.CustomJackson2HttpMessageConverter">
	<property name="objectMapper" ref="jacksonObjectMapper" />
	<property name="supportedMediaTypes">
		<list>
			<value>text/html;charset=UTF-8</value>
			<value>application/json;charset=UTF-8</value>
		</list>
	</property>
</bean>

6)(可選)處理器異常解析器(HandlerExceptionResolver)配置,可以配置多個,配置Controller異常丟擲後,我們是怎麼樣處理的,一般需要日誌或做反饋的可以自定義。

7)(可選)請求到檢視名翻譯器(RequestToViewNameTranslator)配置,RequestToViewNameTranslator可以在處理器返回的View為空時使用它根據Request獲得viewName。

8)(可選)檢視解析器(ViewResolver)配置,可以配置多個,定義跳轉的檔案的前後綴 ,檢視模式配置,主要針對@Controller返回ModelAndView的檢視路徑解析,動給後面控制器的方法return的字串 加上字首和字尾,變成一個 可用的url地址 。

<bean id="viewResolver"
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/" />
		<property name="suffix" value=".jsp" />
		<property name="viewClass"
			value="org.springframework.web.servlet.view.JstlView" />
	</bean>

最後給Controller加入元件掃描吧,這樣減少xml配置,直接在Java程式碼中加入註解即可。

    <!-- 自動掃描類包,將標誌Spring註解的類自動轉化為Bean,同時完成Bean的注入 -->
	<!-- 掃描控制器 -->
	<context:component-scan base-package="io.flysium" use-default-filters="false">
		<context:include-filter type="annotation" 
			expression="org.springframework.stereotype.Controller" />
		<context:include-filter type="annotation" 
			expression="org.springframework.web.bind.annotation.RestController" />
		<context:include-filter type="annotation" 
			expression="org.springframework.web.bind.annotation.ControllerAdvice" />
	</context:component-scan>

3、Mybatis整合

整合mybatis到Spring框架,我們需要mybatis的jar包,及mybatis-spring整合jar包。然後在Spring容器中註冊配置org.mybatis.spring.SqlSessionFactoryBean(需要資料來源,及指定Mybatis配置檔案)及org.mybatis.spring.SqlSessionTemplate即可。

更多整合請參照Git專案:https://git.oschina.net/svenaugustus/app-ss4m-less

目前除了ssm,另外整合redis(支援切換單節點配置、主從哨兵配置,叢集配置)、spring session方案。

其中包括spring MVC的簡單demo,用於學習交流。