double转json格式化添加自定义注解

aop拦截：
`
import com.fasterxml.jackson.databind.introspect.Annotated;
import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;
import com.xyzq.afa.customer.format.CustomDoubleSerialize;
import com.xyzq.afa.customer.format.DoubleFormatter;

public class DoubleFormatterAnnotationIntrospector extends JacksonAnnotationIntrospector {

private static final long serialVersionUID = 7368707128625539909L;

@Override
public Object findSerializer(Annotated annotated) {
    DoubleFormatter formatter = annotated.getAnnotation(DoubleFormatter.class);
    if (formatter != null) {
        return new CustomDoubleSerialize(formatter.pattern());
    }
    return super.findSerializer(annotated);
}

}

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;
import java.text.DecimalFormat;

/**

• 设置默认返回的小数类型(0.00)
  */
  public class CustomDoubleSerialize extends JsonSerializer {
  private DecimalFormat df;

  public CustomDoubleSerialize(String pattern) {
  this.df = new DecimalFormat(pattern);
  }

  @Override
  public void serialize(Double value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
  jgen.writeString(this.df.format(value));
  }
  }
  ``

自定义注解
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
/**

• 自定义double格式化注解
  */
  public @interface DoubleFormatter {
  String pattern() default "###,##0.00";
  }
  `