Java -- 數據庫常量定義方式

1、常量描述註解 ConstName

package com.vim.common.consts;

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 )
public @interface ConstName {
    public String value() default "";
}

2、常量類

package com.vim.common.consts.bis;

import com.vim.common.consts.ConstName;

public interface ProductStateConsts {
    @ConstName("下架")
    public static byte PRODUCT_STATE_OFFSALE  =  0;
    @ConstName("上架")
    public static byte PRODUCT_STATE_ONSALE = 1;
}

3、讀取常量文本

package com.vim.common.utils;

import com.vim.common.consts.ConstName;
import java.lang.reflect.Field;

public class ConstUtils {

    public static String getBisConstName(Class<?> clazz,int code){
        Field fields[]=clazz.getDeclaredFields();
        for(Field f:fields){
            try {
                Integer k = new Integer(f.getInt(null));
                ConstName cn = f.getAnnotation(ConstName.class);
                if(null!=cn){
                    String value = cn.value();
                    if(k.intValue() == code) return value;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return "";
    }
}

4、常量類使用

package com.vim.modules.web.model;

import java.io.Serializable;

public class Product implements Serializable {
    
    /**
     * 狀態
     */
    private Byte state;

    public Byte getState() {
        return state;
    }

    public void setState(Byte state) {
        this.state = state;
    }
}