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工具类编写

在正式开发接口前，我们还需要配置一些工具类，例如接口返回的结果集该怎么配置，对于日期该怎么处理，发生的异常该怎么处理，跨域请求怎么办等等问题。

第一步：新建 Package 

在我们的项目目录（com.qq.first_project）下新建一个 Package （common），以后我们可以将所有工具类代码都放在里面。

第二步：新建工具类代码

在该目录下新建如下工具类代码。

通用配置工具类 GlobalConfig

package com.qq.first_project.common;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.pagination.dialects.MySqlDialect;
import com.baomidou.mybatisplus.extension.plugins.pagination.optimize.JsqlParserCountOptimize;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.qq.first_project.common.DateConverter;
import com.qq.first_project.common.LocalDateTimeConverter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.List;

/**
 *
 * @ClassName: GlobalConfig
 * @Description: 通用配置
 * @author: Qiu
 */
@Configuration
public class GlobalConfig extends WebMvcConfigurationSupport {

    /**
     * 分页插件
     * @return
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        paginationInterceptor.setDialect(new MySqlDialect());
        paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
        return paginationInterceptor;
    }
    
    /**
     * spring boot 跨域过滤器
     * @return
     */
    @Bean
    FilterRegistrationBean<CorsFilter> cors(){
        FilterRegistrationBean<CorsFilter> registrationBean = new FilterRegistrationBean<CorsFilter>();
        CorsConfiguration config = new CorsConfiguration();
        
        config.setAllowCredentials(true);
        config.addAllowedOrigin("http://localhost:8120");
        config.addAllowedHeader("*");
        config.addAllowedMethod("*");
        
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", config);
        
        CorsFilter filter = new CorsFilter(source);
        registrationBean.setFilter(filter); //注册自定义过滤器
        registrationBean.addUrlPatterns("/*"); //过滤所有路径
        
        return registrationBean;
    }
    
    /**
     * springboot自定义消息转换器
     * curl http://127.0.0.1/user/getById?id=31
     * @param converters
     */
    @Override
    protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        ObjectMapper objectMapper = new ObjectMapper();
        
        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL); //忽略 null 字段
        
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
        
        objectMapper.registerModule(javaTimeModule);
        converters.add(new MappingJackson2HttpMessageConverter(objectMapper));
    }
    
    /**
     * 数据格式化
     * @param registry
     */
    @Override
    protected void addFormatters(FormatterRegistry registry) {
        super.addFormatters(registry);
        registry.addConverter(new DateConverter());
        registry.addConverter(new LocalDateTimeConverter());
    }
}

异常处理工具类 DefaultExceptionHandler

package com.qq.first_project.common;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.jdbc.BadSqlGrammarException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 *
 * @ClassName: DefaultExceptionHandler
 * @Description:异常处理
 * @author: Qiu
 */
@Slf4j
@ControllerAdvice
public class DefaultExceptionHandler {

    @ExceptionHandler(Exception.class)
    @ResponseBody
    public R error(Exception e){
        e.printStackTrace();
        return R.error();
    }

    @ExceptionHandler(BadSqlGrammarException.class)
    @ResponseBody
    public R error(BadSqlGrammarException e){
        e.printStackTrace();
        return R.setResult(ResultCode.BAD_SQL_GRAMMAR);
    }

    @ExceptionHandler(HttpMessageNotReadableException.class)
    @ResponseBody
    public R error(HttpMessageNotReadableException e){
        e.printStackTrace();
        return R.setResult(ResultCode.JSON_PARSE_ERROR);
    }
}

日期处理工具类 DateConverter 和 LocalDateTimeConverter

DateConverter 

package com.qq.first_project.common;

import org.springframework.context.annotation.Configuration;
import org.springframework.core.convert.converter.Converter;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.regex.Pattern;

/**
 *
 * @ClassName: DateConverter
 * @Description: 日期处理
 * @author: Qiu
 */
@Configuration
public class DateConverter implements Converter<String, Date> {

    public DateConverter() {
    }
    
    static List<SimpleDateFormat> sdfs = new ArrayList();
    
    static {
        sdfs.add(new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"));
        sdfs.add(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
        sdfs.add(new SimpleDateFormat("yyyy-MM-dd"));
        sdfs.add(new SimpleDateFormat("yyyy/MM/dd"));
    }
    
    @Override
    public Date convert(String s) {
        SimpleDateFormat sdf = null;
        if (Pattern.matches("^\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}$", s)) {
            sdf = sdfs.get(1);
        }else if (Pattern.matches("^\\d{4}/\\d{2}/\\d{2} \\d{2}:\\d{2}:\\d{2}$", s)){
            sdf = sdfs.get(0);
        }else if (Pattern.matches("^\\d{4}/\\d{2}/\\d{2}$", s)){
            sdf = sdfs.get(3);
        }else if (Pattern.matches("^\\d{4}-\\d{2}/-\\d{2}}$", s)){
            sdf = sdfs.get(2);
        }
        
        Date date = null;
        
        try {
            date = sdf.parse(s);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }
}

LocalDateTimeConverter

package com.qq.first_project.common;

import org.springframework.core.convert.converter.Converter;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

/**
 *
 * @ClassName: LocalDateTimeConverter
 * @Description: 日期处理 2022-03-09 11:02:03
 * @author: Qiu
 */
@Component
public class LocalDateTimeConverter implements Converter<String, LocalDateTime> {
    @Override
    public LocalDateTime convert(String s) {
        return LocalDateTime.parse(s, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
    }
}

结果集工具类 ResultCode 和 R

ResultCode

package com.qq.first_project.common;

import lombok.Getter;
import lombok.ToString;

/**
 *
 * @ClassName: ResultCode
 * @Description: 返回码
 * @author: Qiu
 */
@Getter
@ToString
public enum ResultCode {

    SUCCESS(true, 20000,"成功"),
    UNKNOWN_REASON(false, 20001, "未知错误"),

    BAD_SQL_GRAMMAR(false, 21001, "sql语法错误"),
    JSON_PARSE_ERROR(false, 21002, "json解析异常"),
    PARAM_ERROR(false, 21003, "参数不正确"),

    FILE_UPLOAD_ERROR(false, 21004, "文件上传错误"),
    FILE_DELETE_ERROR(false, 21005, "文件刪除错误"),
    EXCEL_DATA_IMPORT_ERROR(false, 21006, "Excel数据导入错误"),

    VIDEO_UPLOAD_ALIYUN_ERROR(false, 22001, "视频上传至阿里云失败"),
    VIDEO_UPLOAD_TOMCAT_ERROR(false, 22002, "视频上传至业务服务器失败"),
    VIDEO_DELETE_ALIYUN_ERROR(false, 22003, "阿里云视频文件删除失败"),
    FETCH_VIDEO_UPLOADAUTH_ERROR(false, 22004, "获取上传地址和凭证失败"),
    REFRESH_VIDEO_UPLOADAUTH_ERROR(false, 22005, "刷新上传地址和凭证失败"),
    FETCH_PLAYAUTH_ERROR(false, 22006, "获取播放凭证失败"),

    URL_ENCODE_ERROR(false, 23001, "URL编码失败"),
    ILLEGAL_CALLBACK_REQUEST_ERROR(false, 23002, "非法回调请求"),
    FETCH_ACCESSTOKEN_FAILD(false, 23003, "获取accessToken失败"),
    FETCH_USERINFO_ERROR(false, 23004, "获取用户信息失败"),
    LOGIN_ERROR(false, 23005, "登录失败"),

    COMMENT_EMPTY(false, 24006, "评论内容必须填写"),

    PAY_RUN(false, 25000, "支付中"),
    PAY_UNIFIEDORDER_ERROR(false, 25001, "统一下单错误"),
    PAY_ORDERQUERY_ERROR(false, 25002, "查询支付结果错误"),

    ORDER_EXIST_ERROR(false, 25003, "课程已购买"),

    GATEWAY_ERROR(false, 26000, "服务不能访问"),

    CODE_ERROR(false, 28000, "验证码错误"),

    LOGIN_PHONE_ERROR(false, 28009, "手机号码不正确"),
    LOGIN_MOBILE_ERROR(false, 28001, "账号不正确"),
    LOGIN_PASSWORD_ERROR(false, 28008, "密码不正确"),
    LOGIN_DISABLED_ERROR(false, 28002, "该用户已被禁用"),
    REGISTER_MOBLE_ERROR(false, 28003, "手机号已被注册"),
    LOGIN_AUTH(false, 28004, "需要登录"),
    LOGIN_ACL(false, 28005, "没有权限"),
    SMS_SEND_ERROR(false, 28006, "短信发送失败"),
    SMS_SEND_ERROR_BUSINESS_LIMIT_CONTROL(false, 28007, "短信发送过于频繁");


    private Boolean success;

    private Integer code;

    private String message;

    ResultCode(Boolean success, Integer code, String message) {
        this.success = success;
        this.code = code;
        this.message = message;
    }
}

R

package com.qq.first_project.common;

import lombok.Data;

import java.util.HashMap;
import java.util.Map;

/**
 *
 * @ClassName: R
 * @Description: 返回结果集
 * @author: Qiu
 */
@Data
public class R {

    /**
     * 是否成功
     */
    private Boolean success;

    /**
     * 返回码"
     */
    private Integer code;

    /**
     * 返回消息
     */
    private String message;

    /**
     * 返回数据
     */
    private Map<String, Object> data = new HashMap<String, Object>();

    public R(){}

    public static R ok(){
        R r = new R();
        r.setSuccess(ResultCode.SUCCESS.getSuccess());
        r.setCode(ResultCode.SUCCESS.getCode());
        r.setMessage(ResultCode.SUCCESS.getMessage());
        return r;
    }

    public static R error(){
        R r = new R();
        r.setSuccess(ResultCode.UNKNOWN_REASON.getSuccess());
        r.setCode(ResultCode.UNKNOWN_REASON.getCode());
        r.setMessage(ResultCode.UNKNOWN_REASON.getMessage());
        return r;
    }

    public static R setResult(ResultCode resultCode){
        R r = new R();
        r.setSuccess(resultCode.getSuccess());
        r.setCode(resultCode.getCode());
        r.setMessage(resultCode.getMessage());
        return r;
    }

    public R success(Boolean success){
        this.setSuccess(success);
        return this;
    }

    public R message(String message){
        this.setMessage(message);
        return this;
    }

    public R code(Integer code){
        this.setCode(code);
        return this;
    }

    public R data(String key, Object value){
        this.data.put(key, value);
        return this;
    }

    public R data(Map<String, Object> map){
        this.setData(map);
        return this;
    }
}

后续可能还会有更多工具类，配置等等，可根据项目情况再增加。