正确实施异步任务DbOperations的 [英] Proper implementation of DbOperations in Async Task

问题描述

在我的Andr​​oid应用程序，我有不同的实体，如用户自定义。我使用具有默认选择，插入，更新<单DbOperations类/ code>和删除功能。

In my android application, I have various "entities" such as user defined. I'm using a single DbOperations class that has the default Select, Insert, Update and Delete functionality.

这是异步任务被用作中介。它坐落在我的实体和DbOperations类之间异步执行的一切。下面是一个例子。

An async task is used as an intermediary. It sits in between my entities and DbOperations class and performs everything asynchronously. Here's an example.

异步CLASS - 用插入法code

private DbResponse InsertUser() {       
    ContentValues cntValues = GetCrmUserContentVal();
    long result = _dbConn.InsertRecord(cntValues, TABLE_NAME);
    DbResponse dbResponse = new DbResponse();
    if(result == -1)
    {
        dbResponse.setStatus(false);        
    }
    else {
        dbResponse.setStatus(true);
        dbResponse.setID(result);
    }
    return dbResponse;

}

CRM用户实体类 - 插入法

public void InsertintoDb()
    {
        new CRMUserDbOperations(this,this,DbOperationType.Insert,getCurrentContext()).execute();
    }

DbResponse - 返回类型的类是一个独立的类 -

DbResponse - Return type class is a seperate class -

private Boolean Status;
private String ErrorMessage;
private Cursor Data;
private long ID;
private DbOperationType dbOpType;

在 doBackground 异步任务的过程中，我有这个开关code -

In the doBackground process of the async task, I have this switch code -

switch (_DbOpType) { // Enum type.
            case Insert:
                dbResponse = InsertUser();
                break;
            case Select:
                dbResponse = SelectUser();
                break;
            case Update:
                dbResponse = UpdateUser();
                break;
            default:
                throw new InvalidParameterException(
                        _Context.getString(R.string.invalid_io));
        }

正如你可以看到这个异步任务code所有我可能要对实体执行各种操作。对于其他实体，我将具有相同的结构，以及...

As you can notice this asynchronous task has code for all the various operations I might have to perform on the entity. For other entities, I'll have the same structure as well...

现在我的问题是，我能在一个更好的方式这样做？

Now my question is, could I be doing this in a better manner?

推荐答案

是的，它可以以更好的方式来完成。让我给你的，我们是如何处理它在我们当前应用的例子。你只需要4 的AsyncTask S IN总插入，更新，删除和选择操作。让我给你举个例子。

Yes it can be done in a better way. Let me give you an example of how we are handling it in our current app. You just need 4 AsyncTasks in total for insert, update, delete and select operations. Let me give you an example.

您有一个接口，每一个实体将实现它：

You have an interface and every entity will implement it:

public interface DbOps {

    public int delete(String where);

    public void insert();

    public void update();

    public Cursor select();
}

注意：参数和返回值将是您选择适合您的需要，但也必须适合每一个实体类。我将使用删除（）方法为例。

NOTE: Arguments and return types will be of your choice that fits your need but must also fit for every entity class. I am going to use delete() method as an example.

现在，你只需要一个 DeleteTask活动所有entitites：

Now you need only one DeleteTask for all entitites:

private static class DeleteTask extends AsyncTask<String, Void, Integer> {
    private final DbOps mOps; 

    public RowDeleteTask(DbOps ops) {
        mOps = ops; 
    }

    @Override
    protected Integer doInBackground(String... wheres) {
        String where = wheres[0];
        int rowsDeleted = mOps.delete(where);
        return rowsDeleted;
    }
}

火这样的：

new DeleteTask(mUserEntity).execute("id = 4");
new DeleteTask(mMoviesEntity).execute("name = x-man");

和很明显，你将有类似这样的东西，如果我们采取 UserEntitiy 例如：

and obviously you will have something similar to this if we take UserEntitiy for example:

public UserEntity implements DbOps{

    @Override
    public int delete(String where){
       return _dbConn.delete(mTable, where, null);
    }
    .
    .
    .
}

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