How Springboot+AOP implements time parameter format conversion

Foreword

Scenario

The time parameters passed from the front end can be converted into whatever custom time format we want on the back end.

In different business scenarios, when connected with the front end, the basic time parameters of a control are in a fixed format. In order to prevent the front end from converting the format of the time parameters, we made an agreement with the front end and asked them to pass a fixed format to the back end. You can convert the format according to your needs.

Effect

① Convert from yyyy-MM-dd HH:mm:ss to yyyy-MM-dd using:

② To convert from yyyyMMddHHmmss to yyyy-MM-dd HH:mm:ss use:

③ No more examples, in fact, you can convert it however you want.

Actual combat

pom.xml (aop dependency, lombok dependency):

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjtools</artifactId>
            <version>1.9.5</version>
        </dependency>
        <dependency>
            <groupId>aopalliance</groupId>
            <artifactId>aopalliance</artifactId>
            <version>1.0</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.0</version>
        </dependency>
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>3.3.0</version>
        </dependency>

Core (custom annotation interceptor):

Custom Annotation 1

DateField.java

Purpose: Used to mark which field needs time format conversion, configure old format, new format (default value can be written) .

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
 
/**
 * @Author: JCccc
 * @Date: 2022-4-11 18:45
 * @Description:
 */
 
@Target({ElementType.METHOD, ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface DateField {
 
    String oldPattern() default DateUtil.YYYY_MM_DD_HH_MM_SS;
    
    //新格式可以写默认也可以不写，如果业务比较固定，那么新时间格式和旧时间格式都可以固定写好
    String newPattern() default "";
}

Custom Annotation 2

NeedDateFormatConvert.java

Purpose: Used to mark which interface requires AOP time format conversion.

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
 
/**
 * @Author: JCccc
 * @Date: 2022-4-11 18:44
 * @Description:
 */
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface NeedDateFormatConvert {
 
}

Interceptor

DateFormatAspect.java

Purpose: Core conversion implementation logic.

import com.jctest.dotestdemo.util.DateUtil;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
 
import java.lang.reflect.Field;
import java.util.Objects;
 
 
/**
 * @Author: JCccc
 * @Date: 2022-4-11 18:57
 * @Description:
 */
@Aspect
@Component
public class DateFormatAspect {
    private static Logger log = LoggerFactory.getLogger(DateFormatAspect.class);
 
    @Pointcut("@annotation(com.jctest.dotestdemo.aop.dateFormat.NeedDateFormatConvert)")
    public void pointCut() {
    }
 
    @Around("pointCut()")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        //转换
        dateFormat(joinPoint);
        return joinPoint.proceed();
    }
 
    public void dateFormat(ProceedingJoinPoint joinPoint) {
        Object[] objects = null;
        try {
            objects = joinPoint.getArgs();
            if (objects.length != 0) {
                for (int i = 0; i < objects.length; i++) {
                    //当前只支持判断对象类型参数
                    convertObject(objects[i]);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException("参数异常");
 
        }
    }
 
    /**
     * 转换对象里面的值
     *
     * @param obj
     * @throws IllegalAccessException
     */
    private void convertObject(Object obj) throws IllegalAccessException {
 
        if (Objects.isNull(obj)) {
            log.info("当前需要转换的object为null");
            return;
        }
        Field[] fields = obj.getClass().getDeclaredFields();
        for (Field field : fields) {
            boolean containFormatField = field.isAnnotationPresent(DateField.class);
            if (containFormatField) {
                //获取访问权
                field.setAccessible(true);
                DateField annotation = field.getAnnotation(DateField.class);
                String oldPattern = annotation.oldPattern();
                String newPattern = annotation.newPattern();
                Object dateValue = field.get(obj);
                if (Objects.nonNull(dateValue) && StringUtils.hasLength(oldPattern) && StringUtils.hasLength(newPattern)) {
                    String newDateValue = DateUtil.strFormatConvert(String.valueOf(dateValue), oldPattern, newPattern);
                    if (Objects.isNull(newDateValue)){
                        log.info("当前需要转换的日期数据转换失败 dateValue = {}",dateValue.toString());
                        throw new RuntimeException("参数转换异常");
                    }
                    field.set(obj, newDateValue);
                }
            }
        }
    }
    
}

Tool Class

DateUtil.java

Purpose: Time format conversion function, defining various time formats.

import lombok.extern.slf4j.Slf4j;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
 
/**
 * @Author: JCccc
 * @Date: 2022-4-1 14:48
 * @Description:
 */
@Slf4j
public class DateUtil {
 
    public static final String YYYY_MM_DD_HH_MM_SS = "yyyy-MM-dd HH:mm:ss";
    public static final String YYYY_MM_DD = "yyyy-MM-dd";
    public static final String YYYY_MM = "yyyy-MM";
    public static final String YYYY = "yyyy";
    public static final String MM = "MM";
    public static final String DD = "dd";
    public static final String YYYYMMDDHHMMSS = "yyyyMMddHHmmss";
    public static final String YYYYMMDD = "yyyyMMdd";
 
    /**
     * 指定日期格式转换
     *
     * @param dateStr
     * @param oldPattern
     * @return
     */
    public static String strFormatConvert(String dateStr, String oldPattern,String newPattern) {
        try {
            DateTimeFormatter oldFormatter = DateTimeFormatter.ofPattern(oldPattern);
            DateTimeFormatter newFormatter = DateTimeFormatter.ofPattern(newPattern);
            return LocalDateTime.parse(dateStr, oldFormatter).format(newFormatter);
        } catch (Exception e) {
            log.error("strToDate is Exception. e:", e);
            return null;
        }
    }
}

Use

UserQueryVO.java

import com.jctest.dotestdemo.aop.dateFormat.DateField;
import com.jctest.dotestdemo.util.DateUtil;
import lombok.Data;
 
import java.io.Serializable;
 
/**
 * @Author: JCccc
 * @Date: 2022-4-1 14:48
 * @Description:
 */
@Data
public class UserQueryVO implements Serializable {
    /**
     * 开始时间
     */
    @DateField(oldPattern =DateUtil.YYYY_MM_DD_HH_MM_SS, newPattern = DateUtil.YYYY_MM_DD)
    private String startDate;
    /**
     * 结束时间
     */
    @DateField(oldPattern =DateUtil.YYYY_MM_DD_HH_MM_SS,newPattern = DateUtil.YYYY_MM_DD)
    private String endDate;
}

Interface

import com.jctest.dotestdemo.aop.dateFormat.NeedDateFormatConvert;
import com.jctest.dotestdemo.vo.UserQueryVO;
import org.springframework.web.bind.annotation.*;
 
/**
 * @Author: JCccc
 * @Date: 2022-4-18 11:52
 * @Description:
 */
@RestController
public class UserController {
 
    @NeedDateFormatConvert
    @PostMapping("/test")
    public String test( @RequestBody UserQueryVO userQueryVO){
        System.out.println("时间格式转化完成：");
        System.out.println(userQueryVO.getStartDate());
        System.out.println(userQueryVO.getEndDate());
        return userQueryVO.toString();
    }
}

Call

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