Spring Boot 常用配置

WebMVC配置

1、自定义消息转换器

2、自定义拦截器

3、自定义静态资源访问转发

全局异常处理

自定义Servlet组件、Filter过滤器和Listener监听器

Mybatis-Plus分页插件

开启指标监控

配置类

本文主要记录再spring boot项目中常用的一些配置

WebMVC配置

首先需要创建一个配置类标注@configuration注解，并注入WebMvcConfigure这个组件

@Configuration
public class MyConfig {

    @Bean
    public WebMvcConfigurer webMvcConfigurer(){
        return new WebMvcConfigurer() {
        }
    }
}

1、自定义消息转换器

先编写一个实体类User和一个自定义消息转换器实现HttpMessageConverte

@Data
public class User {

    private String id;

    private String userName;

    private String sex;

    private String birth;
}

public class MyMessageConverter implements HttpMessageConverter {
    @Override
    public boolean canRead(Class aClass, MediaType mediaType) {
        return false;
    }

    @Override
    public boolean canWrite(Class aClass, MediaType mediaType) {
        // 如果传入的是User对象就可以写
        return aClass.isAssignableFrom(User.class);
    }

    // 服务器要统计所有的MessageConverters支持的内容类型 canWrite返回true就会进入该方法
    @Override
    public List getSupportedMediaTypes() {
        return MediaType.parseMediaTypes("application/lzz-mc");
    }

    @Override
    public User read(Class aClass, HttpInputMessage httpInputMessage) throws IOException, HttpMessageNotReadableException {
        return null;
    }

    // 自定义协议数据的写出 User对象的属性-->User对象属性的值
    @Override
    public void write(User user, MediaType mediaType, HttpOutputMessage httpOutputMessage) throws IOException, HttpMessageNotWritableException {
        Field[] fields = user.getClass().getDeclaredFields();
        StringBuilder stringBuilder = new StringBuilder();
        for (Field field : fields) {
            field.setAccessible(true);
            String name = field.getName();
            try {
                Object o = field.get(user);
                stringBuilder.append(name).append(" --> ").append(o.toString()).append("n");
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }

        OutputStream body = httpOutputMessage.getBody();
        body.write(stringBuilder.toString().getBytes());

    }
}

在配置类中添加这个自定义消息转换器

 @Override
 public void extendMessageConverters(List> converters) {
     converters.add(new MyMessageConverter());
}

此时测试时在controller中编写一个根据id获取user的请求，返回user对象，其中controller需要标注@RestController注解

    @GetMapping("user/{id}")
    public User get(@PathVariable String id){
        User user = new User();
        user.setId(id);
        user.setUserName("liuzhuzheng");
        user.setSex("boy");
        user.setBirth("1999-12-03");
        return user;
    }

用postman测试更改accept接收的返回数据格式为我们自定义的内容类型返回结果就会进入我们自定义的消息转换器调用write方法输出其中的原理用到了springboot的内容协商

如果需要在网页上调用请求需要在yml文件中进行如下设置

spring:
  mvc:
    contentnegotiation:
      favor-parameter: true #开启请求参数内容协商模式 通过在queryString上添加format字段

并在配置文件中添加内容协商配置

            @Override
            public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
                // 指定参数对应的媒体类型
                Map mediaTypes = new HashMap<>();
                mediaTypes.put("json",MediaType.APPLICATION_JSON);
                mediaTypes.put("xml",MediaType.APPLICATION_XML);
                mediaTypes.put("lzz",MediaType.parseMediaType("application/lzz-mc"));

                // 设置参数内容协商策略
                ParameterContentNegotiationStrategy parameterContentNegotiationStrategy = new ParameterContentNegotiationStrategy(mediaTypes);
                // 设置参数名 默认format
                parameterContentNegotiationStrategy.setParameterName("type");

                // 设置请求头内容协商策略
                HeaderContentNegotiationStrategy headerContentNegotiationStrategy = new HeaderContentNegotiationStrategy();

                configurer.strategies(Arrays.asList(parameterContentNegotiationStrategy,headerContentNegotiationStrategy));
            }

最终测试如下

2、自定义拦截器

先创建拦截器类实现HandleInterceptor

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

在配置类中添加拦截器

            @Override
            public void addInterceptors(InterceptorRegistry registry) {
                registry.addInterceptor(new MyInterceptor())
                        .addPathPatterns("
            @Override
            public void addResourceHandlers(ResourceHandlerRegistry registry) {
                registry.addResourceHandler("/sta
@ControllerAdvice
public class GlobalExceptionHandle {

    @ExceptionHandler({ArithmeticException.class,NullPointerException.class})
    public String globalHandleException(Exception e){
        
        return "我的异常处理";
    }
}

自定义Servlet组件、Filter过滤器和Listener监听器

创建自定义servlet类实现HttpServlet

@WebServlet(urlPatterns = "/servlet")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("myServlet");
        //super.doGet(req, resp);
    }

//    @Override
//    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        super.doPost(req, resp);
//    }
}

创建自定义filter实现FIlter

@WebFilter(urlPatterns = "/filter")
@Slf4j
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("myFilter初始化");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        log.info("myFilter工作中");
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {
        log.info("myFilter已销毁");
    }
}

创建自定义listener实现ServletContextListener

@WebListener
@Slf4j
public class MyListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        log.info("listener初始化");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        log.info("listener已销毁");
    }
}

配置类中注册这些组件

    
    @Bean
    public ServletRegistrationBean myServlet(){
        MyServlet myServlet = new MyServlet();
        return new ServletRegistrationBean<>(myServlet,"/servlet","/myServlet");
    }

    
    @Bean
    public FilterRegistrationBean myFilter(){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean<>(new MyFilter());
        filterRegistrationBean.addUrlPatterns("/filter","/myFilter");
        return filterRegistrationBean;
    }

    
    @Bean
    public ServletListenerRegistrationBean myListener(){
        MyListener myListener = new MyListener();
        return new ServletListenerRegistrationBean<>(myListener);
    }

Mybatis-Plus分页插件

前提是在使用mybatis-plus，并引入了依赖

        
            com.baomidou
            mybatis-plus-boot-starter
            3.4.3

配置类中添加

    
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();

        PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
        paginationInnerInterceptor.setDbType(DbType.H2);
        paginationInnerInterceptor.setOverflow(true);
        paginationInnerInterceptor.setMaxLimit(200L);

        mybatisPlusInterceptor.addInnerInterceptor(paginationInnerInterceptor);

        return mybatisPlusInterceptor;
    }

开启指标监控

前提是引入了依赖进行指标监控

        
            org.springframework.boot
            spring-boot-starter-actuator

在yml文件中进行配置

management:
  endpoints:
    web:
      exposure:
        include: '*' #开启所有endpoint可通过web方式访问

  endpoint:
    health:
      show-details: always #展示health监控状态详细信息

浏览器测试,都是以http://localhost:8080/actuator/开头，后面接具体的指标

配置类

整个配置类的内容如下

package com.example.demo.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import com.example.demo.config.converter.MyMessageConverter;
import com.example.demo.config.interceptor.MyInterceptor;
import com.example.demo.config.servlet.MyFilter;
import com.example.demo.config.servlet.MyListener;
import com.example.demo.config.servlet.MyServlet;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.web.accept.HeaderContentNegotiationStrategy;
import org.springframework.web.accept.ParameterContentNegotiationStrategy;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


@Configuration
public class MyConfig {

    @Bean
    public WebMvcConfigurer webMvcConfigurer(){
        return new WebMvcConfigurer() {

            
            @Override
            public void extendMessageConverters(List> converters) {
                converters.add(new MyMessageConverter());
            }

            
            @Override
            public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
                // 指定参数对应的媒体类型
                Map mediaTypes = new HashMap<>();
                mediaTypes.put("json",MediaType.APPLICATION_JSON);
                mediaTypes.put("xml",MediaType.APPLICATION_XML);
                mediaTypes.put("lzz",MediaType.parseMediaType("application/lzz-mc"));

                // 设置参数内容协商策略
                ParameterContentNegotiationStrategy parameterContentNegotiationStrategy = new ParameterContentNegotiationStrategy(mediaTypes);
                // 设置参数名 默认format
                parameterContentNegotiationStrategy.setParameterName("type");

                // 设置请求头内容协商策略
                HeaderContentNegotiationStrategy headerContentNegotiationStrategy = new HeaderContentNegotiationStrategy();

                configurer.strategies(Arrays.asList(parameterContentNegotiationStrategy,headerContentNegotiationStrategy));
            }

            
            @Override
            public void addInterceptors(InterceptorRegistry registry) {
                registry.addInterceptor(new MyInterceptor())
                        .addPathPatterns("
            @Override
            public void addResourceHandlers(ResourceHandlerRegistry registry) {
                registry.addResourceHandler("/sta
    @Bean
    public ServletRegistrationBean myServlet(){
        MyServlet myServlet = new MyServlet();
        return new ServletRegistrationBean<>(myServlet,"/servlet","/myServlet");
    }

    
    @Bean
    public FilterRegistrationBean myFilter(){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean<>(new MyFilter());
        filterRegistrationBean.addUrlPatterns("/filter","/myFilter");
        return filterRegistrationBean;
    }

    
    @Bean
    public ServletListenerRegistrationBean myListener(){
        MyListener myListener = new MyListener();
        return new ServletListenerRegistrationBean<>(myListener);
    }

    
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();

        PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
        paginationInnerInterceptor.setDbType(DbType.H2);
        paginationInnerInterceptor.setOverflow(true);
        paginationInnerInterceptor.setMaxLimit(200L);

        mybatisPlusInterceptor.addInnerInterceptor(paginationInnerInterceptor);

        return mybatisPlusInterceptor;
    }
}

Spring Boot 常用配置

WebMVC配置 首先需要创建一个配置类标注@configuration注解，并注入WebMvcConfigure这个组件 @Configuration public class MyConfig { @Bean public WebMvcConfigurer webMvcConfigurer(){ return new WebMvcConfigurer() { } } }

Java相关栏目本月热门文章

WebMVC配置
首先需要创建一个配置类标注@configuration注解，并注入WebMvcConfigure这个组件

@Configuration public class MyConfig { @Bean public WebMvcConfigurer webMvcConfigurer(){ return new WebMvcConfigurer() { } } }