项目中通常有些需求为需要将某个sObject的数据列表按照某种规则排序显示到前台页面上，但是list上面的sort远远满足不了复杂的功能，此种情况需要自定义比较两个object大小的方法，所以需要创建Compare相关的类实现Comparable接口。
需求：实现Goods__c列表排序，GoodsBrand__c为华为的按照价格升序排序，GoodsBrand__c为联想的按照价格降序排列。
public without sharing class ComparedGoods implements Comparable{
private Goods__c goods{get;set;}
private static final String GOODS_BRAND_HUAWEI = '华为';
private static final String GOODS_BRAND_LIANXIANG = '联想';
public ComparedGoods(Goods__c obj) {
goods = obj;
}
public Integer compareTo(Object objectToCompareTo) {
Goods__c comparedGoods = (Goods__c)objectToCompareTo;
Integer comparedResult = 0;
if(comparedGoods.GoodsBrand__c == GOODS_BRAND_HUAWEI) {
if(goods.GoodsPrice__c > comparedGoods.GoodsPrice__c) {
comparedResult = 1;
} else if(goods.GoodsPrice__c < comparedGoods.GoodsPrice__c) {
comparedResult = -1;
}
} else if(comparedGoods.GoodsBrand__c == GOODS_BRAND_LIANXIANG) {
if(goods.GoodsPrice__c > comparedGoods.GoodsPrice__c) {
comparedResult = -1;
} else if(goods.GoodsPrice__c == comparedGoods.GoodsPrice__c) {
comparedResult = 0;
}
else if(goods.GoodsPrice__c < comparedGoods.GoodsPrice__c) {
comparedResult = 1;
}
}
return comparedResult;
}
}
用法：
总结：针对object需要比较大小的时候，可以实现Comparable接口，在其compareTo方法中实现比较的逻辑即可。此篇有错误的地方欢迎指正，有问题欢迎留言。