领域 - 如果属性等于则不更新

Question

我正在使用适用于 Android 的领域。我有以下代码并且它可以工作，但我想知道这是否是更新对象的最佳方式以及它是否会导致任何性能问题。

目前，如果状态设置为处理中，我不想更新现有对象。

List<WorkOrderObject> woList = new ArrayList<>();
            for (int i = 0; i < openWorkOrders.size(); i++) {
                if (!visnetawrap.isUserLoggedIn) {
                    return;
                }
                WorkOrderObject wo = visnetawrap.gsonClient.fromJson(openWorkOrders.get(i).toString(), WorkOrderObject.class);

                WorkOrderObject currWO = realmThread.where(WorkOrderObject.class).equalTo("id", wo.getOrderRawId()).findFirst();
                if (currWO != null) {
                    if (currWO.getOrderStatus().equals("Processing")) {
                        continue;
                    }
                }

                issueDateTime = AppUtils.formatTimestampToDateTime(wo.getOrderIssueDate());
                issueDateString = issueDateTime.toLocalDateTime().toString("MM/dd/yyyy", Locale.US);
                dueDateTime = AppUtils.formatTimestampToDateTime(wo.getOrderDueDate());
                dueDateString = dueDateTime.toLocalDateTime().toString("MM/dd/yyyy", Locale.US);

                if (!issueDateString.equals("") && !issueDateString.equals("00/00/0000") && issueDateTime.getYear() >= now.getYear() && !dueDateString.equals("") && !dueDateString.equals("00/00/0000") && dueDateTime.getYear() >= now.getYear()) {
                    //Log.d("dueDate", dueDateString);
                    woList.add(wo);
                }
            }
            realmThread.beginTransaction();
            realmThread.copyToRealmOrUpdate(woList);
            realmThread.commitTransaction();

Answer 1

我认为基本上是一样的。
由于您担心性能，这里有一些可以改进的方法。

private static String PROCESSING = "Processing";
private static String DATE_FORMAT = "MM/dd/yyyy";
private static String EMPTY_DATE = "00/00/0000";

public void betterMethod() {
    List<WorkOrderObject> woList = new ArrayList<>(openWorkOrders.size());

    //I think this code doesnot need to be inside loop.
    if (!visnetawrap.isUserLoggedIn) {
        return;
    }
    for (int i = 0, j = openWorkOrders.size(); i < j; i++) {
        //Since you are using gson there are ways to convert JsonArray to list directly which is a better way than this
        WorkOrderObject wo = visnetawrap.gsonClient.fromJson(openWorkOrders.get(i).toString(), WorkOrderObject.class);

        WorkOrderObject currWO = realmThread.where(WorkOrderObject.class).equalTo("id", wo.getOrderRawId()).findFirst();

        if (currWO != null && currWO.getOrderStatus().equals(PROCESSING)) { //Its cleanar way
            continue;
        }

        issueDateTime = AppUtils.formatTimestampToDateTime(wo.getOrderIssueDate());
        issueDateString = issueDateTime.toLocalDateTime().toString(DATE_FORMAT, Locale.US);
        dueDateTime = AppUtils.formatTimestampToDateTime(wo.getOrderDueDate());
        dueDateString = dueDateTime.toLocalDateTime().toString(DATE_FORMAT, Locale.US);

        //I assume you have stripped out code where it needs string
        //You can use TextUtils.isEmpty() or issueDateString.isEmpty() , 
        // issueDateString.equals("") does is creates new String which is empty and compares issueDateString with it while above methods just check the 
        //length of string
        if (!TextUtils.isEmpty(issueDateString) && !issueDateString.equals(EMPTY_DATE) && issueDateTime.getYear() >= now.getYear() && !TextUtils.isEmpty(dueDateString) && !dueDateString.equals(EMPTY_DATE) && dueDateTime.getYear() >= now.getYear()) {
            //Log.d("dueDate", dueDateString);
            woList.add(wo);
        }
    }
    if (!woList.isEmpty()) {
        realmThread.beginTransaction();
        realmThread.copyToRealmOrUpdate(woList);
        realmThread.commitTransaction();
    }
}

1. For 循环可能非常大，因此像currWO.getOrderStatus().equals("Processing") 这样的条件语句将创建一个新字符串并进行比较。最好在之前初始化字符串，如上传递。

2. Converting JsonArray to List

3. 为什么要实例化 new ArrayList<>(openWorkOrders.size()) 之类的数组并使用带有 for (int i = 0, j = openWorkOrders.size(); i < j; i++) {} 之类的列表的 for 循环
   Streamlining Android Apps: Eliminating Code Overhead by Jake Wharton