2019年3月springboot最新面试题(含详细答案)

备注:以上外部文件属性加载.切记注意中文乱码问题.

9.springboot支持的默认日志框架有哪些.可以进行哪些设置.

spring-boot: 默认采用Logback作为日志框架.
配置即可:
logging.file=d:/test/log.log
logging.level.org.springframework.web=DEBUG
#logging.config=classpath:logback.xml 加载单独的日志配置文件.
其他配置项......

10.springboot项目的开发环境,生产环境配置该如何实现切换.

        profile配置:
spring-boot默认为了支持不同的配置环境.
配置步骤: 1.提供环境:
    按照命名模板:application-{profile}.properties(例如: application-pro1.properties/application-pro2.properties)
    2.选择激活的环境:
    application.properties中设置:spring.profiles.active=pro1

springboot项目WEB模块开发面试题(二)

11.什么是springboot项目中的自动配置与手动配置.如果需要手动配置该如何实现.

        自动配置: boot项目默认支持很多框架的集成. 添加组件即可. 只需要: 针对application.properties做出自动配置的属性重写即可完成.默认开启.
        举例:
         spring boot 采用自动配置集成freemarker模板引擎:(超级简单)
        前提: 构建spring boot项目.
        1.引入模板组件.
        <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
        2.编写Controller和freemarker模板.位于resources/templates.

        手动配置: 手动自定义web组件,代替boot项目默认支持的组件与配置.
        举例:
        采用手动配置参数,集成freemarker模板引擎.
        1.前提: spring-boot-starter-web .引入.
        2.编写过程类似于springMVC.
        3.额外的SpringMVC的容器配置:
        默认基于spring boot的基本默认配置即可(需要修改: 位于application.properties).
        需要手动编写类似于spring容器可以:
        @Configuration
        Public class MVCConfiguration extends WebMvcConfigurerAdapter{ 

        //视图解析器默认地址为: /resources , /static , /templates, /public,/META
        @Bean
                public InternalResourceViewResolver defaultResolver(){
                        InternalResourceViewResolver resourceViewResolver = new InternalResourceViewResolver();
                        resourceViewResolver.setPrefix("classpath:/templates/");
                        resourceViewResolver.setSuffix(".html");
                        return resourceViewResolver;
                }

        //解析视图时,默认从以上地址中依次寻找视图资源加载,如果自定义例如Freemarker模板视图解析器的资源地址,那么:
        @Bean
                public FreeMarkerViewResolver defaultResolver(){
                        FreeMarkerViewResolver freeMarkerViewResolver = new FreeMarkerViewResolver();
        //      freeMarkerViewResolver.setPrefix("classpath:/views/");
                        freeMarkerViewResolver.setSuffix(".html");
                        freeMarkerViewResolver.setContentType("text/html;charset=utf-8");
                        return freeMarkerViewResolver;
                }

                @Bean
                public FreeMarkerConfigurer freeMarkerConfigurer(){
                        FreeMarkerConfigurer configurer = new FreeMarkerConfigurer();
                        configurer.setTemplateLoaderPaths("classpath:/views/");
                        configurer.setDefaultEncoding("utf-8");
                        return configurer;
                }

        //如果不设置静态资源目录,默认: classpath: /static/  ,  classpath: /public/  ,  classpath: /resources/  ,  classpath: /META-INF/resources/
                @Override
                public void addResourceHandlers(ResourceHandlerRegistry registry) {
                     registry.addResourceHandler("/image/**").addResourceLocations("classpath:/static/image/");
                        registry.addResourceHandler("/css/**").addResourceLocations("classpath:/static/css/");
                        registry.addResourceHandler("/js/**").addResourceLocations("classpath:/static/js/");
                }

        }
        以上手动配置总结: 如果想要完全自定义,接管spring boot中的所有web配置,可以:
        @Configuration: 创建mvc适配器子类的对象.  并绑定至spring容器中.
        @EnableWebMvc: 扫描spring容器中的mvc适配器子类对象.
        Public class MVCConfiguration extends WebMvcConfigurerAdapter{ 重写方法即可. }

12.springboot项目web开发时如何集成web组件:servlet.filter.listener.

                前提: 自定义servlet(实现或继承HttpServlet),filter(实现或继承Filter),listener(实现或继承ServletContextListener).
                方式一: 将以下组件直接提供在main()启动类中.用于加载.
                @Bean
                public ServletRegistrationBean servletRegistrationBean() {
                    return new ServletRegistrationBean(new CustomServlet(), "/custom");
                }

                @Bean
                public FilterRegistrationBean filterRegistrationBean() {
                    return new FilterRegistrationBean(new CustomFilter(), servletRegistrationBean());
                }

                @Bean
                public ServletListenerRegistrationBean<CustomListener> servletListenerRegistrationBean() {
                    return new ServletListenerRegistrationBean<CustomListener>(new CustomListener());
                }
                方式二: 启动类 实现ServletContextInitializer .重写onStartup().
                @SpringBootApplication
                public class SpringBootDemo102Application implements ServletContextInitializer {

                    @Override
                    public void onStartup(ServletContext servletContext) throws ServletException {
                        servletContext.addServlet("customServlet", new CustomServlet()).addMapping("/custom");
                        servletContext.addFilter("customFilter", new CustomFilter())
                                .addMappingForServletNames(EnumSet.of(DispatcherType.REQUEST), true, "customServlet");
                        servletContext.addListener(new CustomListener());
                    }
                }

                方式三:启动类开启扫描: @ServletComponentScan
                工具组件采用注解进行加载:
                @WebFilter(filterName = "customFilter", urlPatterns = "/*")
                @WebListener
                @WebServlet(name = "customServlet", urlPatterns = "/custom")

13.springboot+springmvc如何实现集成( 视图模板: 基于JSP).官方不推荐,但工作有需求.

                1.引入pom.xml组件:
                <dependency>
                            <groupId>org.springframework.boot</groupId>
                            <artifactId>spring-boot-starter-tomcat</artifactId>
                </dependency>
                <dependency>
                         <groupId>org.apache.tomcat.embed</groupId>
                         <artifactId>tomcat-embed-jasper</artifactId>
                </dependency>
                <dependency>
                    <groupId>javax.servlet</groupId>
                    <artifactId>javax.servlet-api</artifactId>
                </dependency>
                <dependency>
                    <groupId>javax.servlet</groupId>
                    <artifactId>jstl</artifactId>
                </dependency>

                2. 增加application.properties配置:
                #?页面默认前缀目录
                spring.mvc.view.prefix=/WEB-INF/jsp/
                #?响应页面默认后缀
                spring.mvc.view.suffix=.jsp
                #静态资源目录配置,
                spring.mvc.static-path-pattern=/static/**

                3.编写controller和jsp: 测试即可.
                (jsp页面中可直接请求${pageContext.request.contextPath}.)

                补充: src/main/webapp/WEB-INF 创建该目录.用于存储页面资源等.
                右击项目--->Modules----> web(springboot无需xml. 指定webapp目录为资源根目录.) 并create artifacts ---> apply.即可

14.springboot+mybatis如何实现集成.(注意: 官方默认支持的spring-data框架不在此处介绍.)

                        步骤一: 填充pom.xml:
                                <dependency>
                                        <groupId>org.mybatis.spring.boot</groupId>
                                        <artifactId>mybatis-spring-boot-starter</artifactId>
                                        <version>1.3.2</version>
                                </dependency>

                                <dependency>
                                        <groupId>commons-dbcp</groupId>
                                        <artifactId>commons-dbcp</artifactId>
                                        <version>1.4</version>
                                </dependency>

                                <dependency>
                                        <groupId>org.springframework.boot</groupId>
                                        <artifactId>spring-boot-starter-jdbc</artifactId>
                                </dependency>

                                <dependency>
                                        <groupId>mysql</groupId>
                                        <artifactId>mysql-connector-java</artifactId>
                                        <version>5.1.40</version>
                                </dependency>

                                步骤二: application.properties
                                spring.datasource.driver-class-name=com.mysql.jdbc.Driver
                                spring.datasource.url=jdbc:mysql://localhost:3306/c01?useUnicode=true&characterEncoding=utf-8
                                spring.datasource.username=root
                                spring.datasource.password=root
                                spring.datasource.type=org.apache.commons.dbcp.BasicDataSource

                                mybatis.mapper-locations=classpath:mapper/*_mapper.xml
                                步骤三: com.hfxt.demo1.dao.UserDao
                                public interface UserDao {
                                        @ResultMap("BaseResultMap")
                                        @Select("select * from tb_book")
                                        List<User> selectAll(User u1);
                                }
                                步骤四: resources/mapper/User_mapper.xml
                                <?xml version="1.0" encoding="UTF-8"?>
                                <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
                                <mapper namespace="com.hfxt.demo1.dao.UserDao">
                                        <resultMap id="BaseResultMap" type="com.hfxt.demo1.domain.User">
                                                <id column="id" jdbcType="INTEGER" property="id"/>
                                                <result column="book_name" jdbcType="VARCHAR" property="bookName"/>
                                                <result column="book_price" jdbcType="VARCHAR" property="bookPrice"/>
                                        </resultMap>
                                </mapper>
                                步骤五: spring容器扫描接口.
                                @SpringBootApplication
                                @MapperScan("com.hfxt.demo1.dao")
                                public class Demo1Application { }
                                步骤六: 注入dao到service中.
                                //    @Resource
                                        @Autowired
                                        private UserDao userDao;

15.springboot项目的常用启动部署方式有哪些.

        1.启动main主函数即可.
        2.采用maven插件的启动方式:新建maven启动方式,并明确working directory为项目根目录. Command Line为 spring-boot:run 即可ok启动.  该方式必须为标准的tomcat容器.
        3.生产环境下的部署启动方式:
        实际项目部署: 切换至父项目pom.xml根目录中, mvn install package 打包. 将target中生成的war包项目部署至tomcat/webapp中,直接启动tomcat即可. 注意:JAVA_HOME要设置为1.8 因为springboot2.0 必须至少jdk环境为1.8.

补充: 以上springboot项目的公共配置属性清单地址如下: