com.ziclix.python.sql.DataHandler Maven / Gradle / Ivy
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/*
* Jython Database Specification API 2.0
*
*
* Copyright (c) 2001 brian zimmer
*
*/
package com.ziclix.python.sql;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.lang.reflect.Constructor;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.sql.Blob;
import java.sql.CallableStatement;
import java.sql.Clob;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Time;
import java.sql.Timestamp;
import java.sql.Types;
import org.python.core.Py;
import org.python.core.PyFile;
import org.python.core.PyList;
import org.python.core.PyObject;
/**
* The DataHandler is responsible mapping the JDBC data type to
* a Jython object. Depending on the version of the JDBC
* implementation and the particulars of the driver, the type
* mapping can be significantly different.
*
* This interface can also be used to change the behaviour of
* the default mappings provided by the cursor. This might be
* useful in handling more complicated data types such as BLOBs,
* CLOBs and Arrays.
*
* @author brian zimmer
*/
public class DataHandler {
/** Default size for buffers. */
private static final int INITIAL_SIZE = 1024 * 4;
private static final String[] SYSTEM_DATAHANDLERS = {
"com.ziclix.python.sql.JDBC20DataHandler"
};
/**
* Handle most generic Java data types.
*/
public DataHandler() {}
/**
* Some database vendors are case sensitive on calls to DatabaseMetaData,
* most notably Oracle. This callback allows a DataHandler to affect the
* name.
*/
public String getMetaDataName(PyObject name) {
return ((name == Py.None) ? null : name.__str__().toString());
}
/**
* A factory method for determing the correct procedure class to use
* per the cursor type.
* @param cursor an open cursor
* @param name the name of the procedure to invoke
* @return an instance of a Procedure
* @throws SQLException
*/
public Procedure getProcedure(PyCursor cursor, PyObject name) throws SQLException {
return new Procedure(cursor, name);
}
/**
* Returns the row id of the last executed statement.
*
* @param stmt the current statement
* @return the row id of the last executed statement or None
* @throws SQLException thrown if an exception occurs
*
*/
public PyObject getRowId(Statement stmt) throws SQLException {
return Py.None;
}
/**
* A callback prior to each execution of the statement. If the statement is
* a PreparedStatement, all the parameters will have been set.
*/
public void preExecute(Statement stmt) throws SQLException {
return;
}
/**
* A callback after successfully executing the statement.
*/
public void postExecute(Statement stmt) throws SQLException {
return;
}
/**
* Any .execute() which uses prepared statements will receive a callback for deciding
* how to map the PyObject to the appropriate JDBC type.
*
* @param stmt the current PreparedStatement
* @param index the index for which this object is bound
* @param object the PyObject in question
* @throws SQLException
*/
public void setJDBCObject(PreparedStatement stmt, int index, PyObject object) throws SQLException {
try {
Object o = object.__tojava__(Object.class);
if (o instanceof BigInteger) {
//XXX: This is in here to specifically fix passing a PyLong into Postgresql.
stmt.setObject(index, o, Types.BIGINT);
} else {
stmt.setObject(index, o);
}
} catch (Exception e) {
SQLException cause = null, ex = new SQLException("error setting index [" + index + "]");
if (e instanceof SQLException) {
cause = (SQLException) e;
} else {
cause = new SQLException(e.getMessage());
}
ex.setNextException(cause);
throw ex;
}
}
/**
* Any .execute() which uses prepared statements will receive a callback for deciding
* how to map the PyObject to the appropriate JDBC type. The type is the JDBC
* type as obtained from java.sql.Types.
*
* @param stmt the current PreparedStatement
* @param index the index for which this object is bound
* @param object the PyObject in question
* @param type the java.sql.Types for which this PyObject should be bound
* @throws SQLException
*/
public void setJDBCObject(PreparedStatement stmt, int index, PyObject object, int type)
throws SQLException {
try {
if (checkNull(stmt, index, object, type)) {
return;
}
switch (type) {
case Types.DATE:
Date date = (Date) object.__tojava__(Date.class);
stmt.setDate(index, date);
break;
case Types.TIME:
Time time = (Time) object.__tojava__(Time.class);
stmt.setTime(index, time);
break;
case Types.TIMESTAMP:
Timestamp timestamp = (Timestamp) object.__tojava__(Timestamp.class);
stmt.setTimestamp(index, timestamp);
break;
case Types.LONGVARCHAR:
if (object instanceof PyFile) {
object = ((PyFile) object).read();
}
String varchar = (String) object.__tojava__(String.class);
Reader reader = new BufferedReader(new StringReader(varchar));
stmt.setCharacterStream(index, reader, varchar.length());
break;
case Types.BIT:
stmt.setBoolean(index, object.__nonzero__());
break;
default :
if (object instanceof PyFile) {
object = ((PyFile) object).read();
}
stmt.setObject(index, object.__tojava__(Object.class), type);
break;
}
} catch (Exception e) {
SQLException cause = null, ex = new SQLException("error setting index [" + index
+ "], type [" + type + "]");
if (e instanceof SQLException) {
cause = (SQLException) e;
} else {
cause = new SQLException(e.getMessage());
}
ex.setNextException(cause);
throw ex;
}
}
/**
* Given a ResultSet, column and type, return the appropriate
* Jython object.
*
* Note: DO NOT iterate the ResultSet.
*
* @param set the current ResultSet set to the current row
* @param col the column number (adjusted properly for JDBC)
* @param type the column type
* @throws SQLException if the type is unmappable
*/
public PyObject getPyObject(ResultSet set, int col, int type) throws SQLException {
PyObject obj = Py.None;
switch (type) {
case Types.CHAR:
case Types.VARCHAR:
case Types.NCHAR:
case Types.NVARCHAR:
String string = set.getString(col);
obj = string == null ? Py.None : Py.newUnicode(string);
break;
case Types.LONGVARCHAR:
case Types.LONGNVARCHAR:
Reader reader = set.getCharacterStream(col);
obj = reader == null ? Py.None : Py.newUnicode(read(reader));
break;
case Types.NUMERIC:
case Types.DECIMAL:
BigDecimal bd = set.getBigDecimal(col);
obj = (bd == null) ? Py.None : Py.newFloat(bd.doubleValue());
break;
case Types.BIT:
case Types.BOOLEAN:
obj = set.getBoolean(col) ? Py.True : Py.False;
break;
case Types.INTEGER:
case Types.TINYINT:
case Types.SMALLINT:
obj = Py.newInteger(set.getInt(col));
break;
case Types.BIGINT:
obj = Py.newLong(set.getLong(col));
break;
case Types.FLOAT:
case Types.REAL:
obj = Py.newFloat(set.getFloat(col));
break;
case Types.DOUBLE:
obj = Py.newFloat(set.getDouble(col));
break;
case Types.TIME:
obj = Py.newTime(set.getTime(col));
break;
case Types.TIMESTAMP:
obj = Py.newDatetime(set.getTimestamp(col));
break;
case Types.DATE:
Object date = set.getObject(col);
// don't newDate mysql YEAR columns
obj = date instanceof Date ? Py.newDate((Date)date) : Py.java2py(date);
break;
case Types.NULL:
obj = Py.None;
break;
case Types.OTHER:
case Types.JAVA_OBJECT:
obj = Py.java2py(set.getObject(col));
break;
case Types.BINARY:
case Types.VARBINARY:
case Types.LONGVARBINARY:
obj = Py.java2py(set.getBytes(col));
break;
case Types.BLOB:
Blob blob = set.getBlob(col);
obj = blob == null ? Py.None : Py.java2py(read(blob.getBinaryStream()));
break;
case Types.CLOB:
case Types.NCLOB:
case Types.SQLXML:
Clob clob = set.getClob(col);
obj = clob == null ? Py.None : Py.java2py(read(clob.getCharacterStream()));
break;
// TODO can we support these?
case Types.ARRAY:
throw createUnsupportedTypeSQLException("ARRAY", col);
case Types.DATALINK:
throw createUnsupportedTypeSQLException("DATALINK", col);
case Types.DISTINCT:
throw createUnsupportedTypeSQLException("DISTINCT", col);
case Types.REF:
throw createUnsupportedTypeSQLException("REF", col);
case Types.ROWID:
throw createUnsupportedTypeSQLException("STRUCT", col);
case Types.STRUCT:
throw createUnsupportedTypeSQLException("STRUCT", col);
default :
throw createUnsupportedTypeSQLException(Integer.valueOf(type), col);
}
return set.wasNull() || obj == null ? Py.None : obj;
}
protected final SQLException createUnsupportedTypeSQLException(Object type, int col) {
Object[] vals = {type, Integer.valueOf(col)};
String msg = zxJDBC.getString("unsupportedTypeForColumn", vals);
return new SQLException(msg);
}
/**
* Given a CallableStatement, column and type, return the appropriate
* Jython object.
*
* @param stmt the CallableStatement
* @param col the column number (adjusted properly for JDBC)
* @param type the column type
* @throws SQLException if the type is unmappable
*/
public PyObject getPyObject(CallableStatement stmt, int col, int type) throws SQLException {
PyObject obj = Py.None;
switch (type) {
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR:
String string = stmt.getString(col);
obj = (string == null) ? Py.None : Py.newUnicode(string);
break;
case Types.NUMERIC:
case Types.DECIMAL:
BigDecimal bd = stmt.getBigDecimal(col);
obj = (bd == null) ? Py.None : Py.newFloat(bd.doubleValue());
break;
case Types.BIT:
obj = stmt.getBoolean(col) ? Py.True : Py.False;
break;
case Types.INTEGER:
case Types.TINYINT:
case Types.SMALLINT:
obj = Py.newInteger(stmt.getInt(col));
break;
case Types.BIGINT:
obj = Py.newLong(stmt.getLong(col));
break;
case Types.FLOAT:
case Types.REAL:
obj = Py.newFloat(stmt.getFloat(col));
break;
case Types.DOUBLE:
obj = Py.newFloat(stmt.getDouble(col));
break;
case Types.TIME:
obj = Py.newTime(stmt.getTime(col));
break;
case Types.TIMESTAMP:
obj = Py.newDatetime(stmt.getTimestamp(col));
break;
case Types.DATE:
obj = Py.newDate(stmt.getDate(col));
break;
case Types.NULL:
obj = Py.None;
break;
case Types.OTHER:
obj = Py.java2py(stmt.getObject(col));
break;
case Types.BINARY:
case Types.VARBINARY:
case Types.LONGVARBINARY:
obj = Py.java2py(stmt.getBytes(col));
break;
default :
createUnsupportedTypeSQLException(type, col);
}
return stmt.wasNull() || obj == null ? Py.None : obj;
}
/**
* Called when a stored procedure or function is executed and OUT parameters
* need to be registered with the statement.
*
* @param statement
* @param index the JDBC offset column number
* @param colType the column as from DatabaseMetaData (eg, procedureColumnOut)
* @param dataType the JDBC datatype from Types
* @param dataTypeName the JDBC datatype name
*
* @throws SQLException
*
*/
public void registerOut(CallableStatement statement, int index, int colType, int dataType,
String dataTypeName) throws SQLException {
try {
statement.registerOutParameter(index, dataType);
} catch (Throwable t) {
SQLException cause = null;
SQLException ex = new SQLException("error setting index ["
+ index + "], coltype [" + colType + "], datatype [" + dataType
+ "], datatypename [" + dataTypeName + "]");
if (t instanceof SQLException) {
cause = (SQLException)t;
} else {
cause = new SQLException(t.getMessage());
}
ex.setNextException(cause);
throw ex;
}
}
/**
* Handles checking if the object is null or None and setting it on the statement.
*
* @return true if the object is null and was set on the statement, false otherwise
*/
public static final boolean checkNull(PreparedStatement stmt, int index, PyObject object,
int type) throws SQLException {
if ((object == null) || (Py.None == object)) {
stmt.setNull(index, type);
return true;
}
return false;
}
/**
* Consume the InputStream into an byte array and close the InputStream.
*
* @return the contents of the InputStream a byte[]
*/
public static final byte[] read(InputStream stream) {
int size = 0;
byte[] buffer = new byte[INITIAL_SIZE];
ByteArrayOutputStream baos = new ByteArrayOutputStream(INITIAL_SIZE);
try {
while ((size = stream.read(buffer)) != -1) {
baos.write(buffer, 0, size);
}
} catch (IOException ioe) {
throw zxJDBC.makeException(ioe);
} finally {
try {
stream.close();
} catch (IOException ioe) {
throw zxJDBC.makeException(ioe);
}
}
return baos.toByteArray();
}
/**
* Consume the Reader into a String and close the Reader.
*
* @return the contents of the Reader as a String
*/
public static String read(Reader reader) {
int size = 0;
char[] buffer = new char[INITIAL_SIZE];
StringBuilder builder = new StringBuilder(INITIAL_SIZE);
try {
while ((size = reader.read(buffer)) != -1) {
builder.append(buffer, 0, size);
}
} catch (IOException ioe) {
throw zxJDBC.makeException(ioe);
} finally {
try {
reader.close();
} catch (IOException ioe) {
throw zxJDBC.makeException(ioe);
}
}
return builder.toString();
}
/**
* Build the DataHandler chain depending on the VM. This guarentees a DataHandler
* but might additionally chain a JDBC2.0 or JDBC3.0 implementation.
* @return a DataHandler configured for the VM version
*/
public static final DataHandler getSystemDataHandler() {
DataHandler dh = new DataHandler();
for (String element : SYSTEM_DATAHANDLERS) {
try {
Class c = Class.forName(element);
Constructor cons = c.getConstructor(new Class[]{DataHandler.class});
dh = (DataHandler) cons.newInstance(new Object[]{dh});
} catch (Throwable t) {}
}
return dh;
}
/**
* Returns a list of datahandlers chained together through the use of delegation.
*
* @return a list of datahandlers
*/
public PyObject __chain__() {
return new PyList(Py.javas2pys(this));
}
/**
* Returns the classname of this datahandler.
*/
@Override
public String toString() {
return getClass().getName();
}
}