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/*
* 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.commons.dbutils;
import static java.sql.DriverManager.registerDriver;
import java.io.PrintWriter;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverPropertyInfo;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.sql.Statement;
import java.util.logging.Logger;
import java.util.Properties;
/**
* A collection of JDBC helper methods. This class is thread safe.
*/
public final class DbUtils {
/**
* Default constructor.
*
* Utility classes should not have a public or default constructor,
* but this one preserves retro-compatibility.
*
* @since 1.4
*/
public DbUtils() {
// do nothing
}
/**
* Close a Connection, avoid closing if null.
*
* @param conn Connection to close.
* @throws SQLException if a database access error occurs
*/
public static void close(Connection conn) throws SQLException {
if (conn != null) {
conn.close();
}
}
/**
* Close a ResultSet, avoid closing if null.
*
* @param rs ResultSet to close.
* @throws SQLException if a database access error occurs
*/
public static void close(ResultSet rs) throws SQLException {
if (rs != null) {
rs.close();
}
}
/**
* Close a Statement, avoid closing if null.
*
* @param stmt Statement to close.
* @throws SQLException if a database access error occurs
*/
public static void close(Statement stmt) throws SQLException {
if (stmt != null) {
stmt.close();
}
}
/**
* Close a Connection, avoid closing if null and hide
* any SQLExceptions that occur.
*
* @param conn Connection to close.
*/
public static void closeQuietly(Connection conn) {
try {
close(conn);
} catch (SQLException e) { // NOPMD
// quiet
}
}
/**
* Close a Connection, Statement and
* ResultSet. Avoid closing if null and hide any
* SQLExceptions that occur.
*
* @param conn Connection to close.
* @param stmt Statement to close.
* @param rs ResultSet to close.
*/
public static void closeQuietly(Connection conn, Statement stmt,
ResultSet rs) {
try {
closeQuietly(rs);
} finally {
try {
closeQuietly(stmt);
} finally {
closeQuietly(conn);
}
}
}
/**
* Close a ResultSet, avoid closing if null and hide any
* SQLExceptions that occur.
*
* @param rs ResultSet to close.
*/
public static void closeQuietly(ResultSet rs) {
try {
close(rs);
} catch (SQLException e) { // NOPMD
// quiet
}
}
/**
* Close a Statement, avoid closing if null and hide
* any SQLExceptions that occur.
*
* @param stmt Statement to close.
*/
public static void closeQuietly(Statement stmt) {
try {
close(stmt);
} catch (SQLException e) { // NOPMD
// quiet
}
}
/**
* Commits a Connection then closes it, avoid closing if null.
*
* @param conn Connection to close.
* @throws SQLException if a database access error occurs
*/
public static void commitAndClose(Connection conn) throws SQLException {
if (conn != null) {
try {
conn.commit();
} finally {
conn.close();
}
}
}
/**
* Commits a Connection then closes it, avoid closing if null
* and hide any SQLExceptions that occur.
*
* @param conn Connection to close.
*/
public static void commitAndCloseQuietly(Connection conn) {
try {
commitAndClose(conn);
} catch (SQLException e) { // NOPMD
// quiet
}
}
/**
* Loads and registers a database driver class.
* If this succeeds, it returns true, else it returns false.
*
* @param driverClassName of driver to load
* @return boolean true if the driver was found, otherwise false
*/
public static boolean loadDriver(String driverClassName) {
return loadDriver(DbUtils.class.getClassLoader(), driverClassName);
}
/**
* Loads and registers a database driver class.
* If this succeeds, it returns true, else it returns false.
*
* @param classLoader the class loader used to load the driver class
* @param driverClassName of driver to load
* @return boolean true if the driver was found, otherwise false
* @since 1.4
*/
public static boolean loadDriver(ClassLoader classLoader, String driverClassName) {
try {
Class loadedClass = classLoader.loadClass(driverClassName);
if (!Driver.class.isAssignableFrom(loadedClass)) {
return false;
}
@SuppressWarnings("unchecked") // guarded by previous check
Class driverClass = (Class) loadedClass;
Constructor driverConstructor = driverClass.getConstructor();
// make Constructor accessible if it is private
boolean isConstructorAccessible = driverConstructor.isAccessible();
if (!isConstructorAccessible) {
driverConstructor.setAccessible(true);
}
try {
Driver driver = driverConstructor.newInstance();
registerDriver(new DriverProxy(driver));
} finally {
driverConstructor.setAccessible(isConstructorAccessible);
}
return true;
} catch (RuntimeException e) {
return false;
} catch (Exception e) {
return false;
}
}
/**
* Print the stack trace for a SQLException to STDERR.
*
* @param e SQLException to print stack trace of
*/
public static void printStackTrace(SQLException e) {
printStackTrace(e, new PrintWriter(System.err));
}
/**
* Print the stack trace for a SQLException to a
* specified PrintWriter.
*
* @param e SQLException to print stack trace of
* @param pw PrintWriter to print to
*/
public static void printStackTrace(SQLException e, PrintWriter pw) {
SQLException next = e;
while (next != null) {
next.printStackTrace(pw);
next = next.getNextException();
if (next != null) {
pw.println("Next SQLException:");
}
}
}
/**
* Print warnings on a Connection to STDERR.
*
* @param conn Connection to print warnings from
*/
public static void printWarnings(Connection conn) {
printWarnings(conn, new PrintWriter(System.err));
}
/**
* Print warnings on a Connection to a specified PrintWriter.
*
* @param conn Connection to print warnings from
* @param pw PrintWriter to print to
*/
public static void printWarnings(Connection conn, PrintWriter pw) {
if (conn != null) {
try {
printStackTrace(conn.getWarnings(), pw);
} catch (SQLException e) {
printStackTrace(e, pw);
}
}
}
/**
* Rollback any changes made on the given connection.
* @param conn Connection to rollback. A null value is legal.
* @throws SQLException if a database access error occurs
*/
public static void rollback(Connection conn) throws SQLException {
if (conn != null) {
conn.rollback();
}
}
/**
* Performs a rollback on the Connection then closes it,
* avoid closing if null.
*
* @param conn Connection to rollback. A null value is legal.
* @throws SQLException if a database access error occurs
* @since DbUtils 1.1
*/
public static void rollbackAndClose(Connection conn) throws SQLException {
if (conn != null) {
try {
conn.rollback();
} finally {
conn.close();
}
}
}
/**
* Performs a rollback on the Connection then closes it,
* avoid closing if null and hide any SQLExceptions that occur.
*
* @param conn Connection to rollback. A null value is legal.
* @since DbUtils 1.1
*/
public static void rollbackAndCloseQuietly(Connection conn) {
try {
rollbackAndClose(conn);
} catch (SQLException e) { // NOPMD
// quiet
}
}
/**
* Simple {@link Driver} proxy class that proxies a JDBC Driver loaded dynamically.
*
* @since 1.6
*/
private static final class DriverProxy implements Driver {
private boolean parentLoggerSupported = true;
/**
* The adapted JDBC Driver loaded dynamically.
*/
private final Driver adapted;
/**
* Creates a new JDBC Driver that adapts a JDBC Driver loaded dynamically.
*
* @param adapted the adapted JDBC Driver loaded dynamically.
*/
public DriverProxy(Driver adapted) {
this.adapted = adapted;
}
/**
* {@inheritDoc}
*/
@Override
public boolean acceptsURL(String url) throws SQLException {
return adapted.acceptsURL(url);
}
/**
* {@inheritDoc}
*/
@Override
public Connection connect(String url, Properties info) throws SQLException {
return adapted.connect(url, info);
}
/**
* {@inheritDoc}
*/
@Override
public int getMajorVersion() {
return adapted.getMajorVersion();
}
/**
* {@inheritDoc}
*/
@Override
public int getMinorVersion() {
return adapted.getMinorVersion();
}
/**
* {@inheritDoc}
*/
@Override
public DriverPropertyInfo[] getPropertyInfo(String url, Properties info) throws SQLException {
return adapted.getPropertyInfo(url, info);
}
/**
* {@inheritDoc}
*/
@Override
public boolean jdbcCompliant() {
return adapted.jdbcCompliant();
}
/**
* Java 1.7 method.
*/
public Logger getParentLogger() throws SQLFeatureNotSupportedException {
if (parentLoggerSupported) {
try {
Method method = adapted.getClass().getMethod("getParentLogger", new Class[0]);
return (Logger)method.invoke(adapted, new Object[0]);
} catch (NoSuchMethodException e) {
parentLoggerSupported = false;
throw new SQLFeatureNotSupportedException(e);
} catch (IllegalAccessException e) {
parentLoggerSupported = false;
throw new SQLFeatureNotSupportedException(e);
} catch (InvocationTargetException e) {
parentLoggerSupported = false;
throw new SQLFeatureNotSupportedException(e);
}
}
throw new SQLFeatureNotSupportedException();
}
}
}