source: greenstone3/trunk/src/java/org/greenstone/gsdl3/sql/derby/DerbyDBWrapper.java@ 16630

package org.greenstone.gsdl3.sql.derby;

import  org.greenstone.gsdl3.sql.*;


import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Statement;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;

import org.greenstone.gsdl3.util.DBInfo;

import org.apache.log4j.*;

public class DerbyDBWrapper implements MetadataDBWrapper{
    protected SQLServer sqlServer = null;
    protected SQLStatements sqlState = null;
    protected Connection connection = null; 
    protected Statement statement = null;
    protected static Logger logger = Logger.getLogger(org.greenstone.gsdl3.sql.derby.DerbyDBWrapper.class.getName());


    public DBInfo getInfo(String id){
    if(sqlState == null) return null;
        String dbInfoState = sqlState.getDBInfoStatement(id);
        ArrayList result = executeQuery(dbInfoState);
    if (result.size() == 0) return null;
    DBInfo info = new DBInfo();
    for(int i=0;  i<result.size();i++){
        HashMap arow = (HashMap)result.get(i);
        Iterator ite = arow.keySet().iterator();
        while(ite.hasNext()){
        String key = (String)ite.next();
        Object value = arow.get(key);
        //logger.info(key + "=>" +value);
        if (value == null || value.equals("")) continue;
        info.addInfo(key.toLowerCase(),sqlState.undoDBSafe(value));
        }
    }

    return info;
    }

    public void setSQLServer(SQLServer server){
    sqlServer = server;
    }

    public void setSQLStatements(SQLStatements state){
    sqlState = state;
    }

    public boolean openConnection(String databasepath){
    connection = sqlServer.connect(databasepath);
    
    if (connection == null) return false;

    try{
        connection.setAutoCommit(false);    
        statement = connection.createStatement();
    }
    catch(SQLException sqle){
        logger.error("Database Error occured when creating a statement object",sqle);
        return false;
    }
    return true;
    }

    //return a list of rows array->hashmap
    public synchronized ArrayList executeQuery(String query_statement){
    //the database hasn't been correct yet
        ArrayList results = new ArrayList();
    try{    
        
        if (statement == null){
            logger.info("the database hasn't been correct yet");
            return new ArrayList();
        }
    
        ResultSet rs = statement.executeQuery(query_statement);
        ResultSetMetaData rsmd = rs.getMetaData();
        int numOfColumns = rsmd.getColumnCount();
        while(rs.next()){
           HashMap arow = new HashMap();
           for(int i = 1; i <= numOfColumns ; i++){
           arow.put(rsmd.getColumnName(i).toLowerCase(), rs.getObject(i));
           }
           results.add(arow);  
       }
    }
    catch(SQLException sqle){
        logger.error("Database Error occured when executeQuery " + query_statement,sqle);
        return results;
    }
    return results;
    }
    
     /** check for the existence of a table**/
    public boolean check4Table (String check_table) {
         try {
      statement.execute(check_table);
      }  catch (SQLException sqle) {
      String theError = (sqle).getSQLState();
      if (theError.equals("42X05"))   // Table does not exist
          { 
          return false;
          }   
      else{
          return true;
      }
      }
      //  System.out.println("Just got the warning - table exists OK ");
      return true;
    }   

    public void closeConnection(String databasepath){
    sqlServer.disconnect(databasepath);
    }
  
 }