assignmentdaoimpl.java~

J2EE & Tomcat books published by hope

/*
 */

package com.sun.j2ee.workflow.assignment.dao;

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Collection;

import javax.sql.DataSource;
import javax.naming.InitialContext;
import javax.naming.Context;
import javax.naming.NamingException;

import com.sun.j2ee.workflow.util.JNDINames;
import com.sun.j2ee.workflow.assignment.dao.AssignmentDAO;
import com.sun.j2ee.workflow.util.DatabaseNames;
import com.sun.j2ee.workflow.assignment.model.AssignmentModel;

import com.sun.j2ee.workflow.assignment.exceptions.AssignmentDAOSysException;
import com.sun.j2ee.workflow.assignment.exceptions.AssignmentDAOAppException;
import com.sun.j2ee.workflow.assignment.exceptions.AssignmentDAODBUpdateException;
import com.sun.j2ee.workflow.assignment.exceptions.AssignmentDAOFinderException;
import com.sun.j2ee.workflow.assignment.exceptions.AssignmentDAODupKeyException;

import com.sun.j2ee.workflow.util.Debug;

/**
 * This class calls the simple Datasource from Tomcat to get connection
 * No connection pooling is used.
 */
public class AssignmentDAOImpl implements AssignmentDAO {

    private transient Connection dbConnection = null;
    private transient DataSource datasource   = null;

    public AssignmentDAOImpl() throws AssignmentDAOSysException {
        try {
            InitialContext ic = new InitialContext();
            datasource = (DataSource) ic.lookup(JNDINames.WORKFLOW_DATASOURCE);
        } catch (NamingException ne) {
            throw new AssignmentDAOSysException("Naming Exception while looking "
                                             + " up DataSource Connection " +
                                                JNDINames.WORKFLOW_DATASOURCE +
                                                    ": \n" + ne.getMessage());
        }
    }
/*
    public void query{
        
        // load the PoolMan JDBC Driver
        try {
            Class.forName("com.codestudio.sql.PoolMan").newInstance();
        } catch (Exception ex) {
            System.out.println("Could Not Find the PoolMan Driver. " +
                               "Is poolman.jar in your CLASSPATH?");
            System.exit(0);
        }

        // establish a Connection to the last database listed in the 'poolman.props' file
        Connection con = DriverManager.getConnection("jdbc:poolman");

        try {

            Statement s = con.createStatement();
            ResultSet res = s.executeQuery(sql);
            ResultSetMetaData meta = res.getMetaData();

            int cols = meta.getColumnCount();
            while (res.next()) {
                for (int i = 1; i <= cols; i++) {
                    Object val = res.getObject(i);
                    System.out.print("\t" + meta.getColumnLabel(i) + ": ");
                    System.out.print(val == null ? " " : val.toString());
                }
                System.out.print("\n");
            }
        } catch (SQLException sqe) {
        }
        finally {
            // this close method merely returns the Connection to the pool
            // after implicitly closing related resources (Statements and ResultSets)
            con.close();
            System.out.println("SAMPLE: Closed Con");
        }


    }
 */
    public void create(AssignmentModel assignmentinfo) throws AssignmentDAOSysException, AssignmentDAODupKeyException, AssignmentDAODBUpdateException, AssignmentDAOAppException {
        insertassignment(assignmentinfo);
    }

    public AssignmentModel load(String id) throws AssignmentDAOSysException, AssignmentDAOFinderException {
        return(selectassignment(id));
    }

    public void store(AssignmentModel assignmentinfo) throws AssignmentDAODBUpdateException, AssignmentDAOAppException, AssignmentDAOSysException  {
        updateassignment(assignmentinfo);
    }

    public void remove(String id) throws AssignmentDAODBUpdateException, AssignmentDAOSysException {
        deleteassignment(id);
    }

    public String findByPrimaryKey(String assignmentId) throws AssignmentDAOFinderException, AssignmentDAOSysException {
        if (assignmentExists(assignmentId))
            return (assignmentId);
        throw new AssignmentDAOFinderException("primary key not found :"+assignmentId);
    }

    private boolean assignmentExists (String assignmentId) throws AssignmentDAOSysException {
        PreparedStatement stmt = null;
        ResultSet result = null;
        boolean returnValue = false;
        String queryStr ="SELECT assign_ID FROM " +
                    DatabaseNames.ASSIGNMENT_TABLE
                        + " WHERE assign_ID = " + "'" + assignmentId.trim() + "'";
        Debug.println("queryString is: "+ queryStr);

        try {
            getDBConnection();
            stmt = createPreparedStatement(dbConnection, queryStr);
            result = stmt.executeQuery();
            if ( !result.next() ) {
                returnValue = false;
            } else {
                assignmentId = result.getString(1);
                returnValue = true;
            }
        } catch(SQLException se) {
            throw new AssignmentDAOSysException(
                           "SQLException while checking for an"
                           + " existing assignment - id -> " + assignmentId + " :\n" + se);
        } finally {
            closeResultSet(result);
            closeStatement(stmt);
            closeConnection();
        }
        return returnValue;
    }

    private boolean isValidData(AssignmentModel assignmentinfo) {
        if ( (assignmentinfo.getAssign_ID() == null) ||
             (assignmentinfo.getAssign_name() == null) || 
             (assignmentinfo.getDesc() == null) )
            return (false);
        else
            return (true);
    }

    private void insertassignment(AssignmentModel assignmentinfo) throws
                                 AssignmentDAOSysException,
                                 AssignmentDAODupKeyException,
                                 AssignmentDAODBUpdateException,
                                 AssignmentDAOAppException {

        if (!isValidData(assignmentinfo))
            throw new AssignmentDAOAppException("Illegal data values for insert");
        if (assignmentExists(assignmentinfo.getAssign_ID()))
            throw new AssignmentDAODupKeyException("assignment exists for "+
                                                assignmentinfo.getAssign_ID());

        PreparedStatement stmt = null;
        String queryStr = "INSERT INTO " + DatabaseNames.ASSIGNMENT_TABLE
            +"(assign_ID, assign_name, task, user, desc, comment) "
            + "VALUES ("
            + "'" + assignmentinfo.getAssign_ID().trim() + "',"
            + "'" + assignmentinfo.getAssign_name().trim() + "',"
            + "'" + assignmentinfo.getTask().trim() + "',"
            + "'" + assignmentinfo.getUser().trim() + "',"
            + "'" + assignmentinfo.getDesc().trim() + "',"
            + "'" + assignmentinfo.getComment().trim() + "')";

 
        Debug.println("queryString is: "+ queryStr);

        try {
            getDBConnection();
            stmt = createPreparedStatement(dbConnection, queryStr);
            int resultCount = stmt.executeUpdate();

            if ( resultCount != 1 ) {
                throw new AssignmentDAODBUpdateException(
                    "ERROR in ASSIGNMENT_TABLE INSERT !! resultCount = " +
                                   resultCount);
            }
        } catch(SQLException ae) {
            throw new AssignmentDAOSysException(
                        "SQLException while inserting new " +
                        "assignment; id = " + assignmentinfo.getAssign_ID() + " :\n" + ae);
        } finally {
            closeStatement(stmt);
            closeConnection();
        }
    }

    private AssignmentModel selectassignment(String assignmentId) throws
                                         AssignmentDAOSysException,
                                         AssignmentDAOFinderException {

        PreparedStatement stmt = null;
        ResultSet result = null;

        String queryStr = "SELECT *"+
                    " FROM " + DatabaseNames.ASSIGNMENT_TABLE +
                        " WHERE assign_ID = " + "'" + assignmentId.trim() + "'";
        Debug.println("queryString is: "+ queryStr);

        try {
            getDBConnection();
            stmt = createPreparedStatement(dbConnection, queryStr);
            result = stmt.executeQuery();
            if ( !result.next() )
                throw new AssignmentDAOFinderException(
                                  "No record for primary key " + assignmentId);

            int i = 1;
            String assign_ID = result.getString(i++);
            String assign_name = result.getString(i++);
            String task = result.getString(i++);
            String user = result.getString(i++);
            String desc = result.getString(i++);
            String comment = result.getString(i++);
            
            return(new AssignmentModel(assign_ID, assign_name, task, user, desc, comment ));