将自定义类保存到数据库中，自定义序列化规则 [英] Persist custom class into database, custom serialization rules

问题描述

我有这个课程

pre $ public class Money {
private BigDecimal amount;
私人字符串货币;
}


我想创建一个自定义的序列化器或类似的方法来告诉hibernate以这种方式将 Money 类持久保存为字符串： 23.00 EUR

基本上，序列化将是金额用2位小数进行舍入+空格+ 货币，反序列化将遵循相反的逻辑。

实现起来应该不难，但我找不到提示。
任何想法如何做到这一点？

解决方案

准备去：AttributeConverter

  import javax.persistence.AttributeConverter; 
 
 
 @Converter（autoApply = true）
公共类MoneyAttributeConverter实现了AttributeConverter< Money，String> {
 
 @Override 
 public String convertToDatabaseColumn（Money in）{
 return ... convert here; 
} 
 
 @Override 
 public Money convertToEntityAttribute（String in）{
 return ... and here; 
 
 
 $ / code> 

希望helpul：）



编辑。关于边距的说明，序列化与持久性是相似的，但不一样。 Google in the net @Transient 注释与瞬态关键字之间的差异


I have this class

public class Money {
   private BigDecimal amount;
   private String currency;
}

I would like, by creating a custom serializator or similar ways, to tell hibernate to persist the Money class as String in this way: 23.00 EUR

Basically the serialization will be amount rounded with 2 decimals + space + currency, and the deserialization will follow the inverse logic.

It shouldn't be difficult to implement, but I couldn't find hints. Any ideas how to do that?

解决方案

Ready to go: AttributeConverter

import javax.persistence.AttributeConverter;


@Converter(autoApply = true)
public class MoneyAttributeConverter implements AttributeConverter<Money, String> {

    @Override
    public String convertToDatabaseColumn(Money in) {
        return ... convert here;
    }

    @Override
    public Money  convertToEntityAttribute(String in) {
        return ... and here;
    }
}

Hope helpul :)

EDIT. Note on the margin, serialisation is 'similar' to persistence, but not the same. Google in the net "differences between @Transient annotation and transient keyword"

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