org.litepal.crud

类 DeleteHandler

java.lang.Object

org.litepal.LitePalBase

org.litepal.crud.DeleteHandler

public class DeleteHandler
extends LitePalBase

This is a component under LitePalSupport. It deals with the deleting stuff as primary task. If deletes a saved model or delete a record with id, the cascade delete function would work. But considering efficiency, if deletes with deleteAll method, the referenced data in other tables will not be affected. Developers should remove those referenced data by their own.

从以下版本开始:

1.1

字段概要

字段

限定符和类型	字段和说明
static java.lang.String	TAG

构造器概要

构造器

构造器和说明
DeleteHandler(android.database.sqlite.SQLiteDatabase db) Initialize DataHandler.mDatabase for operating database.

方法概要

限定符和类型	方法和说明
protected void	analyzeAssociatedModels(LitePalSupport baseObj, java.util.Collection<AssociationsInfo> associationInfos) Find all the associated models of currently model.
protected java.lang.Object	createInstanceFromClass(java.lang.Class<?> modelClass) Creates an instance from the passed in class.
protected java.lang.Object	decryptValue(java.lang.String algorithm, java.lang.Object fieldValue) Decrypt the field value with targeted algorithm.
protected java.lang.Object	encryptValue(java.lang.String algorithm, java.lang.Object fieldValue) Encrypt the field value with targeted algorithm.
protected java.lang.reflect.Constructor<?>	findBestSuitConstructor(java.lang.Class<?> modelClass) Finds the best suit constructor for creating an instance of a class.
protected LitePalSupport	getAssociatedModel(LitePalSupport baseObj, AssociationsInfo associationInfo) Get the associated model.
protected java.util.Collection<LitePalSupport>	getAssociatedModels(LitePalSupport baseObj, AssociationsInfo associationInfo) Get the associated models collection.
protected java.lang.Object[]	getConstructorParams(java.lang.Class<?> modelClass, java.lang.reflect.Constructor<?> constructor) Depends on the passed in constructor, creating a parameters array with initialized values for the constructor.
protected LitePalSupport	getEmptyModel(LitePalSupport baseObj) Create an empty instance of baseObj if it hasn't created one yet.
protected java.lang.Object	getFieldValue(LitePalSupport dataSupport, java.lang.reflect.Field field) Get the field value for model.
protected java.util.List<AssociationsInfo>	getForeignKeyAssociations(java.lang.String className, boolean isEager) Get the foreign key associations of the specified class.
protected java.lang.String	getIntermediateTableName(LitePalSupport baseObj, java.lang.String associatedTableName) Get the name of intermediate join table.
protected java.lang.Class<?>[]	getParameterTypes(java.lang.reflect.Field field, java.lang.Object fieldValue, java.lang.Object[] parameters) Get the types of parameters for ContentValues.put(java.lang.String, java.lang.String).
protected java.lang.String	getTableName(java.lang.Class<?> modelClass) Get the simple name of modelClass.
protected java.lang.String[]	getWhereArgs(java.lang.String... conditions) Get the WHERE arguments to fill into where clause when updating or deleting multiple rows.
protected java.lang.String	getWhereClause(java.lang.String... conditions) Get the WHERE clause to apply when updating or deleting multiple rows.
protected java.lang.String	getWhereOfIdsWithOr(java.util.Collection<java.lang.Long> ids) Get the where clause by the passed in id collection to apply multiple rows.
protected java.lang.String	getWhereOfIdsWithOr(long... ids) Get the where clause by the passed in id array to apply multiple rows.
protected void	giveBaseObjIdValue(LitePalSupport baseObj, long id) Assign the generated id value to LitePalSupport.baseObjId.
protected boolean	isAffectAllLines(java.lang.Object... conditions) Check the passing conditions represent to affect all lines or not.
protected java.lang.String	makeGetterMethodName(java.lang.reflect.Field field) Generate the getter method name by field, following the Android Studio rule.
protected java.lang.String	makeSetterMethodName(java.lang.reflect.Field field) Generate the setter method name by field, following the Android Studio rule.
protected <T> T	mathQuery(java.lang.String tableName, java.lang.String[] columns, java.lang.String[] conditions, java.lang.Class<T> type) Handles the math query of the given table.
int	onDelete(java.lang.Class<?> modelClass, long id) The open interface for other classes in CRUD package to delete.
int	onDeleteAll(java.lang.Class<?> modelClass, java.lang.String... conditions)
int	onDeleteAll(java.lang.String tableName, java.lang.String... conditions) The open interface for other classes in CRUD package to delete multiple rows.
protected void	putContentValuesForSave(LitePalSupport baseObj, java.lang.reflect.Field field, android.content.ContentValues values) This method deals with the putting values job into ContentValues.
protected void	putContentValuesForUpdate(LitePalSupport baseObj, java.lang.reflect.Field field, android.content.ContentValues values) putContentValuesForUpdate operation is almost same with putContentValuesForSave, except allowing put null fieldValue into database, which is made for LitePalSupport.setToDefault(java.lang.String) function.
protected void	putFieldsValue(LitePalSupport baseObj, java.util.List<java.lang.reflect.Field> supportedFields, android.content.ContentValues values) Iterate all the fields passed in.
protected <T> java.util.List<T>	query(java.lang.Class<T> modelClass, java.lang.String[] columns, java.lang.String selection, java.lang.String[] selectionArgs, java.lang.String groupBy, java.lang.String having, java.lang.String orderBy, java.lang.String limit, java.util.List<AssociationsInfo> foreignKeyAssociations) Query the table of the given model, returning a model list over the result set.
protected void	setFieldValue(LitePalSupport dataSupport, java.lang.reflect.Field field, java.lang.Object parameter) Set the field value for model.
protected void	setGenericValueToModel(LitePalSupport baseObj, java.util.List<java.lang.reflect.Field> supportedGenericFields, java.util.Map<java.lang.reflect.Field,GenericModel> genericModelMap) Get generic value from generic tables, then set the value into the baseObj.
protected void	setValueToModel(java.lang.Object modelInstance, java.util.List<java.lang.reflect.Field> supportedFields, java.util.List<AssociationsInfo> foreignKeyAssociations, android.database.Cursor cursor, android.util.SparseArray<org.litepal.crud.DataHandler.QueryInfoCache> sparseArray) Get value from database by cursor, then set the value into modelInstance.
protected boolean	shouldGetOrSet(LitePalSupport dataSupport, java.lang.reflect.Field field) When executing getFieldValue(LitePalSupport, Field) or setFieldValue(LitePalSupport, Field, Object), the dataSupport and field passed in should be protected from null value.

从类继承的方法 org.litepal.LitePalBase

getAssociationInfo, getAssociations, getColumnType, getForeignKeyColumnName, getGenericModels, getGenericTypeClass, getGenericTypeName, getSupportedFields, getSupportedGenericFields, getTableModel, isCollection, isIdColumn, isList, isPrivate, isSet

从类继承的方法 java.lang.Object

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

字段详细资料

TAG

public static final java.lang.String TAG

另请参阅:

常量字段值

构造器详细资料

DeleteHandler

public DeleteHandler(android.database.sqlite.SQLiteDatabase db)

Initialize DataHandler.mDatabase for operating database. Do not allow to create instance of DeleteHandler out of CRUD package.

参数:

db - The instance of SQLiteDatabase.

方法详细资料

onDelete

public int onDelete(java.lang.Class<?> modelClass,
                    long id)

The open interface for other classes in CRUD package to delete. Using modelClass to decide which table to delete from, and id to decide a specific row. This method can action cascade delete. When the record is deleted from database, all the referenced data such as foreign key value will be removed too.

参数:

modelClass - Which table to delete from.

id - Which record to delete.

返回:

The number of rows affected. Including cascade delete rows.

onDeleteAll

public int onDeleteAll(java.lang.String tableName,
                       java.lang.String... conditions)

The open interface for other classes in CRUD package to delete multiple rows. Using tableName to decide which table to delete from, and conditions representing the WHERE part of an SQL statement.

参数:

tableName - Which table to delete from.

conditions - A string array representing the WHERE part of an SQL statement.

返回:

The number of rows affected.

onDeleteAll

public int onDeleteAll(java.lang.Class<?> modelClass,
                       java.lang.String... conditions)

query

protected <T> java.util.List<T> query(java.lang.Class<T> modelClass,
                                      java.lang.String[] columns,
                                      java.lang.String selection,
                                      java.lang.String[] selectionArgs,
                                      java.lang.String groupBy,
                                      java.lang.String having,
                                      java.lang.String orderBy,
                                      java.lang.String limit,
                                      java.util.List<AssociationsInfo> foreignKeyAssociations)

Query the table of the given model, returning a model list over the result set.

参数:

modelClass - The model to compile the query against.

columns - A list of which columns to return. Passing null will return all columns, which is discouraged to prevent reading data from storage that isn't going to be used.

selection - A filter declaring which rows to return, formatted as an SQL WHERE clause (excluding the WHERE itself). Passing null will return all rows for the given table.

selectionArgs - You may include ?s in selection, which will be replaced by the values from selectionArgs, in order that they appear in the selection. The values will be bound as Strings.

groupBy - A filter declaring how to group rows, formatted as an SQL GROUP BY clause (excluding the GROUP BY itself). Passing null will cause the rows to not be grouped.

having - A filter declare which row groups to include in the cursor, if row grouping is being used, formatted as an SQL HAVING clause (excluding the HAVING itself). Passing null will cause all row groups to be included, and is required when row grouping is not being used.

orderBy - How to order the rows, formatted as an SQL ORDER BY clause (excluding the ORDER BY itself). Passing null will use the default sort order, which may be unordered.

limit - Limits the number of rows returned by the query, formatted as LIMIT clause. Passing null denotes no LIMIT clause.

foreignKeyAssociations - Associated classes which have foreign keys in the current model's table.

返回:

A model list. The list may be empty.

mathQuery

protected <T> T mathQuery(java.lang.String tableName,
                          java.lang.String[] columns,
                          java.lang.String[] conditions,
                          java.lang.Class<T> type)

Handles the math query of the given table.

参数:

tableName - Which table to query from.

columns - A list of which columns to return. Passing null will return all columns, which is discouraged to prevent reading data from storage that isn't going to be used.

conditions - A filter declaring which rows to return, formatted as an SQL WHERE clause. Passing null will return all rows.

type - The type of the based on column.

返回:

The result calculating by SQL.

giveBaseObjIdValue

protected void giveBaseObjIdValue(LitePalSupport baseObj,
                                  long id)
                           throws java.lang.SecurityException,
                                  java.lang.NoSuchFieldException,
                                  java.lang.IllegalArgumentException,
                                  java.lang.IllegalAccessException

Assign the generated id value to LitePalSupport.baseObjId. This value will be used as identify of this model for system use.

参数:

baseObj - The class of base object.

id - The value of id.

抛出:

java.lang.SecurityException

java.lang.NoSuchFieldException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

putFieldsValue

protected void putFieldsValue(LitePalSupport baseObj,
                              java.util.List<java.lang.reflect.Field> supportedFields,
                              android.content.ContentValues values)
                       throws java.lang.SecurityException,
                              java.lang.IllegalArgumentException,
                              java.lang.NoSuchMethodException,
                              java.lang.IllegalAccessException,
                              java.lang.reflect.InvocationTargetException

Iterate all the fields passed in. Each field calls putFieldsValueDependsOnSaveOrUpdate(LitePalSupport, java.lang.reflect.Field, android.content.ContentValues) if it's not id field.

参数:

baseObj - Current model to persist or update.

supportedFields - List of all supported fields.

values - To store data of current model for persisting or updating.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.NoSuchMethodException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

putContentValuesForSave

protected void putContentValuesForSave(LitePalSupport baseObj,
                                       java.lang.reflect.Field field,
                                       android.content.ContentValues values)
                                throws java.lang.SecurityException,
                                       java.lang.IllegalArgumentException,
                                       java.lang.IllegalAccessException,
                                       java.lang.reflect.InvocationTargetException

This method deals with the putting values job into ContentValues. The ContentValues has put method to set data. But we do not know we should use which put method cause the field type isn't clear. So the reflection API is necessary here to put values into ContentValues with dynamically getting field type to put value.

参数:

baseObj - The class of base object.

field - Field to put into ContentValues.

values - To store data of current model for persisting or updating.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

putContentValuesForUpdate

protected void putContentValuesForUpdate(LitePalSupport baseObj,
                                         java.lang.reflect.Field field,
                                         android.content.ContentValues values)
                                  throws java.lang.SecurityException,
                                         java.lang.IllegalArgumentException,
                                         java.lang.IllegalAccessException,
                                         java.lang.reflect.InvocationTargetException

putContentValuesForUpdate operation is almost same with putContentValuesForSave, except allowing put null fieldValue into database, which is made for LitePalSupport.setToDefault(java.lang.String) function.

参数:

baseObj - The class of base object.

field - Field to put into ContentValues.

values - To store data of current model for persisting or updating.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

encryptValue

protected java.lang.Object encryptValue(java.lang.String algorithm,
                                        java.lang.Object fieldValue)

Encrypt the field value with targeted algorithm.

参数:

algorithm - The algorithm to encrypt value.

fieldValue - Field value to encrypt.

返回:

Encrypted value by targeted algorithm.

getFieldValue

protected java.lang.Object getFieldValue(LitePalSupport dataSupport,
                                         java.lang.reflect.Field field)
                                  throws java.lang.SecurityException,
                                         java.lang.IllegalArgumentException,
                                         java.lang.IllegalAccessException

Get the field value for model.

参数:

dataSupport - The model to get method from.

field - Use to generate getter method name.

返回:

The value returned by getter method.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

setFieldValue

protected void setFieldValue(LitePalSupport dataSupport,
                             java.lang.reflect.Field field,
                             java.lang.Object parameter)
                      throws java.lang.SecurityException,
                             java.lang.IllegalArgumentException,
                             java.lang.IllegalAccessException

Set the field value for model.

参数:

dataSupport - The model to set method to.

field - Use to generate setter method name.

parameter - The parameter to invoke setter method.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

analyzeAssociatedModels

protected void analyzeAssociatedModels(LitePalSupport baseObj,
                                       java.util.Collection<AssociationsInfo> associationInfos)

Find all the associated models of currently model. Then add all the associated models into baseObj.

参数:

baseObj - The class of base object.

getAssociatedModel

protected LitePalSupport getAssociatedModel(LitePalSupport baseObj,
                                            AssociationsInfo associationInfo)
                                     throws java.lang.SecurityException,
                                            java.lang.IllegalArgumentException,
                                            java.lang.IllegalAccessException

Get the associated model.

参数:

baseObj - The instance of self model.

associationInfo - To get the associated model.

返回:

The associated model of self model by analyzing associationInfo.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

getAssociatedModels

protected java.util.Collection<LitePalSupport> getAssociatedModels(LitePalSupport baseObj,
                                                                   AssociationsInfo associationInfo)
                                                            throws java.lang.SecurityException,
                                                                   java.lang.IllegalArgumentException,
                                                                   java.lang.IllegalAccessException

Get the associated models collection. When it comes to many2one or many2many association. A model may have lots of associated models.

参数:

baseObj - The instance of self model.

associationInfo - To get the associated models collection.

返回:

The associated models collection of self model by analyzing associationInfo.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.IllegalAccessException

getEmptyModel

protected LitePalSupport getEmptyModel(LitePalSupport baseObj)

Create an empty instance of baseObj if it hasn't created one yet. If there's already an empty model existed in tempEmptyModel, no need to create a new one.

参数:

baseObj - Current model to update.

返回:

An empty instance of baseObj.

getWhereClause

protected java.lang.String getWhereClause(java.lang.String... conditions)

Get the WHERE clause to apply when updating or deleting multiple rows.

参数:

conditions - A string array representing the WHERE part of an SQL statement.

返回:

The WHERE clause to apply when updating or deleting multiple rows.

getWhereArgs

protected java.lang.String[] getWhereArgs(java.lang.String... conditions)

Get the WHERE arguments to fill into where clause when updating or deleting multiple rows.

参数:

conditions - A string array representing the WHERE part of an SQL statement.

返回:

The WHERE arguments to fill into where clause when updating or deleting multiple rows.

isAffectAllLines

protected boolean isAffectAllLines(java.lang.Object... conditions)

Check the passing conditions represent to affect all lines or not.
Do not pass anything to the conditions parameter means affect all lines.

参数:

conditions - An array representing the WHERE part of an SQL statement.

返回:

Affect all lines or not.

getWhereOfIdsWithOr

protected java.lang.String getWhereOfIdsWithOr(java.util.Collection<java.lang.Long> ids)

Get the where clause by the passed in id collection to apply multiple rows.

参数:

ids - The id collection.

返回:

The where clause to execute.

getWhereOfIdsWithOr

protected java.lang.String getWhereOfIdsWithOr(long... ids)

Get the where clause by the passed in id array to apply multiple rows.

参数:

ids - The id collection.

返回:

The where clause to execute.

shouldGetOrSet

protected boolean shouldGetOrSet(LitePalSupport dataSupport,
                                 java.lang.reflect.Field field)

When executing getFieldValue(LitePalSupport, Field) or setFieldValue(LitePalSupport, Field, Object), the dataSupport and field passed in should be protected from null value.

参数:

dataSupport - The object to execute set or get method.

field - The field of generating set and get methods.

返回:

True if dataSupport and field are not null, false otherwise.

getIntermediateTableName

protected java.lang.String getIntermediateTableName(LitePalSupport baseObj,
                                                    java.lang.String associatedTableName)

Get the name of intermediate join table.

参数:

baseObj - Current model.

associatedTableName - The name of associated table.

返回:

The name of intermediate join table.

getTableName

protected java.lang.String getTableName(java.lang.Class<?> modelClass)

Get the simple name of modelClass. Then change the case by the setting rule in litepal.xml as table name.

参数:

modelClass - Class of model to get table name from.

返回:

The table name of model.

createInstanceFromClass

protected java.lang.Object createInstanceFromClass(java.lang.Class<?> modelClass)

Creates an instance from the passed in class. It will always create an instance no matter how the constructor defines in the class file. A best suit constructor will be find by calling findBestSuitConstructor(Class) method.

参数:

modelClass - The class to create instance.

返回:

An instance by the passed in class.

findBestSuitConstructor

protected java.lang.reflect.Constructor<?> findBestSuitConstructor(java.lang.Class<?> modelClass)

Finds the best suit constructor for creating an instance of a class. The principle is that the constructor with least parameters and has no self type parameter will be the best suit one to create instance.

参数:

modelClass - To get constructors from.

返回:

The best suit constructor.

getConstructorParams

protected java.lang.Object[] getConstructorParams(java.lang.Class<?> modelClass,
                                                  java.lang.reflect.Constructor<?> constructor)

Depends on the passed in constructor, creating a parameters array with initialized values for the constructor.

参数:

modelClass - The original class the this constructor belongs to.

constructor - The constructor to get parameters for it.

返回:

A parameters array with initialized values.

setValueToModel

protected void setValueToModel(java.lang.Object modelInstance,
                               java.util.List<java.lang.reflect.Field> supportedFields,
                               java.util.List<AssociationsInfo> foreignKeyAssociations,
                               android.database.Cursor cursor,
                               android.util.SparseArray<org.litepal.crud.DataHandler.QueryInfoCache> sparseArray)
                        throws java.lang.SecurityException,
                               java.lang.IllegalArgumentException,
                               java.lang.NoSuchMethodException,
                               java.lang.IllegalAccessException,
                               java.lang.reflect.InvocationTargetException

Get value from database by cursor, then set the value into modelInstance.

参数:

modelInstance - The model to set into.

supportedFields - Corresponding to each column in database.

foreignKeyAssociations - Associated classes which have foreign keys in the current model's table.

cursor - Use to get value from database.

sparseArray - Use SparseArray to cache the query information at first loop. Then the rest loop can get query information directly to speed up.

抛出:

java.lang.SecurityException

java.lang.IllegalArgumentException

java.lang.NoSuchMethodException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

setGenericValueToModel

protected void setGenericValueToModel(LitePalSupport baseObj,
                                      java.util.List<java.lang.reflect.Field> supportedGenericFields,
                                      java.util.Map<java.lang.reflect.Field,GenericModel> genericModelMap)
                               throws java.lang.NoSuchMethodException,
                                      java.lang.IllegalAccessException,
                                      java.lang.reflect.InvocationTargetException

Get generic value from generic tables, then set the value into the baseObj.

参数:

baseObj - The model to set into.

supportedGenericFields - List of all supported generic fields.

genericModelMap - Use HashMap to cache the query information at first loop. Then the rest loop can get query information directly to speed up.

抛出:

java.lang.NoSuchMethodException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

getForeignKeyAssociations

protected java.util.List<AssociationsInfo> getForeignKeyAssociations(java.lang.String className,
                                                                     boolean isEager)

Get the foreign key associations of the specified class.

参数:

className - The full class name.

isEager - True to load the associated models, false not.

返回:

The foreign key associations of the specified class

getParameterTypes

protected java.lang.Class<?>[] getParameterTypes(java.lang.reflect.Field field,
                                                 java.lang.Object fieldValue,
                                                 java.lang.Object[] parameters)

Get the types of parameters for ContentValues.put(java.lang.String, java.lang.String). Need two parameters. First is String type for key. Second is depend on field for value.

参数:

field - The field to get parameter type.

fieldValue - Value of the field. Only used to convert to String when the field is char.

parameters - If the field is char, convert the value to String at index 1.

返回:

The types of parameters for ContentValues.put(java.lang.String, java.lang.String).

makeGetterMethodName

protected java.lang.String makeGetterMethodName(java.lang.reflect.Field field)

Generate the getter method name by field, following the Android Studio rule.

参数:

field - The field to generate getter method from.

返回:

The generated getter method name.

makeSetterMethodName

protected java.lang.String makeSetterMethodName(java.lang.reflect.Field field)

Generate the setter method name by field, following the Android Studio rule.

参数:

field - The field to generate setter method from.

返回:

The generated setter method name.

decryptValue

protected java.lang.Object decryptValue(java.lang.String algorithm,
                                        java.lang.Object fieldValue)

Decrypt the field value with targeted algorithm.

参数:

algorithm - The algorithm to decrypt value.

fieldValue - Field value to decrypt.

返回:

Decrypted value by targeted algorithm.