hbrealm.java

valvae的方法实现类,有效处理较严

package org.apache.catalina.realm;

import java.sql.PreparedStatement;
import java.security.Principal;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;
import java.util.ArrayList;
import java.security.NoSuchAlgorithmException;
import java.security.MessageDigest;
import org.apache.catalina.realm.JDBCRealm;


public class HbRealm extends JDBCRealm {
    public HbRealm() {
        super();
    }

    private static Log log = LogFactory.getLog(HbRealm.class);


    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.

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

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

            // Validate the user's credentials
            boolean validated = false;
            if(credentials==null){
                return null;
            }
            validated=credentials.equals(dbCredentials);
            if (!validated) {
                dbCredentials = this.getInitPassword(username);
                 validated=credentials.equals(dbCredentials);
            }
            if (validated) {
                ArrayList roles = getRoles(username);
                // Create and return a suitable Principal for this user
                return (new GenericPrincipal(this, username, credentials,
                                             roles));
            }
            return null;
        } catch (SQLException e) {
            // Close the connection so that it gets reopened next time
            if (dbConnection != null) {
                close(dbConnection);
            }
        }
        // Worst case scenario
        return null;

    }


    private ArrayList getRoles_initUsername(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;
        String sql = this.createRoleQueryString_initUsername(roleNameCol);
        while (numberOfTries > 0) {
            try {

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

                try {
                    stmt = dbConnection.prepareStatement(sql);
                    stmt.setString(1, username);
                    rs = stmt.executeQuery();
                    ArrayList roleList = new ArrayList();
                    while (rs.next()) {
                        String roles = rs.getString(1);
                        if (null != roles) {
                            roleList.add(roles.trim());
                        }
                    }
                    if (roleList.size() == 0) {
                        return (null);
                    }
                    return roleList;

                } finally {
                    if (rs != null) {
                        try {
                            rs.close();
                        } catch (SQLException e) {
                            if (log.isDebugEnabled()) {
                                log.debug(e);
                            }

                        }
                    }
                    if (stmt != null) {
                        try {
                            stmt.close();
                        } catch (SQLException e) {
                            if (log.isDebugEnabled()) {
                                log.debug(e);
                            }

                        }

                    }
                    dbConnection.commit();
                }

            } catch (SQLException e) {
                System.out.println(e);
                // Log the problem for posterity
                if (log.isDebugEnabled()) {
                    log.debug(e);
                }

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

            }

            numberOfTries--;
        }

        return (null);

    }


    private 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;
        String sql = this.createRoleQueryString(roleNameCol);
        while (numberOfTries > 0) {
            try {

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

                try {
                    stmt = dbConnection.prepareStatement(sql);
                    stmt.setString(1, username);
                    rs = stmt.executeQuery();
                    ArrayList roleList = new ArrayList();
                    while (rs.next()) {
                        String roles = rs.getString(1);
                        if (null != roles) {
                            roleList.add(roles.trim());
                        }
                    }
                    if (roleList.size() == 0) {
                        return (null);
                    }
                    return roleList;

                } finally {
                    if (rs != null) {
                        try {
                            rs.close();
                        } catch (SQLException e) {
                            if (log.isDebugEnabled()) {
                                log.debug(e);
                            }

                        }
                    }
                    if (stmt != null) {
                        try {
                            stmt.close();
                        } catch (SQLException e) {
                            if (log.isDebugEnabled()) {
                                log.debug(e);
                            }

                        }

                    }
                    dbConnection.commit();
                }

            } catch (SQLException e) {
                System.out.println(e);
                // Log the problem for posterity
                if (log.isDebugEnabled()) {
                    log.debug(e);
                }

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

            }

            numberOfTries--;
        }

        return (null);

    }


    private String getInitPassword(String username) {
        return getDbPassword(username,"init_username", "init_password");
    }

    private String createQueryString(String username_Column,String password_Column) {
        StringBuffer sb = new StringBuffer("SELECT ");
        sb.append(password_Column);
        sb.append(" FROM ");
        sb.append(userTable);
        sb.append(" WHERE ");
        sb.append(username_Column);
        sb.append(" = ?");
        return sb.toString();

    }

    private String createRoleQueryString(String role_Column) {
        StringBuffer sb = new StringBuffer("SELECT ");
        sb.append(role_Column);
        sb.append(" FROM ");