像商品价格，订单，结算都会涉及到一些金额的问题，为了避免精度丢失通常会做一些处理，常规的系统中金额一般精确到小数点后两位，也就是分；

这样数据库在设计的时候金额就直接存储整型数据类型，前端可以将金额X100以分为单位传给后端，后端进行一系列逻辑处理后要以元为单位返回前端直接展示，

这时候就可以定义一个简单的处理工具来转换：

public class MoneyConvert {

//分转换为元，返回string类型

public String centToDollarForString(T t){

if (t == null) {

return "0";

} else {

BigDecimal amount = getBigDecimal(t);

amount = amount.divide(new BigDecimal(100));

return amount.toString();

}

}

//分转换为元，返回double类型

public Double centToDollarForDouble(T t){

if (t == null) {

return 0D;

} else {

BigDecimal amount = getBigDecimal(t);

amount = amount.divide(new BigDecimal(100));

return amount.doubleValue();

}

}

private BigDecimal getBigDecimal(T t) {

BigDecimal amount;

if(t instanceof Integer){

amount = new BigDecimal(t.toString());

}

else if(t instanceof Long){

amount = new BigDecimal(t.toString());

}

else if(t instanceof String){

amount=new BigDecimal(t.toString());

}

else{

throw new RuntimeException(String.format("不支持的数据类型,%s",t.getClass()));

}

return amount;

}

}

//转换类

public class IntegerCentToStringDollar extends JsonSerializer {

@Override

public void serialize(Integer value, JsonGenerator gen, SerializerProvider serializers) throws IOException, JsonProcessingException {

gen.writeNumber(new MoneyConvert().centToDollarForString(value));

}

}

import com.blogs.common.utils.IntegerCentToStringDollar;

import com.fasterxml.jackson.databind.annotation.JsonSerialize;

//在需要处理的字段上加上注解@JsonSerialize(using = IntegerCentToStringDollar.class)

public class TestVo {

private Integer id;

@JsonSerialize(using = IntegerCentToStringDollar.class)

private Integer money;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public Integer getMoney() {

return money;

}

public void setMoney(Integer money) {

this.money = money;

}

}

@RestController

public class Demo {

@RequestMapping("/test")

public TestVo testMoneyConvert(){

TestVo vo=new TestVo();

vo.setId(1);

vo.setMoney(123);

return vo;

}

}

//结果展示：