====== Session Control ======
**''public class SessionControl''**\\
**''extends java.lang.Object''**\\
\\
Class for controlling the active session of the application, including process users input, run the reasoner (DLV engine), read/write to/from data layer (database), and return an output to users.\\

Functions:
  * Read/write schemas from/to database
  * Write objects to database (via Hibernate)
  * Add/edit/delete schema
  * Add/edit/delete relation of the schema
  * Add/edit/delete foreign key of the schema
  * Add/edit/delete finite domain constraint
  * Add/edit/delete TC statement
  * Add/edit/delete query
  * Displaying information of query reasoning result
  * User login/logout/register functions
  * Import pre-defined sample schema
Deprecated functions:
  * Read/write schemas from/to file
  * Restore saved schema

===== Class Attributes =====
<code java>
private java.util.ArrayList<SessionSchema> sessionLocalSchemas
private java.util.ArrayList<SessionSchema> sessionRemoteSchemas

private java.lang.String fileStorageUrl

private DatabaseConnector dbConnector
private HibernateConnector hibernateConnector
private java.util.ArrayList<DatabaseConnector> remoteDbConnector

private java.util.ArrayList<TCStatement> tcSuggestions

private SessionSchema currentSchema
private java.lang.String currentUser

private long executionTime
private boolean webApp
private java.lang.String dlvPath
</code>
===== Class Constructors  =====
==== SessionControl====
<code java>
public SessionControl()
               throws javax.naming.NamingException
</code>
**Throws:**
  * javax.naming.NamingException

===== Class Methods =====

==== readDBSchemas====
<code java>
public void readDBSchemas(boolean localSchema)
                   throws java.lang.ClassNotFoundException,
                          java.io.IOException
</code>
Read saved schemas from database, then set session schemas (sessionLocalSchemas & sessionRemoteSchemas).\\
//Called in [[magik-demo:developer:magik-business-logic#schema/index.jsp|schema/index.jsp]].//\\
**Throws:**
  * java.lang.ClassNotFoundException
  * java.io.IOException

----
==== addDbConnection====
<code java>
public void addDbConnection(java.lang.String dbUrl,
                   java.lang.String dbUser,
                   java.lang.String dbPassword)
                     throws java.sql.SQLException,
                            java.lang.ClassNotFoundException
</code>
Establish remote database connection, read all available schemas under that remote database, then add the schemas into local database.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/index.jsp|schema/index.jsp]], action: adddb.//\\
**Throws:**
  * java.lang.ClassNotFoundException
  * java.io.IOException
  * java.sql.SQLException

----

==== addDbSchema====
<code java>
public void addDbSchema(it.unibz.inf.magik.web.SessionSchema ss) 
                     throws java.sql.SQLException
</code>
Add the remote schema into local database. \\
//Called in [[magik-demo:developer:magik-business-logic#schema/editRelation.jsp|schema/editRelation.jsp]], action: connect.//\\
**Throws:**
  * java.sql.SQLException

----
==== hibernateSaveObject====
<code java>
private void hibernateSaveObject(java.lang.Object o)
</code>
Write objects to database via Hibernate.\\
**Parameters:**
  * o - object to be saved

----
==== deleteSchema====
<code java>
public void deleteSchema(java.lang.String schemaName)
                  throws java.sql.SQLException
</code>
Find schema by name then delete it from the list of schemas.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/index.jsp|schema/index.jsp]], action: delete.//\\
**Parameters:**
  * schemaName - schema name
**Throws:**
  * java.sql.SQLException

----
==== addSchema====
<code java>
public void addSchema(SessionSchema currSchema,
             java.lang.String newSchemaName)
               throws java.sql.SQLException
</code>
Add new schema.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/index.jsp|schema/index.jsp]], action: add.//\\
**Parameters:**
  * currSchema - schema to be added
  * newSchemaName - new schema name
**Throws:**
  * java.sql.SQLException

----
==== updateSchema====
<code java>
public void updateSchema(Schema currSchema,
                java.lang.String newSchemaName)
                  throws java.sql.SQLException
</code>
Find schema by name then update it.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/index.jsp|schema/index.jsp]], action: edit.//\\
**Parameters:**
  * currSchema - schema to be updated
  * newSchemaName - new schema name
**Throws:**
  * java.sql.SQLException

----
==== deleteRelation====
<code java>
public void deleteRelation(java.lang.String relName)
</code>
Find relation by name then delete it from the list of relations.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/edit.jsp|schema/edit.jsp]], action: delete.//\\
**Parameters:**
  * relName - name of relation

----
==== addRelation====
<code java>
public void addRelation(java.lang.String relName,
               java.lang.String keys,
               java.lang.String description)
                 throws ContextException
</code>
Add new relation.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/edit.jsp|schema/edit.jsp]], action: addrel.//\\
**Parameters:**
  * relName - relation name
  * keys - relation keys
  * desc - relation description
**Throws:**
  * ContextException

----
==== updateRelation====
<code java>
public void updateRelation(java.lang.String oldRelName,
                  java.lang.String relName,
                  java.lang.String keys,
                  java.lang.String description)
                    throws ContextException
</code>
Find relation by name then update it.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/edit.jsp|schema/edit.jsp]], action: editrel.//\\
**Parameters:**
  * oldRelName - relation name to be updated
  * relName - new relation name
  * keys - new relation keys
  * desc - new relation description
**Throws:**
  * ContextException

----
==== deleteForeignKey====
<code java>
public void deleteForeignKey(int fkidx)
</code>
Delete foreign key from array of foreign keys, by index.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: delete.//\\
**Parameters:**
  * fkidx - index of foreign key to be deleted

----
==== addForeignKey====
<code java>
public void addForeignKey(int sourceRelIdx,
                 int targetRelIdx,
                 java.lang.String sourceAttr)
                   throws ContextException
</code>
Add new foreign key.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: addfk.//\\
**Parameters:**
  * sourceRel - source relation
  * targetRel - target relation
  * sourceAttr - source attribute
**Throws:**
  * ContextException

----
==== updateForeignKey====
<code java>
public void updateForeignKey(int fkIdx,
                    int sourceRelIdx,
                    int targetRelIdx,
                    java.lang.String sourceAttr)
                      throws ContextException
</code>
Update existing foreign key.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: editfk.//\\
**Parameters:**
  * fkIdx - index of foreign key to be updated
  * sourceRel - new source relation
  * targetRel - new target relation
  * sourceAttr - new source attribute
**Throws:**
  * ContextException

----
==== readFK====
<code java>
public java.util.ArrayList<ForeignKey> readFK()
                                       throws java.sql.SQLException
</code>
Read foreign keys (from database schema and virtual foreign keys added by user).\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/showFK.jsp|constraints/showFK.jsp]].//\\
**Returns:**
  * arrFK list of foreign keys
**Throws:**
  * java.sql.SQLException

----
==== deleteFDC====
<code java>
public void deleteFDC(int fdcIdx)
</code>
Delete finite domain constraint from array of finite domain constraints, by index.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: delete.//\\
**Parameters:**
  * fkidx - index of finite domain constraint to be deleted

----
==== addFDC====
<code java>
public void addFDC(int relIdx,
          java.lang.String column,
          java.lang.String values)
            throws ContextException
</code>
Add new finite domain constraint.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: addfdc.//\\
**Parameters:**
  * relIdx - relation index over which finite domain constraint is defined
  * column - position of the constrained argument in the containing relation
  * values - values allowed for the argument
**Throws:**
  * ContextException

----
==== updateFDC====
<code java>
public void updateFDC(int fdcIdx,
             int relIdx,
             java.lang.String column,
             java.lang.String values)
               throws ContextException
</code>
Update existing finite domain constraint.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: editfdc.//\\
**Parameters:**
  * fdcIdx - index of finite domain constraint to be updated
  * relIdx - relation index over which finite domain constraint is defined
  * column - position of the constrained argument in the containing relation
  * values - values allowed for the argument
**Throws:**
  * ContextException

----
==== readFDC====
<code java>
public java.util.ArrayList<FiniteDomainConstraint> readFDC()
</code>
Read finite domain constraints.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/showFDC.jsp|constraints/showFDC.jsp]].//\\
**Returns:**
  * arrFDC list of finite domain constraints
**Throws:**
  * java.sql.SQLException

----
==== deleteTCStatement ====
<code java>
public void deleteTCStatement(int tcidx)
</code>
Delete TC statement from array of TC statements, by index.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: delete.//\\
**Parameters:**
  * tcidx - index of TC statement to be deleted

----
==== addTCStatement ====
<code java>
public void addTCStatement(int relIdx,
                  java.lang.String headTerms,
                  java.lang.String condition,
                  java.lang.String description,
                  java.lang.String name)
                    throws ContextException
</code>
Add new TC Statement.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: addtc.//\\
**Parameters:**
   * relIdx - relation over which the TC statement is defined
   * headTerms - head SimpleTerms x of the relation R
   * condition - condition G of the TC statement
   * description - description of the TC statement
   * name - name of the TC statement
**Throws:**
  * ContextException

----
==== addTCStatement ====
<code java>
public void addTCStatement(TCStatement tcs)
</code>
Add new TC Statement (add the suggested TCStatement after reasoning).\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: reason.//\\
**Parameters:**
  * tcs - TCStatement to be added

----
==== updateTCStatement ====
<code java>
public void updateTCStatement(int tcIdx,
                     int relIdx,
                     java.lang.String headTerms,
                     java.lang.String condition,
                     java.lang.String description,
                     java.lang.String tcName)
                       throws ContextException
</code>
Update existing TC statement.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: edittc.//\\
**Parameters:**
  * tcIdx - index of TC statement to be updated
  * relIdx - relation over which the TC statement is defined
  * headTerms - head SimpleTerms x of the relation R
  * condition - condition G of the TC statement
  * description description of the TC statement
  * tcName name of the TC statement
**Throws:**
  * ContextException

----
==== readTCS====
<code java>
public java.util.ArrayList<TCStatement> readTCS()
</code>
Read TC statements.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/showTC.jsp|constraints/showTC.jsp]].//\\
**Returns:**
  * arrTC list of TC statements
**Throws:**
  * java.sql.SQLException

----
==== deleteQuery ====
<code java>
public void deleteQuery(int qidx)
</code>
Delete query from array of queries, by index.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: delete.//\\
**Parameters:**
  * qidx - index of query to be deleted

----
==== addSQLQuery====
<code java>
public void addSQLQuery(java.lang.String qName,
               java.lang.String values,
               java.lang.String desc)
                 throws ParseSQLQueryException, ContextException
</code>
Add new query (from SQL format).\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: addq.//\\
**Parameters:**
  * qName - name of the query
  * values - body of the query (SQL)
  * desc - description of the query
**Throws:**
  * ParseSQLQueryException
  * ContextException

----
==== addSQLQuery====
<code java>
public void addSQLQuery(Query q)
</code>
Add new query (add the suggested query after reasoning).\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: reason.//\\
**Parameters:**
  * q - query to add


----
==== updateSQLQuery====
<code java>
public void updateSQLQuery(int qIdx,
                  java.lang.String qName,
                  java.lang.String values,
                  java.lang.String desc)
                    throws ParseSQLQueryException, ContextException
</code>
Update existing query (from SQL format).\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: editq.//\\
**Parameters:**
  * qIdx - index of query to be updated
  * qName - name of the query
  * values - body of the query (SQL)
  * desc - description of the query
**Throws:**
  * ParseSQLQueryException
  * ContextException

----
==== readQuery====
<code java>
public java.util.ArrayList<Query> readQuery()
                                     throws ParseSQLQueryException
</code>
Read queries.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/showQuery.jsp|constraints/showQuery.jsp]].//\\
**Returns:**
  * arrQ list of queries
**Throws:**
  * ParseSQLQueryException

----
==== encodingProgram====
<code java>
public java.lang.String encodingProgram(SessionSchema currSchema,
                               Schema reasonSchema,
                               int selQueryIdx)
                                 throws it.unical.mat.wrapper.DLVInvocationException,
                                        java.io.IOException,
                                        CycleException,
                                        PrimaryKeyViolationException
</code>
Get the encoding program.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: reason.//\\
**Returns:**
  * result string of encoding program
**Throws:**
  * it.unical.mat.wrapper.DLVInvocationException
  * java.io.IOException
  * CycleException
  * PrimaryKeyViolationException

----
==== printQueryResultHTML====
<code java>
public java.lang.String printQueryResultHTML(SessionSchema currSchema,
                                    int selQueryIdx)
                                      throws java.sql.SQLException,
                                             java.lang.ClassNotFoundException
</code>
Display the result of evaluating SQL query.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: reason.//\\
**Returns:**
  * result string of query evaluation result displayed in HTML table
**Throws:**
  * java.sql.SQLException
  * java.lang.ClassNotFoundException
  * java.IO.IOException

----
==== isQueryComplete====
<code java>
public boolean isQueryComplete(SessionSchema currSchema,
                      Schema reasonSchema,
                      int selQueryIdx, 
                      int maxQSpecSize)
                        throws it.unical.mat.wrapper.DLVInvocationException,
                               java.io.IOException,
                               CycleException,
                               PrimaryKeyViolationException
                               ContextException 
	                       ParseSQLQueryException 
</code>
Get the result of query completeness reasoning.\\
//Called in [[magik-demo:developer:magik-business-logic#constraints/index.jsp|constraints/index.jsp]], action: reason.//\\
**Parameters**
  * currSchema - current Schema
  * reasonSchema - schema on where it has to reason
  * selQueryIdx - id of the selected query that we want to analyze
  * maxQSpecSize - max difference of depth between original query and the specialize query
**Returns:**
  * isComplete true if query is complete, false otherwise
**Throws:**
  * it.unical.mat.wrapper.DLVInvocationException
  * java.io.IOException
  * CycleException
  * PrimaryKeyViolationException
  * ContextException 
  * ParseSQLQueryException 

----

==== approximateQuery ====
<code java>
public void approximateQuery(Query q,
                      Schema currSchema,
                      int maxQSpecSize)
                        throws it.unical.mat.wrapper.DLVInvocationException,
                               java.io.IOException,
                               CycleException,
                               PrimaryKeyViolationException
                               ContextException 
	                       ParseSQLQueryException 
</code>
Get the complete query approximations of incomplete query.\\
**Parameters**
  * q - incomplete query
  * currSchema - current Schema
  * maxQSpecSize max difference of depth between original query and the specialize query
**Throws:**
  * it.unical.mat.wrapper.DLVInvocationException
  * java.io.IOException
  * CycleException
  * PrimaryKeyViolationException
  * ContextException 
  * ParseSQLQueryException 

----


==== importSampleSchema====
<code java>
public void importSampleSchema(java.lang.String appPath)
                        throws java.sql.SQLException,
                               ContextException,
                               ParseSQLQueryException,
                               java.io.IOException
</code>
Import pre-defined sample schema (school schema), including the sample constraints.\\
//Called in [[magik-demo:developer:magik-business-logic#schema/index.jsp|schema/index.jsp]], action: import.//\\
**Parameters:**
  * appPath - application path
**Throws:**
  * java.sql.SQLException
  * ContextException
  * ParseSQLQueryException
  * java.io.IOException


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