ProjectDAO.java

package repository;

/**
 * @author Xuesong Meng&Yidu Liang
 * @author Joanne Zhuo
 */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class ProjectDAO {

    public final static String PROJECT_NAME = "ClubUML";
    public final static String PROJECT_Desc = "ClubUML First Project";
    public final static byte PROJECT_Achived = 0;

    /**
     * Get projectID
     * 
     * @return projectId int
     */
    public static int getProjectId() {
	int projectId = -1;
	try {
	    Connection conn = DbManager.getConnection();
	    projectId = retrieveProject(conn);
	    if (projectId == 0) {
		// If we don't have the project existed in DB, then create one first
		addProject(conn);
		// retrieve the newly added project
		projectId = retrieveProject(conn);
	    }
	    conn.close();
	} catch (SQLException e) {
	    System.out.println("Using default model.");
	}
	return projectId;
    }

    /**
     * Retrieve projectID from DB
     * 
     * @param conn
     * 			Established connection
     * @return projectId int
     *          return 0 if no exist 
     */
    public static int retrieveProject(Connection conn) {
	int projectId = 0;
	try {
	    PreparedStatement pstmt = conn.prepareStatement(
		    "SELECT * FROM project where projectName = ? ;");
	    pstmt.setString(1, PROJECT_NAME);

	    // Execute the SQL statement and store result into the ResultSet
	    ResultSet rs = pstmt.executeQuery();
	    if (rs.next()) {
		projectId = rs.getInt("project_Id");
	    }
	    rs.close();
	    pstmt.close();

	} catch (SQLException e) {
	    System.out.println("Using default model.");
	}
	return projectId;
    }

    /**
     * Add our default project into DB (project name, description, archived)
     * 			
     * @param conn
     * 			Established connection
     * @return true if success; false if fail
     */
    public static boolean addProject(Connection conn) {
	try {
		// modified by Xuesong Meng
	    PreparedStatement pstmt = conn.prepareStatement(
		    "INSERT into project(projectName, starDate ,description) VALUES(?,NOW(),?);");
	    pstmt.setString(1, PROJECT_NAME);
	    pstmt.setString(2, PROJECT_Desc);
	    //pstmt.setByte(3, PROJECT_Achived);

	    // Execute the SQL statement and update database accordingly.
	    pstmt.executeUpdate();
	    pstmt.close();
	} catch (SQLException e) {
	    e.printStackTrace();
	    return false;
	}
	return true;
    }

    /**
     * Remove a project from DB
     * 
     * @return true if success; false if fail  
     */
    public static boolean removeProject() {
	try {
	    Connection conn = DbManager.getConnection();
	    PreparedStatement pstmt = conn.prepareStatement(
		    "DELETE FROM project where projectName = ?;");
	    pstmt.setString(1, PROJECT_NAME);

	    // Execute the SQL statement and update database accordingly.
	    pstmt.executeUpdate();

	    pstmt.close();
	    conn.close();
	    return true;
	} catch (SQLException e) {
	    throw new IllegalArgumentException(e.getMessage(), e);
	}
    }
}