Question

我经常使用writeToRealm方法。我需要从不同的线程中使用它并切断样板代码。这项任务的更好方法是什么？

SELECT mp.PerTPay,bz.BizCode,bz.BizName,count(mp.PerTPay) PerCount, count(mp2.PerTPay) PerCount2 FROM tb_perbiz bz
LEFT JOIN ms_per mp ON BizCode=mp.PerBiz AND mp.PerTPay = 1
LEFT JOIN ms_per mp2 ON BizCode=mp2.PerBiz AND mp2.PerTPay = 2
GROUP BY bz.BizCode,mp.PerTPay
ORDER BY bz.BizCode,mp.PerTPay

}

我打算使用下面的构造（或类似的东西），但我无法创建正确的构造：

private boolean writeToRealm(String user, String id) {

        SubscriberObject subscriber = new SubscriberObject();

        if(mRealm.where(SubscriberObject.class)
                .equalTo(SubscriberObject.ID,id).findAll().isEmpty()
                &&mRealm.where(SubscriberObject.class)
               .equalTo(SubscriberObject.USERNAME,user).findAll().isEmpty()) {
            subscriber.setId(id);
            subscriber.setUsername(user);
            mRealm.beginTransaction();
            mRealm.insert(subscriber);
            mRealm.commitTransaction();
            return true;
        }
        return  false;

或者我可能需要为此任务创建一个带有looper的线程类？

如何更好地将此方法和类似方法集成到干净的架构中？

Answer 1

我认为你只是在寻找

private boolean writeToRealm(String user, String id) {
    try(Realm realm = Realm.getDefaultInstance()) {           
        if(realm.where(SubscriberObject.class).equalTo(SubscriberObject.ID,id).count() <= 0L 
              && realm.where(SubscriberObject.class).equalTo(SubscriberObject.USERNAME,user).count() <= 0L) {
            final SubscriberObject subscriber = new SubscriberObject();
            subscriber.setId(id);
            subscriber.setUsername(user);
            realm.executeTransaction(r -> r.insert(subscriber));
            return true;
        }
    }
    return false;
}

Answer 2

我认为这可能是一种更简单的解决方案：

public static Boolean writeToRealm(String user, String id) {
    Realm realm = Realm.getDefaultInstance();
    SubscriberObject subscriber = new SubscriberObject();
    if (realm.where(SubscriberObject.class).equalTo("ID", id).or().equalTo("USERNAME", user).findAll().isEmpty()){
        subscriber.setId(id);
        subscriber.setUsername(user);
        realm.beginTransaction();
        realm.insert(subscriber);
        realm.commitTransaction();
        realm.close();
        return true;
    }
    realm.close();
    return false;
}

如果你需要一些解释，请告诉我，我会实施它：）

PS：如果我误解了你的问题，请告诉我！

Answer 3

异步事务支持的工作方式与当前的executeTransaction相同，但不是在同一个线程上打开Realm，它将为您提供在不同线程上打开的后台Realm。如果您希望在事务完成或失败时收到通知，也可以注册回调。

    realm.executeTransactionAsync(new Realm.Transaction() {
    @Override
    public void execute(Realm realm) {
        Dog dog = realm.where(Dog.class).equalTo("age", 1).findFirst();
        dog.setName("Fido");
    }
}, new Realm.Transaction.OnSuccess() {
    @Override
    public void onSuccess() {
        Log.d("REALM", "All done updating.");
        Log.d("BG", t.getName());
    }
}, new Realm.Transaction.OnError() {
    @Override
    public void onError(Throwable error) {
        // transaction is automatically rolled-back, do any cleanup here
    }
});

Answer 4

首先，如果要异步执行事务，则不能拥有import org.apache.poi.ss.usermodel.*; import org.apache.poi.ss.usermodel.CellType.*; import org.apache.poi.xssf.usermodel.*; import java.io.FileInputStream; import java.util.List; import java.util.ArrayList; class ReadExcelRichTextCells { public static void main(String[] args) throws Exception { Workbook wb = WorkbookFactory.create(new FileInputStream("ExcelRichTextCells.xlsx")); Sheet sheet = wb.getSheetAt(0); for (Row row : sheet) { for (Cell cell : row) { switch (cell.getCellTypeEnum()) { case STRING: XSSFRichTextString richtextstring = (XSSFRichTextString)cell.getRichStringCellValue(); String textstring = richtextstring.getString(); List<String> textparts = new ArrayList<String>(); if (richtextstring.hasFormatting()) { for (int i = 0; i < richtextstring.numFormattingRuns(); i++) { if (richtextstring.getFontOfFormattingRun(i)==null || !richtextstring.getFontOfFormattingRun(i).getStrikeout()) { int indexofformattingrun = richtextstring.getIndexOfFormattingRun(i); String textpart = textstring.substring(indexofformattingrun, indexofformattingrun + richtextstring.getLengthOfFormattingRun(i)); String[] textpart_split = textpart.split("-"); for (int j = 0; j < textpart_split.length; j++){ String text = textpart_split[j].replace("\n", "").trim(); if (!"".equals(text)) textparts.add(text); } } } } else { textparts.add(textstring); } System.out.println(textparts); break; //... default: System.out.println("default cell"); //should never occur } } } wb.close(); } }返回类型。您必须将boolean传递结果返回给调用者，或者您必须选择其他方法，例如RxJava。

只是举个例子。

RxJava方式（因为这是最简单的方法）：

Interface

您在所需的线程/计划上订阅了返回的public static Flowable<Boolean> writeToRealm(final String user,final String id) { return Flowable.fromCallable( new Callable<Boolean>() { @Override public Boolean call() throws Exception { Realm realm = Realm.getDefaultInstance(); if(realm.where(SubscriberObject.class) .equalTo(SubscriberObject.ID,id).findAll().isEmpty() &&realm.where(SubscriberObject.class) .equalTo(SubscriberObject.USERNAME,user).findAll().isEmpty()) { SubscriberObject subscriber = new SubscriberObject(); subscriber.setId(id); subscriber.setUsername(user); realm.beginTransaction(); realm.insert(subscriber); realm.commitTransaction(); mRealm.close(); return true; } mRealm.close(); return false; } }); }，以便在该特定线程上执行事务。

使用来自不同线程的领域事务

4 个答案: