Package io.jsondb.io

Class JsonWriter

java.lang.Object

io.jsondb.io.JsonWriter

public class JsonWriter
extends java.lang.Object

A special File Writer to write to the .json DB files that ensures proper character encoding is used and the necessary File Locks are created.

Constructor Summary

Constructors

Constructor	Description
JsonWriter(JsonDBConfig dbConfig, CollectionMetaData cmd, java.lang.String collectionName, java.io.File collectionFile)

Method Summary

Modifier and Type	Method	Description
<T> boolean	appendToJsonFile(java.util.Collection<T> collection, java.lang.Object objectToSave)	A utility method that appends the provided object to the end of collection file in a atomic way
<T> boolean	appendToJsonFile(java.util.Collection<T> collection, java.util.Collection<? extends T> batchToSave)	A utility method that appends the provided collection of objects to the end of collection file in a atomic way
<T> boolean	removeFromJsonFile(java.util.Map<java.lang.Object,T> collection, java.lang.Object id)	A utility method that substracts the provided Ids and writes rest of the collection to file in a atomic way
<T> boolean	removeFromJsonFile(java.util.Map<java.lang.Object,T> collection, java.util.Set<java.lang.Object> removeIds)	A utility method that subtracts the provided Ids and writes rest of the collection to file in a atomic way
<T> boolean	renameKeyInJsonFile(java.util.Collection<T> collection, boolean ignoreReadonly, java.lang.String oldKey, java.lang.String newKey)	A utility method renames a particular key for the entire contents of .json in a atomic way
<T> boolean	reWriteJsonFile(java.util.Collection<T> collection, boolean ignoreReadonly)	A utility method that completely replaces the contents of .json with the provided collection in a atomic way
<T> boolean	updateInJsonFile(java.util.Map<java.lang.Object,T> collection, java.lang.Object id, T objectToSave)	A utility method that updates the provided collection of objects into the existing collection file in a atomic way
<T> boolean	updateInJsonFile(java.util.Map<java.lang.Object,T> collection, java.util.Map<java.lang.Object,T> modifiedObjects)	A utility method that updates the provided collection of objects into the existing collection file in a atomic way

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JsonWriter

public JsonWriter(JsonDBConfig dbConfig,
                  CollectionMetaData cmd,
                  java.lang.String collectionName,
                  java.io.File collectionFile)
           throws java.io.IOException

Throws:

java.io.IOException

Method Detail

appendToJsonFile

public <T> boolean appendToJsonFile(java.util.Collection<T> collection,
                                    java.lang.Object objectToSave)

A utility method that appends the provided object to the end of collection file in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

objectToSave - new Object that is being inserted or updated.

Returns:

true if success

appendToJsonFile

public <T> boolean appendToJsonFile(java.util.Collection<T> collection,
                                    java.util.Collection<? extends T> batchToSave)

A utility method that appends the provided collection of objects to the end of collection file in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

batchToSave - collection of objects to append.

Returns:

true if success

removeFromJsonFile

public <T> boolean removeFromJsonFile(java.util.Map<java.lang.Object,T> collection,
                                      java.lang.Object id)

A utility method that substracts the provided Ids and writes rest of the collection to file in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

id - id of objects to be removed.

Returns:

true if success

removeFromJsonFile

public <T> boolean removeFromJsonFile(java.util.Map<java.lang.Object,T> collection,
                                      java.util.Set<java.lang.Object> removeIds)

A utility method that subtracts the provided Ids and writes rest of the collection to file in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

removeIds - ids of objects to be removed.

Returns:

true if success

updateInJsonFile

public <T> boolean updateInJsonFile(java.util.Map<java.lang.Object,T> collection,
                                    java.lang.Object id,
                                    T objectToSave)

A utility method that updates the provided collection of objects into the existing collection file in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

id - the id of object to save

objectToSave - the actual object to save.

Returns:

true if success

updateInJsonFile

public <T> boolean updateInJsonFile(java.util.Map<java.lang.Object,T> collection,
                                    java.util.Map<java.lang.Object,T> modifiedObjects)

A utility method that updates the provided collection of objects into the existing collection file in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

modifiedObjects - objects to update.

Returns:

true if success

reWriteJsonFile

public <T> boolean reWriteJsonFile(java.util.Collection<T> collection,
                                   boolean ignoreReadonly)

A utility method that completely replaces the contents of .json with the provided collection in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

ignoreReadonly - force rewrite even if the collection is marked readonly this is necessary for schemaupdate.

Returns:

true if success

renameKeyInJsonFile

public <T> boolean renameKeyInJsonFile(java.util.Collection<T> collection,
                                       boolean ignoreReadonly,
                                       java.lang.String oldKey,
                                       java.lang.String newKey)

A utility method renames a particular key for the entire contents of .json in a atomic way

Type Parameters:

T - Type annotated with Document annotation and member of the baseScanPackage

Parameters:

collection - existing collection

ignoreReadonly - force rewrite even if the collection is marked readonly this is necessary for schemaupdate.

oldKey - String representing the old key/field

newKey - String representing the new key/field

Returns:

true if success