推荐使用JDK7中新引入的Objects工具类来进行对象的equals比较，直接a.equals(b)，有空指针异常的风险

public final class Objects {/**
     * Returns {@code true} if the arguments are equal to each other
     * and {@code false} otherwise.
     * Consequently, if both arguments are {@code null}, {@code true}
     * is returned and if exactly one argument is {@code null}, {@code
     * false} is returned.  Otherwise, equality is determined by using
     * the {@link Object#equals equals} method of the first
     * argument.
     *
     * @param a an object
     * @param b an object to be compared with {@code a} for equality
     * @return {@code true} if the arguments are equal to each other
     * and {@code false} otherwise
     * @see Object#equals(Object)
     */
    public static boolean equals(Object a, Object b) {
        return (a == b) || (a != null && a.equals(b));
    }
}

示例：如下所示，如果需要进行equals的两个都是字符串变量，那么就应该使用Objects.equals(Object a,Object b) 方法。

for(int k = 0; k < listSize; k ++){
            Map<String,Object> item = list.get(k);
            String curInStoreNoteNo = item.get("inStoreNoteNo").toString();
            String curDeliveryEntNo = item.get("deliveryEntNo").toString();
            if(k > 0){
                Map<String,Object> map = list.get(k - 1);
                String inStoreNoteNo = map.get("inStoreNoteNo").toString();
                String deliveryEntNo = map.get("deliveryEntNo").toString();
                if(curInStoreNoteNo.equals(inStoreNoteNo) && curDeliveryEntNo.equals(deliveryEntNo)){
                    if(k == listSize - 1){
                        margeRowList.add(k);
                    }
                }else{
                    margeRowList.add(k-1);
                }
            }
　　　　　　  ...
        }

修改如下：

for(int k = 0; k < listSize; k ++){
            Map<String,Object> item = list.get(k);
            String curInStoreNoteNo = item.get("inStoreNoteNo").toString();
            String curDeliveryEntNo = item.get("deliveryEntNo").toString();
            if(k > 0){
                Map<String,Object> map = list.get(k - 1);
                String inStoreNoteNo = map.get("inStoreNoteNo").toString();
                String deliveryEntNo = map.get("deliveryEntNo").toString();
                if(Objects.equals(curInStoreNoteNo,inStoreNoteNo) && Objects.equals(curDeliveryEntNo,deliveryEntNo)){
                    if(k == listSize - 1){ 
                        margeRowList.add(k);
                    }
                }else{ 
                    margeRowList.add(k-1);
                }
            }
　　　　　　　....
        }