org.apache.empire.db.DBRowSet Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.empire.db;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.empire.commons.ObjectUtils;
import org.apache.empire.commons.StringUtils;
import org.apache.empire.data.Column;
import org.apache.empire.data.DataType;
import org.apache.empire.db.DBRelation.DBCascadeAction;
import org.apache.empire.db.DBRelation.DBReference;
import org.apache.empire.db.exceptions.FieldNotNullException;
import org.apache.empire.db.exceptions.NoPrimaryKeyException;
import org.apache.empire.db.exceptions.QueryNoResultException;
import org.apache.empire.db.exceptions.InvalidKeyException;
import org.apache.empire.db.exceptions.RecordNotFoundException;
import org.apache.empire.db.exceptions.RecordUpdateFailedException;
import org.apache.empire.db.exceptions.RecordUpdateInvalidException;
import org.apache.empire.db.expr.column.DBCountExpr;
import org.apache.empire.exceptions.InvalidArgumentException;
import org.apache.empire.exceptions.ItemNotFoundException;
import org.apache.empire.exceptions.NotSupportedException;
import org.apache.empire.exceptions.ObjectNotValidException;
import org.apache.empire.exceptions.UnexpectedReturnValueException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class is the base class for all the DBTable,
* DBView and DBQuery classes this class contains all the columns of the
* tables, views or queries
*
*
*
*/
public abstract class DBRowSet extends DBExpr
{
private final static long serialVersionUID = 1L;
/**
* This class is used to set the auto generated key of a record if the database does not support sequences.
* It is used with the executeSQL function and only required for insert statements
*/
private static class DBSetGenKey implements DBDatabaseDriver.DBSetGenKeys
{
private Object[] fields;
private int index;
public DBSetGenKey(Object[] fields, int index)
{
this.fields = fields;
this.index = index;
}
public void set(Object value)
{
fields[index]=value;
}
}
// Logger
protected static final Logger log = LoggerFactory.getLogger(DBRowSet.class);
// Members
protected final transient DBDatabase db;
protected String comment = null;
protected DBIndex primaryKey = null;
protected DBColumn timestampColumn = null; // Use SetUpdateTimestamp!
protected Map columnReferences = null;
// The column List
protected List columns = new ArrayList();
/**
* Constructs a DBRecord object set the current database object.
* @param db the database object
*/
public DBRowSet(DBDatabase db)
{
this.db = db;
}
/**
* Gets an identifier for this RowSet Object
* @return the rowset identifier
*/
public String getId()
{
return db.getId()+"."+getName();
}
/**
* returns a rowset by its identifier
* @param rowsetId the id of the rowset
* @return the rowset object
*/
public static DBRowSet findById(String rowsetId)
{
int i = rowsetId.lastIndexOf('.');
if (i<0)
throw new InvalidArgumentException("rowsetId", rowsetId);
// database suchen
String dbid = rowsetId.substring(0, i);
DBDatabase db = DBDatabase.findById(dbid);
if (db==null)
throw new ItemNotFoundException(dbid);
// rowset suchen
String rsname = rowsetId.substring(i+1);
DBRowSet rset = db.getRowSet(rsname);
if (rset==null)
throw new ItemNotFoundException(rowsetId);
return rset;
}
/**
* Custom serialization for transient database.
*/
private void writeObject(ObjectOutputStream strm) throws IOException
{
if (db==null)
{ // No database
strm.writeObject("");
strm.defaultWriteObject();
return;
}
String dbid = db.getId();
strm.writeObject(dbid);
if (log.isInfoEnabled())
log.info("Serialization: reading DBRowSet "+dbid);
// write the rest
strm.defaultWriteObject();
}
/**
* Custom deserialization for transient database.
*/
private void readObject(ObjectInputStream strm) throws IOException, ClassNotFoundException,
SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException
{
String dbid = String.valueOf(strm.readObject());
if (StringUtils.isNotEmpty(dbid))
{ // Find database
if (log.isInfoEnabled())
log.info("Serialization: reading DBRowSet "+dbid);
// find database
DBDatabase sdb = DBDatabase.findById(dbid);
if (sdb==null)
throw new ClassNotFoundException(dbid);
// set final field
Field f = DBRowSet.class.getDeclaredField("db");
f.setAccessible(true);
f.set(this, sdb);
f.setAccessible(false);
}
// read the rest
strm.defaultReadObject();
}
@Override
public int hashCode()
{
String nameWithAlias = getFullName()+"_"+getAlias();
return nameWithAlias.hashCode();
}
@Override
public boolean equals(Object other)
{
if (other==this)
return true;
if (db==null)
return super.equals(other);
if (other instanceof DBRowSet)
{ // Database and name must match
DBRowSet r = (DBRowSet) other;
if (db.equals(r.getDatabase())==false)
return false;
// Check Alias
if (getAlias()==null)
return super.equals(other);
// check for equal names
return StringUtils.compareEqual(getAlias(), r.getAlias(), true);
}
return false;
}
// ------- Abstract Methods -------
public abstract String getName();
public abstract String getAlias();
public abstract boolean isUpdateable();
public abstract void createRecord(DBRecord rec, Connection conn);
public abstract void deleteRecord(Object[] keys, Connection conn);
/**
* Returns the full qualified name of the rowset.
*
* @return the full qualified name
*/
public String getFullName()
{
String name = getName();
String schema = db.getSchema();
return (schema!=null) ? schema+"."+name : name;
}
/**
* @see org.apache.empire.db.DBExpr#addReferencedColumns(Set)
*/
@Override
public void addReferencedColumns(Set list)
{
list.addAll(columns);
}
/**
* Returns the current DBDatabase object.
*
* @return the current DBDatabase object
*/
@Override
public final DBDatabase getDatabase()
{
return db;
}
/**
* Gets all columns of this rowset (e.g. for cmd.select()).
*
* @return all columns of this rowset
*/
public List getColumns()
{
return columns;
}
/**
* Gets the index of a particular column expression.
*
* @param column column the DBColumn to get the index for
*
* @return the position of a column expression
*/
public int getColumnIndex(DBColumn column)
{
return columns.indexOf(column);
}
/**
* Gets the index of a particular column expression.
*
* @param column the Column to get the index for
*
* @return the position of a column expression
*/
public final int getColumnIndex(Column column)
{
return getColumnIndex((DBColumn)column);
}
/**
* Returns a DBColumn object by a specified index value.
*
* @param iColumn the index to get the DBColumn for
*
* @return the index value
*/
public DBColumn getColumn(int iColumn)
{
if (iColumn < 0 || iColumn >= columns.size())
return null;
return columns.get(iColumn);
}
/**
* Gets the column Expression with a particular name.
*
* @param name the name of the column to look for
*
* @return the column Expression at position
*/
public DBColumn getColumn(String name)
{
for (int i = 0; i < columns.size(); i++)
{
DBColumn col = columns.get(i);
if (col.getName().equalsIgnoreCase(name))
return col;
}
return null;
}
/**
* Checks whether a column is read only or writable.
* Only the timestamp column is read only by default.
* The primary is read only if the column is of type.
*
* @param col the column object
*
* @return a new DBCountExpr object
*/
public boolean isColumnReadOnly(DBColumn col)
{
if (getColumnIndex(col)<0)
return true; // not found!
if (col.isAutoGenerated() || col==timestampColumn)
return true; // timestamp column
// Check Update Column
return (col.isReadOnly());
}
/**
* Returns an array of all primary key columns.
*
* @return an array of all primary key columns
*/
public DBColumn[] getKeyColumns()
{
return ((primaryKey != null) ? primaryKey.getColumns() : null);
}
/**
* Checks whether a given column is part of the primary key for this RowSet
* @param column the column to check
* @return true if the column is part of the primary key or false otherwise
*/
public boolean isKeyColumn(DBColumn column)
{
DBColumn[] keyColumns = getKeyColumns();
for (int i=0; i getColumnReferences()
{
return columnReferences;
}
/**
* Adds a column reference to the list of table references.
* This method is internally called from DBDatabase.addReleation().
*
* @param source a column reference for one of this table's column
* @param target the target column to which the source column references
*/
protected void addColumnReference(DBColumn source, DBColumn target)
{
if (source.getRowSet()!=this)
throw new InvalidArgumentException("column", source.getFullName());
if (columnReferences== null)
columnReferences = new HashMap();
// Check if column is already there
columnReferences.put(source, target);
}
/**
* Returns a new DBCountExpr object.
*
* @return a new DBCountExpr object
*/
public DBColumnExpr count()
{
return new DBCountExpr(this);
}
/**
* Returns the sql phrase for renaming tables.
* usually just a space character ' '
*
* @return the table rename phrase
*/
protected String getRenameTablePhrase()
{
if (db==null || db.driver==null)
return " ";
return db.driver.getSQLPhrase(DBDatabaseDriver.SQL_RENAME_TABLE);
}
/**
* Returns a array of primary key columns by a specified DBRecord object.
*
* @param rec the DBRecord object, contains all fields and the field properties
* @return a array of primary key columns
*/
public Object[] getRecordKey(DBRecord rec)
{
if (rec.getRowSet() != this)
return null; // Invalid Argument
if (primaryKey == null)
return null; // No primary key
// Check Columns
DBColumn[] keyColumns = primaryKey.getColumns();
Object[] keys = new Object[keyColumns.length];
for (int i = 0; i < keyColumns.length; i++)
{
keys[i] = rec.getValue(keyColumns[i]);
if (keys[i] == null)
{ // Primary Key not set
log.warn("getRecordKey: " + getName() + " primary key value is null!");
}
}
return keys;
}
/**
* Initialize this DBRowSet object and sets it's initial state.
*
* @param rec the DBRecord object to initialize this DBRowSet object
* @param state the state of this DBRowSet object
*/
protected void prepareInitRecord(DBRecord rec, Object rowSetData, boolean insert)
{
if (rec==null)
throw new InvalidArgumentException("rec", rec);
if (columns.size() < 1)
throw new ObjectNotValidException(this);
// Init
rec.initData(this, rowSetData, insert);
}
/**
* Initializes a DBRecord for this RowSet and sets primary key values (the Object[] keyValues).
* The record may then be modified and updated.
*
* @param rec the Record object
* @param keyValues an array of the primary key columns
*/
public void initRecord(DBRecord rec, Object[] keyValues, boolean insert)
{
// Prepare
prepareInitRecord(rec, null, insert);
// Initialize all Fields
Object[] fields = rec.getFields();
for (int i = 0; i < fields.length; i++)
fields[i] = ObjectUtils.NO_VALUE;
// Init Key Values
if (keyValues != null && primaryKey != null)
{
// Check Columns
DBColumn[] keyColumns = primaryKey.getColumns();
for (int i = 0; i < keyColumns.length; i++)
{ // Ignore Validity Checks
int field = getColumnIndex(keyColumns[i]);
fields[field] = keyValues[i];
}
}
// Init
completeInitRecord(rec);
}
/**
* Initializes a DBRecord for this rowset using the record data provided (i.e. from a DBReader)
* The record may then be modified and updated.
* At least all primary key columns must be supplied.
* We strongly recommend to supply the value of the update timestamp column in order to detect concurrent changes.
* Fields for which no value is supplied with the recData paramter are set to NO_VALUE
*
* @param rec the record object
* @param recData the record data from which to initialized the record
*/
public void initRecord(DBRecord rec, DBRecordData recData)
{
// Initialize the record
prepareInitRecord(rec, null, false);
// Get Record Field Values
Object[] fields = rec.getFields();
for (int i = 0; i < fields.length; i++)
{
// Read a value
DBColumn column = columns.get(i);
int rdi = recData.getFieldIndex(column);
if (rdi<0)
{ // Field not available in Record Data
if (primaryKey!=null && primaryKey.contains(column))
{ // Error: Primary Key not supplied
throw new ItemNotFoundException(column.getName());
}
if (timestampColumn == column)
{ // Check the update Time Stamp
if (log.isInfoEnabled())
log.info(getName() + "No record timestamp value has been provided. Hence concurrent changes will not be detected.");
}
// Set to NO_VALUE
fields[i] = ObjectUtils.NO_VALUE;
}
else
{ // Get Field value
fields[i] = recData.getValue(rdi);
}
}
// Done
completeInitRecord(rec);
}
/**
* Completes the record initialization.
* Override this function to do post initialization processing.
*
* @param rec the DBRecord object to initialize
*/
protected void completeInitRecord(DBRecord rec)
{
rec.onRecordChanged();
}
/**
* Set the constraints for a single record from a supplied key
* @param cmd the command to which to add the constraints
* @param key the record key
* @return true if the constraints have been successfully set or false otherwise
*/
protected void setKeyConstraints(DBCommand cmd, Object[] key)
{
// Check Primary key
if (primaryKey == null )
throw new NoPrimaryKeyException(this); // Invalid Argument
// Check Columns
DBColumn[] keyColumns = primaryKey.getColumns();
if (key == null || key.length != keyColumns.length)
throw new InvalidKeyException(this, key); // Invalid Argument
// Add the key constraints
for (int i = 0; i < key.length; i++)
{ // prepare key value
Object value = key[i];
if (db.isPreparedStatementsEnabled())
value = cmd.addParam(keyColumns[i], value);
// set key column constraint
cmd.where(keyColumns[i].is(value));
}
}
/**
* Reads a single record from the database using the given command object.
* If a record is found the DBRecord object will hold all record data.
*
* @param rec the DBRecord object which holds the record data
* @param cmd the SQL-Command used to query the record
* @param conn a valid JDBC connection.
*/
protected void readRecord(DBRecord rec, DBCommand cmd, Connection conn)
{
DBReader reader = null;
try
{ // read record using a DBReader
reader = new DBReader();
reader.getRecordData(cmd, conn);
initRecord(rec, reader);
} finally {
reader.close();
}
}
/**
* Reads the record with the given primary key from the database.
* If the record cannot be found, a RecordNotFoundException is thrown.
*
* @param rec the DBRecord object which will hold the record data
* @param key the primary key values
* @param conn a valid JDBC connection.
*/
public void readRecord(DBRecord rec, Object[] key, Connection conn)
{
// Check Arguments
if (conn == null || rec == null)
throw new InvalidArgumentException("conn|rec", null);
// Select
DBCommand cmd = db.createCommand();
cmd.select(columns);
// Set key constraints
setKeyConstraints(cmd, key);
try {
// Read Record
readRecord(rec, cmd, conn);
} catch (QueryNoResultException e) {
// Translate exception
throw new RecordNotFoundException(this, key);
}
}
/**
* Returns true if the record exists in the database or false otherwise.
*
* @param key an array of the primary key columns
* @param conn a valid JDBC connection.
* @return true if the record exists or false otherwise
*/
public boolean recordExists(Object[] key, Connection conn)
{
// Check Arguments
if (conn == null)
throw new InvalidArgumentException("conn", conn);
// Select
DBCommand cmd = db.createCommand();
cmd.select(count());
// Set key constraints
setKeyConstraints(cmd, key);
// check exits
return (db.querySingleInt(cmd, 0, conn)==1);
}
/**
* Returns true if the record exists in the database or false otherwise.
*
* @param id id of the record
* @param conn a valid JDBC connection.
* @return true if the record exists or false otherwise
*/
public final boolean recordExists(Object id, Connection conn)
{
return recordExists(new Object[] { id }, conn);
}
/**
* Updates or Inserts a record in the database.
* Whether an update or insert is performed depends on the record state.
* Only modified fields will be inserted or updated in the database.
*
* If a timestamp-column is set for this RowSet then a constraint will be added in the
* update statement in order to detect concurrent changes.
* If the record has been modified by another user, an error of type
* DBErrors.RecordUpdateFailed will be set.
*
* @param rec the DBRecord object. contains all fields and the field properties
* @param conn a valid JDBC connection.
* @return true if the update was successful or false otherwise
*/
public void updateRecord(DBRecord rec, Connection conn)
{
// check updateable
if (isUpdateable()==false)
throw new NotSupportedException(this, "updateRecord");
// Check Arguments
if (rec == null)
throw new InvalidArgumentException("record", rec);
if (rec.isValid()==false)
throw new ObjectNotValidException(rec);
if (conn == null)
throw new InvalidArgumentException("conn", conn);
// Get the new Timestamp
String name = getName();
Timestamp timestamp = (timestampColumn!=null) ? db.getUpdateTimestamp(conn) : null;
DBDatabaseDriver.DBSetGenKeys setGenKey = null;
// Get the fields and the flags
Object[] fields = rec.getFields();
// Build SQL-Statement
DBCommand cmd = db.createCommand();
String sql = null;
int setCount = 0;
// Perform action
DBRecord.State recordState = rec.getState();
if (recordState==DBRecord.State.New)
{ // Insert Record
for (int i = 0; i < columns.size(); i++)
{ // search for the column
Object value = fields[i];
DBTableColumn col = (DBTableColumn) columns.get(i);
if (timestampColumn == col)
{ // Make sure the update timestamp column is set
cmd.set(col.to(timestamp));
continue;
}
boolean empty = ObjectUtils.isEmpty(value);
if (empty && col.isAutoGenerated())
{ // Check for AutoInc data type
if (col.getDataType()==DataType.AUTOINC &&
db.getDriver().isSupported(DBDriverFeature.SEQUENCES)==false)
{ // Obtain value via JDBC Statement.RETURN_GENERATED_KEYS
setGenKey = new DBSetGenKey(fields, i);
continue;
}
// get the auto-generated field value
fields[i] = value = col.getRecordDefaultValue(conn);
empty = ObjectUtils.isEmpty(value);
}
// Add the value to the command
if (empty==false)
{ // Check the value
if (col.isAutoGenerated()==false && rec.isValidateFieldValues())
col.validate(value);
// Insert a field
cmd.set(col.to(value));
setCount++;
}
else if (primaryKey!=null && primaryKey.contains(col))
{ // All primary key fields must be supplied
throw new FieldNotNullException(col);
}
else if (col.isRequired())
{ // Error Column is required!
throw new FieldNotNullException(col);
}
}
sql = cmd.getInsert();
}
else if (recordState==DBRecord.State.Modified)
{ // Update Record
if (primaryKey == null)
{ // Requires a primary key
log.error("updateRecord: " + name + " no primary key defined!");
throw new NoPrimaryKeyException(this);
}
for (int i = 0; i < columns.size(); i++)
{ // search for the column
Object value = fields[i];
boolean modified = rec.wasModified(i);
boolean empty = ObjectUtils.isEmpty(value);
DBTableColumn col = (DBTableColumn) columns.get(i);
if (primaryKey.contains(col))
{ // Check for Modification
if (modified == true)
{ // Requires a primary key
log.warn("updateRecord: " + name + " primary has been modified!");
}
// set pk constraint
if (db.isPreparedStatementsEnabled())
value = cmd.addParam(col, value);
cmd.where(col.is(value));
}
else if (timestampColumn == col)
{ // Check the update-timestamp
if (empty==false)
{ // set timestamp constraint
if (db.isPreparedStatementsEnabled())
value = cmd.addParam(col, value);
cmd.where(col.is(value));
}
else if (log.isDebugEnabled()) {
log.debug("updateRecord has no value for timestamp column. Concurrent changes will not be detected.");
}
cmd.set(col.to(timestamp));
}
else if (modified && value!=ObjectUtils.NO_VALUE)
{ // Update a field
if (col.isReadOnly())
log.warn("updateRecord: Read-only column '" + col.getName() + " has been modified!");
// Check the value
col.validate(value);
// Set the column
cmd.set(col.to(value));
setCount++;
}
}
// Get the SQL statement
sql = cmd.getUpdate();
}
else
{ // Not modified
log.info("updateRecord: " + name + " record has not been modified! ");
return;
}
if (setCount == 0)
{ // Nothing to update
log.info("updateRecord: " + name + " nothing to update or insert!");
return;
}
// Perform action
int affected = db.executeSQL(sql, cmd.getParamValues(), conn, setGenKey);
if (affected < 0)
{ // Update Failed
throw new UnexpectedReturnValueException(affected, "db.executeSQL()");
}
else if (affected == 0)
{ // Record not found
throw new RecordUpdateInvalidException(this, getRecordKey(rec));
}
else if (affected > 1)
{ // Multiple Records affected
throw new RecordUpdateFailedException(this, getRecordKey(rec));
}
// Correct Timestamp
if (timestampColumn != null)
{ // Set the correct Timestamp
int i = rec.getFieldIndex(timestampColumn);
if (i >= 0)
fields[i] = timestamp;
}
// Change State
rec.updateComplete(rec.getRowSetData());
}
/**
* Deletes a single record from the database.
*
* @param id the record's primary key
* @param conn a valid JDBC connection
* @return true if the record has been successfully deleted or false otherwise
*/
public final void deleteRecord(Object id, Connection conn)
{
deleteRecord(new Object[] { id }, conn);
}
/**
* Deletes all records which reference this table.
*
* @param key the key the record to be deleted
* @param conn a valid connection
* @return true if all reference records could be deleted
*/
protected final void deleteAllReferences(Object[] key, Connection conn)
{
// Merge Sub-Records
List relations = db.getRelations();
DBColumn[] keyColumns = getKeyColumns();
if (keyColumns==null)
return; // No primary key - no references!
// Find all relations
for (DBRelation rel : relations)
{ // Check cascade
if (rel.getOnDeleteAction()!=DBCascadeAction.CASCADE_RECORDS)
continue;
// References
DBReference[] refs = rel.getReferences();
for (int i=0; i
* @param refs the reference columns belonging to the relation
* @param parentKey the key of the parent element
* @param conn a valid connection
* @return true if all records could be deleted or false otherwise
*/
protected void deleteReferenceRecords(DBReference[] refs, Object[] parentKey, Connection conn)
{
// Key length and reference length must match
if (refs.length!=parentKey.length)
throw new InvalidArgumentException("refs", refs);
// Rowset
DBColumn[] keyColumns = getKeyColumns();
if (keyColumns==null || keyColumns.length==0)
{ // No Primary Key
DBCommand cmd = db.createCommand();
for (int i=0; i recKeys = db.queryObjectList(cmd, conn);
for (Object[] recKey : recKeys)
{
log.info("Deleting Record " + StringUtils.valueOf(recKey) + " from table " + getName());
deleteRecord(recKey, conn);
}
}
// Done
}
}