MesosferQuery

java.lang.Object
- com.eyro.mesosfer.MesosferQuery<T>

public final class MesosferQuery<T extends com.eyro.mesosfer.CoreObject>
extends java.lang.Object

The MesosferQuery class defines a query that is used to fetch MesosferDatas. The most common use case is finding all objects that match a query through the findAsync(FindCallback) method, using a FindCallback. For example, this sample code fetches all objects of bucket "MyBucket". It calls a different function depending on whether the fetch succeeded or not.

 MesosferQuery<MesosferData> query = MesosferData.getQuery("MyBucket");
 query.findAsync(new FindCallback<MesosferData>() {
     public void done(List<MesosferData> objects, ParseException e) {
         if (e == null) {
             objectsWereRetrievedSuccessfully(objects);
         } else {
             objectRetrievalFailed();
         }
     }
 }

A MesosferQuery can also be used to count the number of objects that match the query without retrieving all of those objects. For example, this sample code counts the number of objects of the class "MyBucket".

 MesosferQuery<MesosferData> query = MesosferQuery.getQuery("MyBucket");
 query.countAsync(new CountCallback() {
     public void done(int count, ParseException e) {
         if (e == null) {
             objectsWereCounted(count);
         } else {
             objectCountFailed();
         }
     }
 }

Using the callback methods is usually preferred because the network operation will not block the calling thread.

Author:: Eyro Labs

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`MesosferQuery<T>`	`addAscendingOrder(java.lang.String key)` Also sorts the results in ascending order by the given key.
`MesosferQuery<T>`	`addDescendingOrder(java.lang.String key)` Also sorts the results in descending order by the given key.
`void`	`countAsync(CountCallback callback)` Counts the number of objects that match this query in a background thread.
`void`	`findAsync(FindCallback<T> callback)` Retrieves a list of `MesosferData`s or `MesosferUser`s that satisfy this query from the source in a background thread.
`void`	`getAsync(java.lang.String objectId, GetCallback<T> callback)` Constructs a `MesosferData` whose id is already known by fetching data from the source in a background thread.
`static <T extends com.eyro.mesosfer.CoreObject> MesosferQuery<T>`	`or(java.util.List<MesosferQuery<T>> queries)` Constructs a query that is the `or` of the given queries.
`MesosferQuery<T>`	`orderByAscending(java.lang.String key)` Sorts the results in ascending order by the given key.
`MesosferQuery<T>`	`orderByDescending(java.lang.String key)` Sorts the results in descending order by the given key.
`MesosferQuery<T>`	`setLimit(int newLimit)` Controls the maximum number of results that are returned.
`MesosferQuery<T>`	`setSkip(int newSkip)` Controls the number of results to skip before returning any results.
`MesosferQuery<T>`	`whereContains(java.lang.String key, java.lang.String substring)` Add a constraint for finding string values that contain a provided string.
`MesosferQuery<T>`	`whereDoesNotExist(java.lang.String key)` Add a constraint for finding objects that do not contain a given key.
`MesosferQuery<T>`	`whereEndsWith(java.lang.String key, java.lang.String suffix)` Add a constraint for finding string values that end with a provided string.
`MesosferQuery<T>`	`whereEqualTo(java.lang.String key, java.lang.Object value)` Add a constraint to the query that requires a particular key's value to be equal to the provided value.
`MesosferQuery<T>`	`whereExists(java.lang.String key)` Add a constraint for finding objects that contain the given key.
`MesosferQuery<T>`	`whereGreaterThan(java.lang.String key, java.lang.Object value)` Add a constraint to the query that requires a particular key's value to be greater than the provided value.
`MesosferQuery<T>`	`whereGreaterThanOrEqualTo(java.lang.String key, java.lang.Object value)` Add a constraint to the query that requires a particular key's value to be greater than or equal to the provided value.
`MesosferQuery<T>`	`whereLessThan(java.lang.String key, java.lang.Object value)` Add a constraint to the query that requires a particular key's value to be less than the provided value.
`MesosferQuery<T>`	`whereLessThanOrEqualTo(java.lang.String key, java.lang.Object value)` Add a constraint to the query that requires a particular key's value to be less than or equal to the provided value.
`MesosferQuery<T>`	`whereNotEqualTo(java.lang.String key, java.lang.Object value)` Add a constraint to the query that requires a particular key's value to be not equal to the provided value.
`MesosferQuery<T>`	`whereStartsWith(java.lang.String key, java.lang.String prefix)` Add a constraint for finding string values that start with a provided string.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - whereEqualTo
```
public MesosferQuery<T> whereEqualTo(java.lang.String key,
                                     java.lang.Object value)
```
    Add a constraint to the query that requires a particular key's value to be equal to the provided value.
    
    Parameters:
    
    key - The key to check.
    
    value - The value that the MesosferObject must contain.
    
    Returns:
    
    this, so you can chain this call.
  - whereLessThan
```
public MesosferQuery<T> whereLessThan(java.lang.String key,
                                      java.lang.Object value)
```
    Add a constraint to the query that requires a particular key's value to be less than the provided value.
    
    Parameters:
    
    key - The key to check.
    
    value - The value that provides an upper bound.
    
    Returns:
    
    this, so you can chain this call.
  - whereNotEqualTo
```
public MesosferQuery<T> whereNotEqualTo(java.lang.String key,
                                        java.lang.Object value)
```
    Add a constraint to the query that requires a particular key's value to be not equal to the provided value.
    
    Parameters:
    
    key - The key to check.
    
    value - The value that must not be equalled.
    
    Returns:
    
    this, so you can chain this call.
  - whereGreaterThan
```
public MesosferQuery<T> whereGreaterThan(java.lang.String key,
                                         java.lang.Object value)
```
    Add a constraint to the query that requires a particular key's value to be greater than the provided value.
    
    Parameters:
    
    key - The key to check.
    
    value - The value that provides an lower bound.
    
    Returns:
    
    this, so you can chain this call.
  - whereLessThanOrEqualTo
```
public MesosferQuery<T> whereLessThanOrEqualTo(java.lang.String key,
                                               java.lang.Object value)
```
    Add a constraint to the query that requires a particular key's value to be less than or equal to the provided value.
    
    Parameters:
    
    key - The key to check.
    
    value - The value that provides an upper bound.
    
    Returns:
    
    this, so you can chain this call.
  - whereGreaterThanOrEqualTo
```
public MesosferQuery<T> whereGreaterThanOrEqualTo(java.lang.String key,
                                                  java.lang.Object value)
```
    Add a constraint to the query that requires a particular key's value to be greater than or equal to the provided value.
    
    Parameters:
    
    key - The key to check.
    
    value - The value that provides an lower bound.
    
    Returns:
    
    this, so you can chain this call.
  - whereContains
```
public MesosferQuery<T> whereContains(java.lang.String key,
                                      java.lang.String substring)
```
    Add a constraint for finding string values that contain a provided string.
    This will be slow for large datasets.
    
    Parameters:
    
    key - The key that the string to match is stored in.
    
    substring - The substring that the value must contain.
    
    Returns:
    
    this, so you can chain this call.
  - whereStartsWith
```
public MesosferQuery<T> whereStartsWith(java.lang.String key,
                                        java.lang.String prefix)
```
    Add a constraint for finding string values that start with a provided string.
    This query will use the backend index, so it will be fast even for large datasets.
    
    Parameters:
    
    key - The key that the string to match is stored in.
    
    prefix - The substring that the value must start with.
    
    Returns:
    
    this, so you can chain this call.
  - whereEndsWith
```
public MesosferQuery<T> whereEndsWith(java.lang.String key,
                                      java.lang.String suffix)
```
    Add a constraint for finding string values that end with a provided string.
    This will be slow for large datasets.
    
    Parameters:
    
    key - The key that the string to match is stored in.
    
    suffix - The substring that the value must end with.
    
    Returns:
    
    this, so you can chain this call.
  - whereExists
```
public MesosferQuery<T> whereExists(java.lang.String key)
```
    Add a constraint for finding objects that contain the given key.
    
    Parameters:
    
    key - The key that should exist.
    
    Returns:
    
    this, so you can chain this call.
  - whereDoesNotExist
```
public MesosferQuery<T> whereDoesNotExist(java.lang.String key)
```
    Add a constraint for finding objects that do not contain a given key.
    
    Parameters:
    
    key - The key that should not exist
    
    Returns:
    
    this, so you can chain this call.
  - orderByAscending
```
public MesosferQuery<T> orderByAscending(java.lang.String key)
```
    Sorts the results in ascending order by the given key.
    
    Parameters:
    
    key - The key to order by.
    
    Returns:
    
    this, so you can chain this call.
  - addAscendingOrder
```
public MesosferQuery<T> addAscendingOrder(java.lang.String key)
```
    Also sorts the results in ascending order by the given key.
    The previous sort keys have precedence over this key.
    
    Parameters:
    
    key - The key to order by
    
    Returns:
    
    this, so you can chain this call.
  - orderByDescending
```
public MesosferQuery<T> orderByDescending(java.lang.String key)
```
    Sorts the results in descending order by the given key.
    
    Parameters:
    
    key - The key to order by.
    
    Returns:
    
    this, so you can chain this call.
  - addDescendingOrder
```
public MesosferQuery<T> addDescendingOrder(java.lang.String key)
```
    Also sorts the results in descending order by the given key.
    The previous sort keys have precedence over this key.
    
    Parameters:
    
    key - The key to order by
    
    Returns:
    
    this, so you can chain this call.
  - setLimit
```
public MesosferQuery<T> setLimit(int newLimit)
```
    Controls the maximum number of results that are returned.
    Setting a negative limit denotes retrieval without a limit. The default limit is 100, with a maximum of 1000 results being returned at a time.
    
    Parameters:
    
    newLimit - The new limit.
    
    Returns:
    
    this, so you can chain this call.
  - setSkip
```
public MesosferQuery<T> setSkip(int newSkip)
```
    Controls the number of results to skip before returning any results.
    This is useful for pagination. Default is to skip zero results.
    
    Parameters:
    
    newSkip - The new skip
    
    Returns:
    
    this, so you can chain this call.
  - or
```
public static <T extends com.eyro.mesosfer.CoreObject> MesosferQuery<T> or(java.util.List<MesosferQuery<T>> queries)
```
    Constructs a query that is the or of the given queries.
    
    Parameters:
    
    queries - The list of MesosferQuerys to 'or' together
    
    Returns:
    
    A MesosferQuery that is the 'or' of the passed in queries
  - getAsync
```
public void getAsync(java.lang.String objectId,
                     GetCallback<T> callback)
```
    Constructs a MesosferData whose id is already known by fetching data from the source in a background thread. This does not use caching.
    This is preferable to using the MesosferData.createWithObjectId(String), unless your code is already running in a background thread.
    
    Parameters:
    
    objectId - Object id of the MesosferData to fetch.
    
    callback - callback.done(object, e) will be called when the fetch completes.
  - countAsync
```
public void countAsync(CountCallback callback)
```
    Counts the number of objects that match this query in a background thread. This does not use caching.
    
    Parameters:
    
    callback - callback.done(count, e) will be called when the count completes.
  - findAsync
```
public void findAsync(FindCallback<T> callback)
```
    Retrieves a list of MesosferDatas or MesosferUsers that satisfy this query from the source in a background thread.
    
    Parameters:
    
    callback - callback.done(objectList, e) is called when the find completes.

Class MesosferQuery<T extends com.eyro.mesosfer.CoreObject>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

whereEqualTo

whereLessThan

whereNotEqualTo

whereGreaterThan

whereLessThanOrEqualTo

whereGreaterThanOrEqualTo

whereContains

whereStartsWith

whereEndsWith

whereExists

whereDoesNotExist

orderByAscending

addAscendingOrder

orderByDescending

addDescendingOrder

setLimit

setSkip

or

getAsync

countAsync

findAsync