/*
* 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.skfiy.typhon.rnsd.util;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
* 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
*/
private DbUtils() {
// do nothing
}
/**
* Close a <code>Connection</code>, 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 <code>ResultSet</code>, 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 <code>Statement</code>, 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 <code>Connection</code>, 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 <code>Connection</code> and <code>Statement</code>. Avoid closing if null and hide
* any SQLExceptions that occur.
*
* @param conn Connection to close.
* @param stmt Statement to close.
*/
public static void closeQuietly(Connection conn, Statement stmt) {
closeQuietly(stmt);
closeQuietly(conn);
}
/**
* Close a <code>Connection</code>, <code>Statement</code> and <code>ResultSet</code>. 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) {
closeQuietly(rs);
closeQuietly(stmt);
closeQuietly(conn);
}
/**
* Close a <code>ResultSet</code>, 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 <code>Statement</code>, 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 <code>Connection</code> 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 <code>Connection</code>.
*
* @param conn Connection to commit.
*/
public static void commitAndCloseQuietly(Connection conn) {
try {
commitAndClose(conn);
} catch (SQLException e) { // NOPMD
// quiet
}
}
/**
* Commits a <code>Connection</code> then closes it, avoid closing if null and hide any
* SQLExceptions that occur.
*
* @param conn Connection to close.
*/
public static void commitQuietly(Connection conn) {
try {
conn.commit();
} 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 <code>true</code> if the driver was found, otherwise <code>false</code>
*/
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 <code>true</code> if the driver was found, otherwise <code>false</code>
* @since 1.4
*/
public static boolean loadDriver(ClassLoader classLoader, String driverClassName) {
try {
classLoader.loadClass(driverClassName).newInstance();
return true;
} catch (IllegalAccessException e) {
// Constructor is private, OK for DriverManager contract
return true;
} 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 <code>Connection</code> 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 <code>Connection</code> 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
}
}
/**
* Performs a rollback on the <code>Connection</code>.
*
* @param conn Connection to rollback. A null value is legal.
*/
public static void rollbackQuietly(Connection conn) {
try {
rollback(conn);
} catch (SQLException ex) { // NOPMD
// quiet
}
}
}