同步LDAP和数据库的一个例子

import  java.io.File;
import  java.io.FileInputStream;
import  java.io.IOException;
import  java.sql.CallableStatement;
import  java.sql.Connection;
import  java.util.ArrayList;
import  java.util.Date;
import  java.util.Hashtable;
import  java.util.List;
import  java.util.Properties;
import  java.util.Timer;
import  java.util.TimerTask;

import  javax.naming.Context;
import  javax.naming.NamingEnumeration;
import  javax.naming.directory.Attribute;
import  javax.naming.directory.SearchControls;
import  javax.naming.directory.SearchResult;
import  javax.naming.ldap.Control;
import  javax.naming.ldap.InitialLdapContext;
import  javax.naming.ldap.LdapContext;
import  javax.servlet.ServletException;

import  org.apache.log4j.Logger;

import  com.sun.jndi.ldap.ctl.PagedResultsControl;
import  com.sun.jndi.ldap.ctl.PagedResultsResponseControl;

/** */ /**
 * Servlet implementation class for Servlet: SyncLDAPServlet
 * 
 * @web.servlet name="SyncLDAPServlet" display-name="SyncLDAPServlet"
 * 
 * @web.servlet-mapping url-pattern="/SyncLDAPServlet"
 *  
 */
public   class  SyncLDAPServlet  extends  javax.servlet.http.HttpServlet  implements
        javax.servlet.Servlet  ... {
    /**//*
     * (non-Java-doc)
     * 
     * @see javax.servlet.http.HttpServlet#HttpServlet()
     */
    private static Logger log = Logger.getLogger(SyncLDAPServlet.class);

    private Connection con;
    
    private static Hashtable env = null;

    List objList;

    private String REMOVE_NEW_DATA = "";//Stored procedure name for removing data

    private String INSERT_NEW_DATA = "";//Stored procedure name for insert new data

                     private String LDAP_PROPERTY_FILE = "";//LDAP property file, which contains LDAP connection info


    public void init() throws ServletException ...{
        super.init();

        this.con = null;
        this.emeList = new ArrayList();

        long interval = Long
                .valueOf(AppProperties.getProperty("LDAP.interval"))
                .longValue();
        Timer timer = new Timer();
        timer.schedule(new TimerTask() ...{
            public void run() ...{
                sncronizeEmployeeFromLDAP();
            }
        }, new Date(), interval);
    }

    /** *//**
     * This Servlet runs on WAS, so it get DB Connection from WAS
     * 
     * @param sql
     * @return
     */
    private void setDBConnection() ...{
        if (con == null) ...{
            try ...{
                     con = DataSourceFactory.getConnection();//Get DataSource con from appserver
                con.setAutoCommit(false);
                log.info("Connected to DB successfully!");
            } catch (Exception e) ...{
                log.error("Cannot connect to DB by AppServer", e);
            }
        }
    }

    /** *//**
     * 
     * @param sql
     * @return
     */
    private CallableStatement getStatement(String sql) ...{
        CallableStatement smt = null;
        if (con == null)
            return null;
        try ...{
            smt = con.prepareCall(sql);
        } catch (Exception ex) ...{
            log.error("Cannot create statement: " + sql, ex);
            return null;
        }
        return smt;
    }
        
    /** *//**
     * 
     *  
     */
    private void getAllDataFromLDAP() ...{
        Properties ldapContextSettings = null;
        ldapContextSettings = new Properties();
        String filePath = null;
        try ...{
            filePath = AppProperties.getProperty(this.LDAP_PROPERTY_FILE);
        } catch (NullPointerException e) ...{
            log.error("Cannot get LDAP Properties File.", e);
            return;
        }
        FileInputStream in = null;
        try ...{
            File file = new File(filePath);
            in = new FileInputStream(file);
            ldapContextSettings.load(in);
        } catch (IOException ioe) ...{
            log.error("Cannot open LDAP Property File: " + filePath, ioe);
            return;
        } finally ...{
            try ...{
                in.close();
            } catch (Exception excep) ...{
                log.error("Failed to close FileInputStream ", excep);
            }
        }        
//         create LDAP Connection
        String INITIAL_CONTEXT_FACTORY = (String) ldapContextSettings
                .getProperty("INITIAL_CONTEXT_FACTORY");
        String PROVIDER_URL = (String) ldapContextSettings
                .getProperty("LDAP_SERVER_URL");        
        String userID = (String) ldapContextSettings
                .getProperty("LDAP_ACCOUNT_NAME");        
        
        String userPW = this.getPasswd(userID);//Replace this with your own password maker    
        
        Hashtable env = new Hashtable();
        env.put(Context.SECURITY_AUTHENTICATION, "simple");
        env.put(Context.INITIAL_CONTEXT_FACTORY, INITIAL_CONTEXT_FACTORY);
        env.put(Context.PROVIDER_URL, PROVIDER_URL);
        env.put(Context.SECURITY_PRINCIPAL, userID);
        env.put(Context.SECURITY_CREDENTIALS, userPW);

        LdapContext ctx;
        try ...{
            ctx = new InitialLdapContext(env, null);
        } catch (Exception othere) ...{
            log.error("User "" + userID+ "" cannot log on to LDAP with passwd ""
                    + userPW + "", so exit!",othere);
            return;
        }
        log
                .info("User "" + userID
                        + "" has successfully logged on to LDAP Server at "
                        + new Date());

        objList = new ArrayList();
        try ...{
            SearchControls controls = new SearchControls();
            String filter = "Your own filter";
            controls.setSearchScope(SearchControls.SUBTREE_SCOPE);
            int pageSize = 500;
            try ...{
                ctx.setRequestControls(new Control[] ...{ new PagedResultsControl(
                    pageSize) });//Paged Searching for >= 1000 records
            } catch (IOException e) ...{
                log.error("LDAP Context set request control error:", e);
            }
            byte[] cookie = null;
            int count = 0;
            int pageCount = 0;
            NamingEnumeration results = null;
            SearchResult searchResult;
            javax.naming.directory.Attributes attrs;
            Attribute attr;
            do ...{
                results = ctx.search("DC=your_own_name", filter,
                        controls);
                if (results != null) ...{
                    pageCount ++;
                    while (results.hasMore()) ...{
                        searchResult = (SearchResult) results.next();
                        attrs = searchResult.getAttributes();
                        if (attrs != null) ...{        
                        JavaBean jb = new JavaBean();
                        count++;
                        if ((attr = attrs.get("attName")) != null)
                                                                                                                                               jb.setAProperty((String) attr.getAll().next());
                                          objList.add(jb);                            }
                }

                // Get the next LDAP page info
                cookie =
                    ((PagedResultsResponseControl) ctx
                        .getResponseControls()[0])
                        .getCookie();
                if (cookie != null) ...{                    
                    log.info("-----------NEXT--PAGE("+pageCount+")-------");
                    try ...{
                        ctx.setRequestControls(
                            new Control[] ...{
                                 new PagedResultsControl(
                                    pageSize,
                                    cookie,
                                    Control.CRITICAL)});
                    } catch (IOException e2) ...{
                        log.error("Failed to get next paged data from LDAP",e2);
                    }
                }                
            } while (cookie != null);
            log.info("All Records Number: " + count);
        } catch (Exception err) ...{
            log.info("Get Data from LDAP Failed", err);
        } finally ...{
            try ...{
                ctx.close();
            } catch (Exception closeErr) ...{
                log.error("Close LdapContext Failed", closeErr);
            }
        }
    }

    /** *//**
     * 
     * @param uid
     * @return
     */
    private String getPasswd(String uid) ...{
        //your own password maker
                                          return null;
    }

    private void removeOldData() throws Exception ...{
        log.info("Remove old data at " + new Date());
        String sql = "{call " + this.REMOVE_OLD_DATA + "}";
        CallableStatement smt = this.getStatement(sql);
        smt.execute();
        smt.close();
    }

    private void insertNewData() throws Exception ...{
        log.info("Insert new data at " + new Date());
        String sql = "{call " + this.INSERT_SS_EMPLOYEE + " (?)}";
        CallableStatement smt = this.getStatement(sql);
        if (smt == null)
            return;
        int len = objList.size();
        JavaBean jb = null;
        for (int i = 0; i < len; i++) ...{
            jb = (JavaBean) objList.get(i);
            smt.setString(1, jb.getAProperty());
            smt.addBatch();
        }
        smt.executeBatch();
        smt.close();
    }    

                     /** *//**
                      **The main entrance for these operators
                     */
    public void sncronizeEmployeeFromLDAP() ...{
        log.info("Start to Syncronize LDAP and DB at " + new Date());
        this.getAllDataFromLDAP();
        if ((objList == null) || (objList.size() < 1)) ...{
            log.error("No data got from LDAP, so exit!");
            return;
        }
        log.info("The number of to update: " + objList.size());
        this.setDBConnection();
        if (con == null) ...{
            log.error("Cannot connect to DB, so exit!");
            return;
        }
        try ...{
            this.removeOldData();
            this.insertNewData();
            con.commit();
        } catch (Exception e) ...{
            log.error("DB Operation Error, now try to roll back!", e);
            try ...{
                con.rollback();
            } catch (Exception ex) ...{
                log.error("Roll back Error!", ex);
            }
        } finally ...{
            try ...{
                con.close();
            } catch (Exception dbe) ...{
                log.error("Close DB connection Failed", dbe);
            }
        }
        log.info("End of Syncronizing at " + (new Date()));
    }
} Notice: 这只是我们一个完整项目中的一点，所以在代码中会用到其它包中的类或方法，我尽量避免了。如代码中的AppProperty就是这样的。因此，这里的代码是不能运行，需要根据实际作一定的修改。