jdbcrealm.java

业界著名的tomcat服务器的最新6.0的源代码。

        // 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 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 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 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);

    }


}