Spring4 + Spring MVC + MyBatis 整合思路

Java框架

浏览数:1,406

2018-3-18

1、Spring框架的搭建

这个很简单,只需要web容器中注册org.springframework.web.context.ContextLoaderListener,并指定spring加载配置文件,那么spring容器搭建完成。(当然org.springframework的核心jar包需要引入)

当然为了更加易用支持J2EE应用,一般我们还会加上如下:

Spring监听HTTP请求事件:org.springframework.web.context.request.RequestContextListener

<!-- spring配置文件开始 -->
    <context-param>
        <param-name>contextConfigLocation</param-name><!-- spring配置文件,请根据需要选取 -->
        <param-value>classpath*:webconfig/service-all.xml</param-value>
    </context-param>
    <listener><!-- Spring负责监听web容器启动和关闭的事件 --><!-- Spring ApplicationContext载入 -->
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <listener><!-- Spring监听HTTP请求事件 -->
        <!-- 使spring支持request与session的scope,如: -->
        <!-- <bean id="loginAction" class="com.foo.LoginAction" scope="request"/> -->
        <!-- 使用: -->
        <!-- 1、注解获取:@Autowired HttpServletRequest request; -->
        <!-- 2、java代码:HttpServletRequest request = 
        ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest(); -->
        <!-- 3、直接在参数中传递:public String sayHi(HttpServletRequest request) -->
        <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
    </listener>
    <listener><!-- Spring 刷新Introspector防止内存泄露 -->
        <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配置文件结束 -->

2、Spring MVC的搭建

首先我们知道Spring MVC的核心是org.springframework.web.servlet.DispatcherServlet,所以web容器中少不了它的注册。(当然org.springframework的web、mvc包及其依赖jar包需要引入)

<!-- spring mvc配置开始 -->
    <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配置文件 -->
        </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配置结束 -->

同时为了更好使用MVC,spring-mvc.xml需要配置以下:

1)(可选)多部分请求解析器(MultipartResolver)配置,与上传文件有关 需要类库commons-io、commons-fileupload

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="defaultEncoding" value="utf-8"></property><!-- 默认编码-->
        <property name="maxUploadSize" value="104857600"></property><!-- 文件大小最大值-->
        <property name="maxInMemorySize" value="40960"></property><!-- 内存中的最大值-->
    </bean>

2)(可选)本地化(LocaleResolver)配置

3)(可选)主题解析器(ThemeResolver)配置

4)(必选)处理器映射器(HandlerMapping)配置,可以配置多个,一般采用RequestMappingHandlerMapping或者自定义

这里我们自定义了一个处理器映射器,继承重写RequestMappingHandlerMapping,支持@RequestMapping无需任何path参数自动装载类名或方法作为url路径匹配。

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

CustomHandlerMapping实现:

@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);
        /**
        * 以类名和方法名映射请求,参照@RequestMapping
        * 默认不需要添加任何参数(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)(必选)处理器适配器(HandlerAdapter)配置,可以配置多个,主要是配置messageConverters,其主要作用是映射前台传参与handler处理方法参数。一般扩展RequestMappingHandlerAdapter,或者自定义。如果我们需要json请求的处理,这里必须扩展。同时我们需要注意的是日期格式的转换。

另外Spring 4.2新特性,加之注解会自动注入@ControllerAdvice,可以定义RequestBodyAdvice、ResponseBodyAdvice,可以更方便地在参数处理方面着手自定义。

<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">
                <!-- 针对普通请求(非application/json) 前台的日期字符串与后台的Java Date对象转化,
                此情况,应使用spring 
                    mvc本身的内置日期处理 -->
                <!-- 可以在VO属性上加注解:@DateTimeFormat 需要类库joda-time -->
        <bean
        class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        </bean>
            </property>
        </bean>
    </property>
</bean>
<!-- json请求(application/json)返回值Date转String,全局配置 -->
<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>
    <!-- 如果想自定义,可以在VO属性上加注解:@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执行Ajax时,返回JSON出现下载文件 -->
<!-- 自定义 -->
<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)(可选)处理器异常解析器(HandlerExceptionResolver)配置,可以配置多个,配置Controller异常抛出后,我们是怎么样处理的,一般需要日志或做反馈的可以自定义。

7)(可选)请求到视图名翻译器(RequestToViewNameTranslator)配置,RequestToViewNameTranslator可以在处理器返回的View为空时使用它根据Request获得viewName。

8)(可选)视图解析器(ViewResolver)配置,可以配置多个,定义跳转的文件的前后缀 ,视图模式配置,主要针对@Controller返回ModelAndView的视图路径解析,动给后面控制器的方法return的字符串 加上前缀和后缀,变成一个 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>

最后给Controller加入组件扫描吧,这样减少xml配置,直接在Java代码中加入注解即可。

    <!-- 自动扫描类包,将标志Spring注解的类自动转化为Bean,同时完成Bean的注入 -->
    <!-- 扫描控制器 -->
    <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,我们需要mybatis的jar包,及mybatis-spring整合jar包。然后在Spring容器中注册配置org.mybatis.spring.SqlSessionFactoryBean(需要数据源,及指定Mybatis配置文件)及org.mybatis.spring.SqlSessionTemplate即可。

 

更多整合请参照Git项目:https://git.oschina.net/svenaugustus/app-ss4m-less

目前除了ssm,另外整合redis(支持切换单节点配置、主从哨兵配置,集群配置)、spring session方案。

其中包括spring MVC的简单demo,用于学习交流。

原文地址:https://my.oschina.net/langxSpirit/blog/877396