1.处理JSON
Json : 是一种数据交换格式, { key: value } JSON 对象, [ ] JSON 数组。
因为Json这种数据格式在页面方便解析xml : 是一种数据交换格式 ,xml 数据交换格式很强大,但是页面不方便解析, 需要DOM编程基础,所有往往xml用于配置文件来使用
JSON工具 :使用第三的JSON 工具来处理: fastjson 、 gson 、 jackson 等都是常用的一些json处理工具
Springmvc 处理 json : Springmvc 默认支持 jackson 工具,在处理json数据的时候,不需要显示的调用jackson工具提供的API,只需要学习两个注解方可完成 json 转换
@ResponseBody : 可以把java 对象转换成json格式的字符串
@RequestBody :可以把json格式的字符串 转换成java 对象导入 jackson 的依赖
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.1.0</version>
</dependency>
2.文件上传
文件上传 : apache 提供的 File-upload.jar 、 commons-io.jar Springmvc 框架要做文件上传,也需要以上的两个包
准备工作 :
1.导入File-upload.jar 、 commons-io.jar包
2.配置一个多部件表单处理解析器(springmvc的配置文件中配置)
<!--该组件的id 必须是 multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>
3.编写文件上传的页面,注意问题的是,文件上传要 通过form 标签来完成,还要修改表单中的 enctype="multipart/form-data",还要注意提交方式一 定要为POST
- Controller 组件使用 MultipartFile 类型来接收文件数据
3.SpringMVC 拦截器
- 拦截器:凡是表现层的框架(struts2 、 springmvc)都定义了属于自己规范的拦截器。只能拦截Action (Controller,Handler)动作请求。
- 过滤器:Filter它是sun公司定义的一套规范,可以拦截所有的资源请求的。
- 方便用于自定义拦截器,各个框架都提供了接口规范:
Struts2 提供了(Interceptor) abstractInterceptor 抽象类,定义拦截器。
Springmvc 提供了HandlerInterceptor 接口, 定义拦截器。
3.1 自定义拦截器
- 自定义拦截器类
/**
* 1.自定义了一个拦截器类
* 2.自定义拦截器放入容器中 (告诉框架配了一个拦截器)
* 3.定义拦截的资源
*
*/
@Component(value="my1")
public class MyInterceptor implements HandlerInterceptor {
//处理请求的方法,preHandle,如果返回false 表示不放行,返回true 放行 ,handler 该参数拦截的方法(HandlerMethod)
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("springmvc 拦截器拦截了...");
if(handler instanceof HandlerMethod) {
HandlerMethod hm = (HandlerMethod)handler;
System.out.println(hm.getMethod().getName());
}
return true;
}
//在拦截方法执行完毕后,才执行,视图还没有被解析,可以获得modelandveiw
public void postHandle(HttpServletRequest request,HttpServletResponse response, Object handler,ModelAndView modelAndView) throws Exception {
System.out.println("postHandle....执行了");
System.out.println(modelAndView);
modelAndView.setViewName("main");
}
//在视图解析完毕后,执行的
public void afterCompletion(HttpServletRequest request,HttpServletResponse response, Object handler, Exception ex)
throws Exception {
System.out.println("afterCompletion");
}
}
- 放入 容器
@Component(value="my1")
public class MyInterceptor implements HandlerInterceptor {
- 配置拦截规则
<!-- 定义拦截器拦截的规则 -->
<mvc:interceptors>
<mvc:interceptor>
<!-- 定义拦截的资源 -->
<mvc:mapping path="/**"/>
<!-- 定义不拦截的资源 -->
<mvc:exclude-mapping path="/m3"/>
<!-- 定义拦截的拦截器 -->
<ref bean="my1"/>
</mvc:interceptor>
</mvc:interceptors>
4.SpringMVC 全局异常处理器
4.1 分析SpringMVC内部异常处理流程:
4.2 编写全局异常处理器步骤
编写自定义异常处理类,实现HandlerExceptionResolver
告诉springmvc自定义的异常处理器:很简单只需要把自定义的异常处理器在springmvc容器中配置下
编写自定义异常处理类,实现HandlerExceptionResolver
public class GlobleExceptionResolver implements HandlerExceptionResolver {
@Override
public ModelAndView resolveException(HttpServletRequest request,
HttpServletResponse response, Object handler, Exception ex) {
String error = "";
if(ex instanceof DaoException) {
error = "数据持久化操作失败,请检查再试下";
}else {
error = "系统未知异常,请联系管理员";
}
ModelAndView modelAndView = new ModelAndView();
//保存错误信息
modelAndView.addObject("error", error);
modelAndView.setViewName("error"); //指定错误页面
return modelAndView;
}
}
5. SSM (springmvc spring mybatis)整合
- 配置 pom 文件
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.xingxue.ssm</groupId>
<artifactId>ssm</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<!-- spring 相关的依赖 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.0.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.0.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>4.0.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.0.4.RELEASE</version>
</dependency>
<!-- spring web 模块提供了启动 spring 容器的 监听器 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.0.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.0.4.RELEASE</version>
</dependency>
<!-- mybatis相关的依赖 start -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.2.3</version>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>2.2.2</version>
</dependency>
<!-- mybatis 整合 spring的依赖插件 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.1</version>
</dependency>
<!-- mybatis相关的依赖 end -->
<!-- spring end -->
<!-- ======================以下是可选的依赖================================ -->
<!-- 导入mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
<!-- servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
</dependency>
<!-- jsp-api -->
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.2.1</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.21</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.29</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
<configuration>
<target>1.7</target>
<source>1.7</source>
</configuration>
</plugin>
</plugins>
</build>
</project>
- 配置 web.xml 文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<!-- 配置 spring 提供的 POST 提交方式的 中文乱码过滤器 CharacterEncodingFilter-->
<filter>
<filter-name>cef</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>cef</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- springmvc 的中央控制器 -->
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<!-- 会创建 子 容器 -->
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<!-- 该监听器创建一个 父容器 -->
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
</web-app>
- 父容器的 xml 配置
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.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">
<!-- 读取外部的 properties 文件,到内存 -->
<context:property-placeholder location="classpath:jdbc.properties"/>
<context:component-scan base-package="com.xingxue" use-default-filters="false">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Service"/>
<context:include-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!-- SqlSessionFactory 工厂交给容器管理 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="mapperLocations" value="classpath:com/xingxue/ssm/mapper/*Mapper.xml"></property>
</bean>
<!-- 配置 druid 数据源 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="username" value="${jdbc.user}"></property>
<property name="password" value="${jdbc.password}"></property>
<property name="url" value="${jdbc.url}"></property>
<property name="driverClassName" value="${jdbc.driver}"></property>
</bean>
<!-- 配置 mapper 接口的代理实现类 -->
<mybatis-spring:scan base-package="com.xingxue.ssm.mapper"/>
<!-- =============以下是配置事务管理=============== -->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
</beans>
- 子容器 xml 配置
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.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">
<mvc:default-servlet-handler />
<context:component-scan base-package="com.xingxue" use-default-filters="false">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/>
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
</context:component-scan>
<mvc:annotation-driven />
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>