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文章目录
    
    
     
     
      
      
       
       
       
       
       
      
     
    
    
   
   
实现数据类型转换
   
1 Converter接口
   
@FunctionalInterface
public interface Converter
    
      {
    /** 提供类型转换的逻辑 */
    @Nullable
    T convert(S source);
}
    
   
2 案例
   
之前通过InitBinder和DateTimeFormat注解实现过字符串转date，现在也可以通过Converter实现该功能
   
package study.wyy.springboot.anno.web.convert;
import org.springframework.core.convert.converter.Converter;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
 * @author by wyaoyao
 * @Description
 * @Date 2021/2/15 7:49 下午
 */
@Component
public class String2DateConverter implements Converter
    
      {
    @Override
    public Date convert(String source) {
        if (StringUtils.isEmpty(source)) {
            throw new NullPointerException("Source can not be null!");
        }
        try {
            DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
            return format.parse(source);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}
    
   
注册
   
package study.wyy.springboot.anno.web.advice;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.support.GenericConversionService;
import org.springframework.format.datetime.DateFormatter;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.InitBinder;
@ControllerAdvice
public class DataFormatAdvice {
    @Autowired
    private Converter
    
      stringToDateConverter;
    @InitBinder
    public void dateBinder(WebDataBinder dataBinder) {
        ConversionService conversionService = dataBinder.getConversionService();
        if (conversionService instanceof GenericConversionService) {
            GenericConversionService genericConversionService = (GenericConversionService) conversionService;
            genericConversionService.addConverter(stringToDateConverter);
        }
    }
}
    
   
   

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