让我们获得一个简单的示例:
Class Foo{
private BigDecimal item1;
private BigDecimal item2;
private BigDecimal item3;
private BigDecimal item4;
private BigDecimal item5;
//setters and getters
public BigDecimal getTotal(){
BigDecimal total = BigDecimal.ZERO;
if(null != item1){
total =total .add(item1);
}
if(null != item2){
total =total .add(item2);
}
...
...
}
}
我在实体级别中总结。这是正确的方法吗?
任何人都可以给我更好的代码以获取总价值
使用 List<BigDecimal>
public BigDecimal getTotal(){
List<BigDecimal> values = Arrays.asList(item1, item2, item3, item4, item5)
BigDecimal total = BigDecimal.ZERO;
for (BigDecimal value : values) {
if(value != null) {
total = total.add(value);
}
}
return total;
}
您可以使用循环使代码简单:
import java.util.Arrays;
...
public BigDecimal getTotal(){
BigDecimal total = BigDecimal.ZERO;
for(BigDecimal bd: Arrays.asList(item1,item2,item3,item4,item5)){
if(null != bd){
total =total .add(bd);
}
}
}
如果您的数字固定数量很少,则如下:
total = total.add(item1 ==null ? BigDecimal.ZERO : item1).add(item2 ==null ? BigDecimal.ZERO : item2).add(item3 ==null ? BigDecimal.ZERO : item3);
如果项目为null,则添加0,否则该项目本身。如果您的项目数量可变,则需要在数组中迭代它们或类似的内容:
for (BigDecimal current : myBigDecimalArray){
total = total.add(current ==null ? BigDecimal.ZERO : current );
}
如果您不介意使用反射:
public static BigDecimal sum(Object instance, String... fields) {
BigDecimal total = BigDecimal.ZERO;
for (String field : fields) {
BigDecimal value = getProperty(instance, field);
if (value != null) {
total = total.add(value);
}
}
return total;
}
样本:
annex.setOrTot(ReflectionUtils.sum(annex, "orEstadoOrg", "orSs", "orCcaa", "orCorpLoc", "orResto"));
annex.setIdpTot(ReflectionUtils.sum(annex, "idpEstadoOrg", "idpSs", "idpCcaa", "idpCorpLoc", "idpResto"));
annex.setDrTot(ReflectionUtils.sum(annex, "drEstadoOrg", "drSs", "drCcaa", "drCorPloc", "drResto"));
annex.setIdcTot(ReflectionUtils.sum(annex, "idcEstadoOrg", "idcSS", "idcCcaa", "idcCorPloc", "idCresto"));
java 8 ,可以使用stream api
BigDecimal total = itemList.stream().reduce(BigDecimal.ZERO, BigDecimal::add);