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Tomcat example source code file (JDBCRealm.java)

This example Tomcat source code file (JDBCRealm.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

arraylist, driver, jdbc, preparedstatement, preparedstatement, principal, principal, properties, security, sql, sqlexception, sqlexception, string, string, stringbuffer, throwable, util, where

The Tomcat JDBCRealm.java source code

/*
 * 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.catalina.realm;


import java.security.Principal;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Properties;

import org.apache.catalina.LifecycleException;
import org.apache.catalina.util.StringManager;


/**
*
* Implmentation of <b>Realm that works with any JDBC supported database.
* See the JDBCRealm.howto for more details on how to set up the database and
* for configuration options.
*
* <p>TODO - Support connection pooling (including message
* format objects) so that <code>authenticate(),
* <code>getPassword() and authenticate() do not have to be
* synchronized and would fix the ugly connection logic. </p>
*
* @author Craig R. McClanahan
* @author Carson McDonald
* @author Ignacio Ortega
* @version $Revision: 543691 $ $Date: 2007-06-02 03:37:08 +0200 (sam., 02 juin 2007) $
*/

public class JDBCRealm
    extends RealmBase {


    // ----------------------------------------------------- Instance Variables


    /**
     * The connection username to use when trying to connect to the database.
     */
    protected String connectionName = null;


    /**
     * The connection URL to use when trying to connect to the database.
     */
    protected String connectionPassword = null;


    /**
     * The connection URL to use when trying to connect to the database.
     */
    protected String connectionURL = null;


    /**
     * The connection to the database.
     */
    protected Connection dbConnection = null;


    /**
     * Instance of the JDBC Driver class we use as a connection factory.
     */
    protected Driver driver = null;


    /**
     * The JDBC driver to use.
     */
    protected String driverName = null;


    /**
     * Descriptive information about this Realm implementation.
     */
    protected static final String info =
        "org.apache.catalina.realm.JDBCRealm/1.0";


    /**
     * Descriptive information about this Realm implementation.
     */
    protected static final String name = "JDBCRealm";


    /**
     * The PreparedStatement to use for authenticating users.
     */
    protected PreparedStatement preparedCredentials = null;


    /**
     * The PreparedStatement to use for identifying the roles for
     * a specified user.
     */
    protected PreparedStatement preparedRoles = null;


    /**
     * The column in the user role table that names a role
     */
    protected String roleNameCol = null;


    /**
     * The string manager for this package.
     */
    protected static final StringManager sm =
        StringManager.getManager(Constants.Package);


    /**
     * The column in the user table that holds the user's credintials
     */
    protected String userCredCol = null;


    /**
     * The column in the user table that holds the user's name
     */
    protected String userNameCol = null;


    /**
     * The table that holds the relation between user's and roles
     */
    protected String userRoleTable = null;


    /**
     * The table that holds user data.
     */
    protected String userTable = null;


    // ------------------------------------------------------------- Properties

    /**
     * Return the username to use to connect to the database.
     *
     */
    public String getConnectionName() {
        return connectionName;
    }

    /**
     * Set the username to use to connect to the database.
     *
     * @param connectionName Username
     */
    public void setConnectionName(String connectionName) {
        this.connectionName = connectionName;
    }

    /**
     * Return the password to use to connect to the database.
     *
     */
    public String getConnectionPassword() {
        return connectionPassword;
    }

    /**
     * Set the password to use to connect to the database.
     *
     * @param connectionPassword User password
     */
    public void setConnectionPassword(String connectionPassword) {
        this.connectionPassword = connectionPassword;
    }

    /**
     * Return the URL to use to connect to the database.
     *
     */
    public String getConnectionURL() {
        return connectionURL;
    }

    /**
     * Set the URL to use to connect to the database.
     *
     * @param connectionURL The new connection URL
     */
    public void setConnectionURL( String connectionURL ) {
      this.connectionURL = connectionURL;
    }

    /**
     * Return the JDBC driver that will be used.
     *
     */
    public String getDriverName() {
        return driverName;
    }

    /**
     * Set the JDBC driver that will be used.
     *
     * @param driverName The driver name
     */
    public void setDriverName( String driverName ) {
      this.driverName = driverName;
    }

    /**
     * Return the column in the user role table that names a role.
     *
     */
    public String getRoleNameCol() {
        return roleNameCol;
    }

    /**
     * Set the column in the user role table that names a role.
     *
     * @param roleNameCol The column name
     */
    public void setRoleNameCol( String roleNameCol ) {
        this.roleNameCol = roleNameCol;
    }

    /**
     * Return the column in the user table that holds the user's credentials.
     *
     */
    public String getUserCredCol() {
        return userCredCol;
    }

    /**
     * Set the column in the user table that holds the user's credentials.
     *
     * @param userCredCol The column name
     */
    public void setUserCredCol( String userCredCol ) {
       this.userCredCol = userCredCol;
    }

    /**
     * Return the column in the user table that holds the user's name.
     *
     */
    public String getUserNameCol() {
        return userNameCol;
    }

    /**
     * Set the column in the user table that holds the user's name.
     *
     * @param userNameCol The column name
     */
    public void setUserNameCol( String userNameCol ) {
       this.userNameCol = userNameCol;
    }

    /**
     * Return the table that holds the relation between user's and roles.
     *
     */
    public String getUserRoleTable() {
        return userRoleTable;
    }

    /**
     * Set the table that holds the relation between user's and roles.
     *
     * @param userRoleTable The table name
     */
    public void setUserRoleTable( String userRoleTable ) {
        this.userRoleTable = userRoleTable;
    }

    /**
     * Return the table that holds user data..
     *
     */
    public String getUserTable() {
        return userTable;
    }

    /**
     * Set the table that holds user data.
     *
     * @param userTable The table name
     */
    public void setUserTable( String userTable ) {
      this.userTable = userTable;
    }


    // --------------------------------------------------------- Public Methods


    /**
     * Return the Principal associated with the specified username and
     * credentials, if there is one; otherwise return <code>null.
     *
     * If there are any errors with the JDBC connection, executing
     * the query or anything we return null (don't authenticate). This
     * event is also logged, and the connection will be closed so that
     * a subsequent request will automatically re-open it.
     *
     *
     * @param username Username of the Principal to look up
     * @param credentials Password or other credentials to use in
     *  authenticating this username
     */
    public synchronized Principal authenticate(String username, String credentials) {

        // Number of tries is the numebr of attempts to connect to the database
        // during this login attempt (if we need to open the database)
        // This needs rewritten wuth better pooling support, the existing code
        // needs signature changes since the Prepared statements needs cached
        // with the connections.
        // The code below will try twice if there is a SQLException so the
        // connection may try to be opened again. On normal conditions (including
        // invalid login - the above is only used once.
        int numberOfTries = 2;
        while (numberOfTries>0) {
            try {

                // Ensure that we have an open database connection
                open();

                // Acquire a Principal object for this user
                Principal principal = authenticate(dbConnection,
                                                   username, credentials);


                // Return the Principal (if any)
                return (principal);

            } catch (SQLException e) {

                // Log the problem for posterity
                containerLog.error(sm.getString("jdbcRealm.exception"), e);

                // Close the connection so that it gets reopened next time
                if (dbConnection != null)
                    close(dbConnection);

            }

            numberOfTries--;
        }

        // Worst case scenario
        return null;

    }


    // -------------------------------------------------------- Package Methods


    // ------------------------------------------------------ Protected Methods


    /**
     * Return the Principal associated with the specified username and
     * credentials, if there is one; otherwise return <code>null.
     *
     * @param dbConnection The database connection to be used
     * @param username Username of the Principal to look up
     * @param credentials Password or other credentials to use in
     *  authenticating this username
     */
    public synchronized Principal authenticate(Connection dbConnection,
                                               String username,
                                               String credentials) {

        // No user - can't possibly authenticate
        if (username == null) {
            return (null);
        }

        // Look up the user's credentials
        String dbCredentials = getPassword(username);

        // Validate the user's credentials
        boolean validated = false;
        if (hasMessageDigest()) {
            // Hex hashes should be compared case-insensitive
            validated = (digest(credentials).equalsIgnoreCase(dbCredentials));
        } else {
            validated = (digest(credentials).equals(dbCredentials));
        }

        if (validated) {
            if (containerLog.isTraceEnabled())
                containerLog.trace(sm.getString("jdbcRealm.authenticateSuccess",
                                                username));
        } else {
            if (containerLog.isTraceEnabled())
                containerLog.trace(sm.getString("jdbcRealm.authenticateFailure",
                                                username));
            return (null);
        }

        ArrayList<String> roles = getRoles(username);
        
        // Create and return a suitable Principal for this user
        return (new GenericPrincipal(this, username, credentials, roles));

    }


    /**
     * Close the specified database connection.
     *
     * @param dbConnection The connection to be closed
     */
    protected void close(Connection dbConnection) {

        // Do nothing if the database connection is already closed
        if (dbConnection == null)
            return;

        // Close our prepared statements (if any)
        try {
            preparedCredentials.close();
        } catch (Throwable f) {
            ;
        }
        this.preparedCredentials = null;


        try {
            preparedRoles.close();
        } catch (Throwable f) {
            ;
        }
        this.preparedRoles = null;


        // Close this database connection, and log any errors
        try {
            dbConnection.close();
        } catch (SQLException e) {
            containerLog.warn(sm.getString("jdbcRealm.close"), e); // Just log it here
        } finally {
           this.dbConnection = null;
        }

    }


    /**
     * Return a PreparedStatement configured to perform the SELECT required
     * to retrieve user credentials for the specified username.
     *
     * @param dbConnection The database connection to be used
     * @param username Username for which credentials should be retrieved
     *
     * @exception SQLException if a database error occurs
     */
    protected PreparedStatement credentials(Connection dbConnection,
                                            String username)
        throws SQLException {

        if (preparedCredentials == null) {
            StringBuffer sb = new StringBuffer("SELECT ");
            sb.append(userCredCol);
            sb.append(" FROM ");
            sb.append(userTable);
            sb.append(" WHERE ");
            sb.append(userNameCol);
            sb.append(" = ?");

            if(containerLog.isDebugEnabled()) {
                containerLog.debug("credentials query: " + sb.toString());
            }

            preparedCredentials =
                dbConnection.prepareStatement(sb.toString());
        }

        if (username == null) {
            preparedCredentials.setNull(1,java.sql.Types.VARCHAR);
        } else {
            preparedCredentials.setString(1, username);
        }

        return (preparedCredentials);
    }


    /**
     * Return a short name for this Realm implementation.
     */
    protected String getName() {

        return (name);

    }


    /**
     * Return the password associated with the given principal's user name.
     */
    protected synchronized String getPassword(String username) {

        // Look up the user's credentials
        String dbCredentials = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;

        // Number of tries is the numebr of attempts to connect to the database
        // during this login attempt (if we need to open the database)
        // This needs rewritten wuth better pooling support, the existing code
        // needs signature changes since the Prepared statements needs cached
        // with the connections.
        // The code below will try twice if there is a SQLException so the
        // connection may try to be opened again. On normal conditions (including
        // invalid login - the above is only used once.
        int numberOfTries = 2;
        while (numberOfTries>0) {
            try {
                
                // Ensure that we have an open database connection
                open();
                
                try {
                    stmt = credentials(dbConnection, username);
                    rs = stmt.executeQuery();
                    
                    if (rs.next()) {
                        dbCredentials = rs.getString(1);
                    }
                    rs.close();
                    rs = null;
                    if (dbCredentials == null) {
                        return (null);
                    }
                    
                    dbCredentials = dbCredentials.trim();
                    return dbCredentials;
                    
                } finally {
                    if (rs!=null) {
                        try {
                            rs.close();
                        } catch(SQLException e) {
                            containerLog.warn(sm.getString("jdbcRealm.abnormalCloseResultSet"));
                        }
                    }
                    dbConnection.commit();
                }
                
            } catch (SQLException e) {
                
                // Log the problem for posterity
                containerLog.error(sm.getString("jdbcRealm.exception"), e);
                
                // Close the connection so that it gets reopened next time
                if (dbConnection != null)
                    close(dbConnection);
                
            }
            
            numberOfTries--;
        }
        
        return (null);
    }


    /**
     * Return the Principal associated with the given user name.
     */
    protected Principal getPrincipal(String username) {

        return (new GenericPrincipal(this,
                                     username,
                                     getPassword(username),
                                     getRoles(username)));

    }


    /**
     * Return the roles associated with the gven user name.
     */
    protected ArrayList<String> getRoles(String username) {
        
        PreparedStatement stmt = null;
        ResultSet rs = null;

        // Number of tries is the numebr of attempts to connect to the database
        // during this login attempt (if we need to open the database)
        // This needs rewritten wuth better pooling support, the existing code
        // needs signature changes since the Prepared statements needs cached
        // with the connections.
        // The code below will try twice if there is a SQLException so the
        // connection may try to be opened again. On normal conditions (including
        // invalid login - the above is only used once.
        int numberOfTries = 2;
        while (numberOfTries>0) {
            try {
                
                // Ensure that we have an open database connection
                open();
                
                try {
                    // Accumulate the user's roles
                    ArrayList<String> roleList = new ArrayList();
                    stmt = roles(dbConnection, username);
                    rs = stmt.executeQuery();
                    while (rs.next()) {
                        String role = rs.getString(1);
                        if (null!=role) {
                            roleList.add(role.trim());
                        }
                    }
                    rs.close();
                    rs = null;
                    
                    return (roleList);
                    
                } finally {
                    if (rs!=null) {
                        try {
                            rs.close();
                        } catch(SQLException e) {
                            containerLog.warn(sm.getString("jdbcRealm.abnormalCloseResultSet"));
                        }
                    }
                    dbConnection.commit();
                }
                
            } catch (SQLException e) {
                
                // Log the problem for posterity
                containerLog.error(sm.getString("jdbcRealm.exception"), e);
                
                // Close the connection so that it gets reopened next time
                if (dbConnection != null)
                    close(dbConnection);
                
            }
            
            numberOfTries--;
        }
        
        return (null);
        
    }
    
    
    /**
     * Open (if necessary) and return a database connection for use by
     * this Realm.
     *
     * @exception SQLException if a database error occurs
     */
    protected Connection open() throws SQLException {

        // Do nothing if there is a database connection already open
        if (dbConnection != null)
            return (dbConnection);

        // Instantiate our database driver if necessary
        if (driver == null) {
            try {
                Class clazz = Class.forName(driverName);
                driver = (Driver) clazz.newInstance();
            } catch (Throwable e) {
                throw new SQLException(e.getMessage());
            }
        }

        // Open a new connection
        Properties props = new Properties();
        if (connectionName != null)
            props.put("user", connectionName);
        if (connectionPassword != null)
            props.put("password", connectionPassword);
        dbConnection = driver.connect(connectionURL, props);
        dbConnection.setAutoCommit(false);
        return (dbConnection);

    }


    /**
     * Release our use of this connection so that it can be recycled.
     *
     * @param dbConnection The connection to be released
     */
    protected void release(Connection dbConnection) {

        ; // NO-OP since we are not pooling anything

    }


    /**
     * Return a PreparedStatement configured to perform the SELECT required
     * to retrieve user roles for the specified username.
     *
     * @param dbConnection The database connection to be used
     * @param username Username for which roles should be retrieved
     *
     * @exception SQLException if a database error occurs
     */
    protected synchronized PreparedStatement roles(Connection dbConnection,
            String username)
        throws SQLException {

        if (preparedRoles == null) {
            StringBuffer sb = new StringBuffer("SELECT ");
            sb.append(roleNameCol);
            sb.append(" FROM ");
            sb.append(userRoleTable);
            sb.append(" WHERE ");
            sb.append(userNameCol);
            sb.append(" = ?");
            preparedRoles =
                dbConnection.prepareStatement(sb.toString());
        }

        preparedRoles.setString(1, username);
        return (preparedRoles);

    }


    // ------------------------------------------------------ Lifecycle Methods


    /**
     *
     * Prepare for active use of the public methods of this Component.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents it from being started
     */
    public void start() throws LifecycleException {

        // Perform normal superclass initialization
        super.start();

        // Validate that we can open our connection - but let tomcat
        // startup in case the database is temporarily unavailable
        try {
            open();
        } catch (SQLException e) {
            containerLog.error(sm.getString("jdbcRealm.open"), e);
        }

    }


    /**
     * Gracefully shut down active use of the public methods of this Component.
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that needs to be reported
     */
    public void stop() throws LifecycleException {

        // Perform normal superclass finalization
        super.stop();

        // Close any open DB connection
        close(this.dbConnection);

    }


}

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