package umontreal.iro.lecuyer.util;
import java.io.*;
import java.net.URL;
import java.sql.*;
import javax.sql.DataSource;
import java.util.Properties;
import javax.naming.*;
/**
* This class provides some facilities to connect to a SQL database and to
* retrieve data stored in it.
* JDBC provides a standardized interface for accessing a database
* independently of a specific database management system (DBMS).
* The user of JDBC must create a {@link Connection} object
* used to send SQL queries to the underlying DBMS, but
* the creation of the connection adds a DBMS-specific portion
* in the application.
* This class helps the developer in moving the DBMS-specific
* information out of the source code by storing it in
* a properties file. The methods in this class can
* read such a properties file and establish the JDBC connection.
* The connection can be made by using a {@link DataSource} obtained
* through a JNDI server, or by a JDBC URI associated with a
* driver class.
* Therefore, the properties used to connect to the
* database must be a JNDI name (jdbc.jndi-name),
* or a driver to load
* (jdbc.driver) with the URI of a database (jdbc.uri).
*
*
*
*
*
jdbc.driver=com.mysql.jdbc.Driver
*
*
jdbc.uri=jdbc:mysql://mysql.iro.umontreal.ca/database?user=foo&password=bar
*
*
*
*
* The connection is established using the
* {@link #connectToDatabase((Properties)) connectToDatabase}
* method. Shortcut methods are also available to read the
* properties from a file or a resource before establishing the connection.
* This class also provides shortcut methods to read data from a database
* and to copy the data into Java arrays.
*
*/
public class JDBCManager {
/**
* Connects to the database using the properties prop and returns the
* an object representing the connection.
* The properties stored in prop must be a JNDI name
* (jdbc.jndi-name), or the name of a driver
* (jdbc.driver) to load and the URI of the database (jdbc.uri).
* When a JNDI name is given, this method constructs a
* context using the nullary constructor of {@link InitialContext},
* uses the context to get a {@link DataSource} object,
* and uses the data source to obtain a connection.
* This method assumes that JNDI is configured correctly;
* see the class {@link InitialContext} for more information about configuring
* JNDI.
* If no JNDI name is specified, the method looks for a JDBC URI.
* If a driver class name is specified along with the URI, the corresponding driver
* is loaded and registered with the JDBC {@link DriverManager}.
* The driver manager is then used to obtain the connection using the URI.
* This method throws
* an {@link SQLException} if the connection failed and an
* {@link IllegalArgumentException}
* if the properties do not contain the required values.
*
* @param prop the properties to connect to the database.
*
* @return the connection to the database.
* @exception SQLException if the connection failed.
*
* @exception IllegalArgumentException if the properties do not contain the require values.
*
*
*/
public static Connection connectToDatabase (Properties prop)
throws SQLException {
Connection connection = null;
String jndiName;
if ((jndiName = prop.getProperty ("jdbc.jndi-name")) != null)
{
try
{
InitialContext context = new InitialContext();
connection = ((DataSource) context.lookup (jndiName)).getConnection();
}
catch (NamingException e)
{
throw new IllegalArgumentException
("The jdbc.jndi-name property refers to the invalid name " + jndiName);
}
}
else
{
String driver = prop.getProperty ("jdbc.driver");
String uri = prop.getProperty ("jdbc.uri");
if (uri != null)
{
if (driver != null) {
try
{
Class driverClass = Class.forName (driver);
if (!Driver.class.isAssignableFrom (driverClass))
throw new IllegalArgumentException
("The driver name " + driver +
" does not correspond to a class implementing the java.sql.Driver interface");
// Needed by some buggy drivers
driverClass.newInstance();
}
catch (ClassNotFoundException cnfe) {
throw new IllegalArgumentException ("Could not find the driver class " + driver);
}
catch (IllegalAccessException iae) {
throw new IllegalArgumentException
("An illegal access prevented the instantiation of driver class " + driver);
}
catch (InstantiationException ie) {
throw new IllegalArgumentException
("An instantiation exception prevented the instantiation of driver class " + driver +
": " + ie.getMessage());
}
}
connection = DriverManager.getConnection (uri);
}
else
{
throw new IllegalArgumentException
("The jdbc.driver and jdbc.uri properties must be given if jdbc.jndi-name is not set");
}
}
return connection;
}
/**
* Returns a connection to the database using the properties read from stream is.
* This method loads the properties from the given stream, and
* calls {@link #connectToDatabase((Properties)) connectToDatabase} to establish the connection.
*
* @param is the stream to read for the properties.
*
* @return the connection to the database.
* @exception SQLException if the connection failed.
*
* @exception IOException if the stream can not be read correctly.
*
* @exception IllegalArgumentException if the properties do not contain the require values.
*
*
*/
public static Connection connectToDatabase (InputStream is)
throws IOException, SQLException {
Properties prop = new Properties();
prop.load (is);
return connectToDatabase (prop);
}
/**
* Equivalent to {@link #connectToDatabase((InputStream)) connectToDatabase} (url.openStream()).
*
*/
public static Connection connectToDatabase (URL url)
throws IOException, SQLException {
InputStream is = url.openStream();
try {
return connectToDatabase (is);
}
finally {
is.close();
}
}
/**
* Equivalent to {@link #connectToDatabase((InputStream)) connectToDatabase} (new FileInputStream (file)).
*
*/
public static Connection connectToDatabase (File file)
throws IOException, SQLException {
FileInputStream is = new FileInputStream (file);
try {
return connectToDatabase (is);
}
finally {
is.close();
}
}
/**
* Equivalent to {@link #connectToDatabase((InputStream)) connectToDatabase} (new FileInputStream (fileName)).
*
*/
public static Connection connectToDatabase (String fileName)
throws IOException, SQLException {
FileInputStream is = new FileInputStream (fileName);
try {
return connectToDatabase (is);
}
finally {
is.close();
}
}
/**
* Uses {@link #connectToDatabase((InputStream)) connectToDatabase} with the stream obtained from
* the resource resource.
* This method searches the file resource on the class path, opens
* the first resource found, and extracts properties from it.
* It then uses {@link #connectToDatabase((Properties)) connectToDatabase}
* to establish the connection.
*
*/
public static Connection connectToDatabaseFromResource (String resource)
throws IOException, SQLException {
InputStream is = JDBCManager.class.getClassLoader().getResourceAsStream (resource);
try {
return connectToDatabase (is);
}
finally {
is.close();
}
}
/**
* Copies the result of the SQL query query into an array of double-precision values.
* This method uses the statement stmt to execute the given query, and
* assumes that the first column of the result set contains double-precision values.
* Each row of the result set then becomes an element of an array of double-precision
* values which is returned by this method.
* This method throws an {@link SQLException} if the query is not valid.
*
* @param stmt the statement used to make the query.
*
* @param query the SQL query to execute.
*
* @return the first column of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static double[] readDoubleData (Statement stmt, String query)
throws SQLException {
ResultSet rs = stmt.executeQuery (query);
rs.last();
double[] res = new double[rs.getRow()];
rs.first();
for (int i = 0; i < res.length; i++)
{
res[i] = rs.getDouble (1);
rs.next();
}
rs.close();
return res;
}
/**
* Copies the result of the SQL query query into an array of double-precision values.
* This method uses the active connection connection to create
* a statement, and passes this statement, with the query, to
* {@link #readDoubleData((Statement,String)) readDoubleData}, which returns an
* array of double-precision values.
*
* @param connection the active connection to the database.
*
* @param query the SQL query to execute.
*
* @return the first column of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static double[] readDoubleData (Connection connection,
String query)
throws SQLException {
Statement stmt = connection.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
try {
return readDoubleData (stmt, query);
}
finally {
stmt.close();
}
}
/**
* Returns the values of the column column of the table table.
* This method is equivalent to {@link #readDoubleData((Statement, String)) readDoubleData}
* (stmt, "SELECT column FROM table").
*
*/
public static double[] readDoubleData (Statement stmt, String table,
String column)
throws SQLException {
final String query = "SELECT " + column + " FROM " + table;
return readDoubleData (stmt, query);
}
/**
* Returns the values of the column column of the table table.
* This method is equivalent to {@link #readDoubleData((Connection, String)) readDoubleData}
* (connection, "SELECT column FROM table").
*
*/
public static double[] readDoubleData (Connection connection,
String table, String column)
throws SQLException {
final String query = "SELECT " + column + " FROM " + table;
return readDoubleData (connection, query);
}
/**
* Copies the result of the SQL query query into an array of integers.
* This method uses the statement stmt to execute the given query, and
* assumes that the first column of the result set contains integer values.
* Each row of the result set then becomes an element of an array of integers
* which is returned by this method.
* This method throws an {@link SQLException} if the query is not valid.
* The given statement stmt must not be set up to
* produce forward-only result sets.
*
* @param stmt the statement used to make the query.
*
* @param query the SQL query to execute.
*
* @return the first column of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static int[] readIntData (Statement stmt, String query)
throws SQLException {
ResultSet rs = stmt.executeQuery (query);
rs.last();
int[] res = new int[rs.getRow()];
rs.first();
for (int i = 0; i < res.length; i++)
{
res[i] = rs.getInt (1);
rs.next();
}
rs.close();
return res;
}
/**
* Copies the result of the SQL query query into an array of integers.
* This method uses the active connection connection to create
* a statement, and passes this statement, with the query, to
* {@link #readIntData((Statement,String)) readIntData}, which returns an
* array of integers.
*
* @param connection the active connection to the database.
*
* @param query the SQL query to execute.
*
* @return the first column of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static int[] readIntData (Connection connection, String query)
throws SQLException {
Statement stmt = connection.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
try {
return readIntData (stmt, query);
}
finally {
stmt.close();
}
}
/**
* Returns the values of the column column of the table table.
* This method is equivalent to {@link #readIntData((Statement, String)) readIntData}
* (stmt, "SELECT column FROM table").
*
*/
public static int[] readIntData (Statement stmt, String table,
String column)
throws SQLException {
final String query = "SELECT " + column + " FROM " + table;
return readIntData (stmt, query);
}
/**
* Returns the values of the column column of the table table.
* This method is equivalent to {@link #readIntData((Connection, String)) readIntData}
* (connection, "SELECT column FROM table").
*
*/
public static int[] readIntData (Connection connection, String table,
String column)
throws SQLException {
final String query = "SELECT " + column + " FROM " + table;
return readIntData (connection, query);
}
/**
* Copies the result of the SQL query query into an array of objects.
* This method uses the statement stmt to execute the given query, and
* extracts values from the first column of the obtained result set by
* using the getObject method.
* Each row of the result set then becomes an element of an array of objects
* which is returned by this method.
* The type of the objects in the array depends on the column type of
* the result set, which depends on the database and query.
* This method throws an {@link SQLException} if the query is not valid.
* The given statement stmt must not be set up to
* produce forward-only result sets.
*
* @param stmt the statement used to make the query.
*
* @param query the SQL query to execute.
*
* @return the first column of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static Object[] readObjectData (Statement stmt, String query)
throws SQLException {
ResultSet rs = stmt.executeQuery (query);
rs.last();
Object[] res = new Object[rs.getRow()];
rs.first();
for (int i = 0; i < res.length; i++)
{
res[i] = rs.getObject (1);
rs.next();
}
rs.close();
return res;
}
/**
* Copies the result of the SQL query query into an array of objects.
* This method uses the active connection connection to create
* a statement, and passes this statement, with the query, to
* {@link #readObjectData((Statement,String)) readObjectData}, which returns an
* array of integers.
*
* @param connection the active connection to the database.
*
* @param query the SQL query to execute.
*
* @return the first column of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static Object[] readObjectData (Connection connection,
String query)
throws SQLException {
Statement stmt = connection.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
try {
return readObjectData (stmt, query);
}
finally {
stmt.close();
}
}
/**
* Returns the values of the column column of the table table.
* This method is equivalent to {@link #readObjectData((Statement, String)) readObjectData}
* (stmt, "SELECT column FROM table").
*
*/
public static Object[] readObjectData (Statement stmt,
String table, String column)
throws SQLException {
final String query = "SELECT " + column + " FROM " + table;
return readObjectData (stmt, query);
}
/**
* Returns the values of the column column of the table table.
* This method is equivalent to {@link #readObjectData((Connection, String)) readObjectData}
* (connection, "SELECT column FROM table").
*
*/
public static Object[] readObjectData (Connection connection,
String table, String column)
throws SQLException {
final String query = "SELECT " + column + " FROM " + table;
return readObjectData (connection, query);
}
/**
* Copies the result of the SQL query query into a
* rectangular 2D array of double-precision values.
* This method uses the statement stmt to execute the given query, and
* assumes that the columns of the result set contain double-precision values.
* Each row of the result set then becomes a row of a 2D array of double-precision
* values which is returned by this method.
* This method throws an {@link SQLException} if the query is not valid.
* The given statement stmt must not be set up to
* produce forward-only result sets.
*
* @param stmt the statement used to make the query.
*
* @param query the SQL query to execute.
*
* @return the columns of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static double[][] readDoubleData2D (Statement stmt, String query)
throws SQLException {
ResultSet rs = stmt.executeQuery (query);
rs.last();
int c = rs.getMetaData().getColumnCount();
double[][] res = new double[rs.getRow()][c];
rs.first();
for (int i = 0; i < res.length; i++) {
for (int j = 0; j < res[i].length; j++)
res[i][j] = rs.getDouble (1 + j);
rs.next();
}
rs.close();
return res;
}
/**
* Copies the result of the SQL query query into a rectangular 2D array
* of double-precision values.
* This method uses the active connection connection to create
* a statement, and passes this statement, with the query, to
* {@link #readDoubleData2D((Statement,String)) readDoubleData2D}, which returns a 2D
* array of double-precision values.
*
* @param connection the active connection to the database.
*
* @param query the SQL query to execute.
*
* @return the columns of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static double[][] readDoubleData2D (Connection connection,
String query)
throws SQLException {
Statement stmt = connection.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
try {
return readDoubleData2D (stmt, query);
}
finally {
stmt.close();
}
}
/**
* Returns the values of the columns of the table table.
* This method is equivalent to {@link #readDoubleData2D((Statement, String)) readDoubleData2D}
* (stmt, "SELECT * FROM table").
*
*/
public static double[][] readDoubleData2DTable (Statement stmt,
String table)
throws SQLException {
final String query = "SELECT * FROM " + table;
return readDoubleData2D (stmt, query);
}
/**
* Returns the values of the columns of the table table.
* This method is equivalent to {@link #readDoubleData2D((Connection, String)) readDoubleData2D}
* (connection, "SELECT * FROM table").
*
*/
public static double[][] readDoubleData2DTable (Connection connection,
String table)
throws SQLException {
final String query = "SELECT * FROM " + table;
return readDoubleData2D (connection, query);
}
/**
* Copies the result of the SQL query query into a
* rectangular 2D array of integers.
* This method uses the statement stmt to execute the given query, and
* assumes that the columns of the result set contain integers.
* Each row of the result set then becomes a row of a 2D array of integers
* which is returned by this method.
* This method throws an {@link SQLException} if the query is not valid.
* The given statement stmt must not be set up to
* produce forward-only result sets.
*
* @param stmt the statement used to make the query.
*
* @param query the SQL query to execute.
*
* @return the columns of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static int[][] readIntData2D (Statement stmt, String query)
throws SQLException {
ResultSet rs = stmt.executeQuery (query);
rs.last();
int c = rs.getMetaData().getColumnCount();
int[][] res = new int[rs.getRow()][c];
rs.first();
for (int i = 0; i < res.length; i++) {
for (int j = 0; j < res[i].length; j++)
res[i][j] = rs.getInt (1 + j);
rs.next();
}
rs.close();
return res;
}
/**
* Copies the result of the SQL query query into a rectangular 2D array
* of integers.
* This method uses the active connection connection to create
* a statement, and passes this statement, with the query, to
* {@link #readIntData2D((Statement,String)) readIntData2D}, which returns a 2D
* array of integers.
*
* @param connection the active connection to the database.
*
* @param query the SQL query to execute.
*
* @return the columns of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static int[][] readIntData2D (Connection connection, String query)
throws SQLException {
Statement stmt = connection.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
try {
return readIntData2D (stmt, query);
}
finally {
stmt.close();
}
}
/**
* Returns the values of the columns of the table table.
* This method is equivalent to {@link #readIntData2D((Statement, String)) readIntData2D}
* (stmt, "SELECT * FROM table").
*
*/
public static int[][] readIntData2DTable (Statement stmt, String table)
throws SQLException {
final String query = "SELECT * FROM " + table;
return readIntData2D (stmt, query);
}
/**
* Returns the values of the columns of the table table.
* This method is equivalent to {@link #readIntData2D((Connection, String)) readIntData2D}
* (connection, "SELECT * FROM table").
*
*/
public static int[][] readIntData2DTable (Connection connection,
String table)
throws SQLException {
final String query = "SELECT * FROM " + table;
return readIntData2D (connection, query);
}
/**
* Copies the result of the SQL query query into a
* rectangular 2D array of objects.
* This method uses the statement stmt to execute the given query, and
* extracts values from the obtained result set by using the getObject method.
* Each row of the result set then becomes a row of a 2D array of objects
* which is returned by this method.
* The type of the objects in the 2D array depends on the column types of
* the result set, which depend on the database and query.
* This method throws an {@link SQLException} if the query is not valid.
* The given statement stmt must not be set up to
* produce forward-only result sets.
*
* @param stmt the statement used to make the query.
*
* @param query the SQL query to execute.
*
* @return the columns of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static Object[][] readObjectData2D (Statement stmt, String query)
throws SQLException {
ResultSet rs = stmt.executeQuery (query);
rs.last();
int c = rs.getMetaData().getColumnCount();
Object[][] res = new Object[rs.getRow()][c];
rs.first();
for (int i = 0; i < res.length; i++) {
for (int j = 0; j < res[i].length; j++)
res[i][j] = rs.getObject (1 + j);
rs.next();
}
rs.close();
return res;
}
/**
* Copies the result of the SQL query query into a rectangular 2D array
* of integers.
* This method uses the active connection connection to create
* a statement, and passes this statement, with the query, to
* {@link #readObjectData2D((Statement,String)) readObjectData2D}, which returns a 2D
* array of integers.
*
* @param connection the active connection to the database.
*
* @param query the SQL query to execute.
*
* @return the columns of the result set.
* @exception SQLException if the query is not valid.
*
*
*/
public static Object[][] readObjectData2D (Connection connection,
String query)
throws SQLException {
Statement stmt = connection.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
try {
return readObjectData2D (stmt, query);
}
finally {
stmt.close();
}
}
/**
* Returns the values of the columns of the table table.
* This method is equivalent to {@link #readObjectData2D((Statement, String)) readObjectData2D}
* (stmt, "SELECT * FROM table").
*
*/
public static Object[][] readObjectData2DTable (Statement stmt,
String table)
throws SQLException {
final String query = "SELECT * FROM " + table;
return readObjectData2D (stmt, query);
}
/**
* Returns the values of the columns of the table table.
* This method is equivalent to {@link #readObjectData2D((Connection, String)) readObjectData2D}
* (connection, "SELECT * FROM table").
*
*/
public static Object[][] readObjectData2DTable (Connection connection,
String table)
throws SQLException {
final String query = "SELECT * FROM " + table;
return readObjectData2D (connection, query);
}
}
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