src/dochelper/JdbcTableRecordSet.java

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/*
 * JdbcTableRecordSet.java
 *
 * Created on January 19, 2009, 9:44 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */
package dochelper;

import dochelper.exceptions.InvalidValueException;
import dochelper.exceptions.MissingArgumentException;
import dochelper.exceptions.ResourceUnavailableException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class JdbcTableRecordSet extends AbstractTableRecordSet {

    protected String USER = "user";

    protected String PASS = "pass";

    protected String URL = "url";

    protected String DRIVER = "driver";

    protected String TABLE = "tablename";

    protected String FIELDS = "fields";

    protected String FILTER = "whereclause";

    private ArrayList<Record> records = new ArrayList<Record>();

    protected void initImpl() throws SQLException, ResourceUnavailableException {

        String url = (String)params.get(URL);
        String pass = (String)params.get(PASS);
        String user = (String)params.get(USER);

        Connection conn;
        try {
            conn = DriverManager.getConnection(url, user, pass);
        }
        catch (Exception e) {
            throw new ResourceUnavailableException("Unable to connection to Database. \n" + e.getMessage());
        }

        //fetch the records
        fetchRecords(conn);

    }

    protected void checkParamsImpl() throws MissingArgumentException, InvalidValueException, ResourceUnavailableException {

        //Validate the user is set
        if (!params.containsKey(USER))
            throw new MissingArgumentException(USER);

        //Validate the url is set
        if (!params.containsKey(URL))
            throw new MissingArgumentException(URL);

        //Validate the dirver is set
        if (!params.containsKey(DRIVER))
            throw new MissingArgumentException(DRIVER);

        //Validate the table is set
        if (!params.containsKey(TABLE))
            throw new MissingArgumentException(TABLE);

        //Validate the table is set
        if (!params.containsKey(FIELDS))
            throw new MissingArgumentException(FIELDS);

        //check the dirver is accessible 
        try {
            System.out.println("Trying to load class:" + (String)params.get(DRIVER));
            Class.forName((String)params.get(DRIVER));
        }
        catch (ClassNotFoundException cnfe) {
            throw new ResourceUnavailableException();
        }

    }

    protected List<Record> getRecords() throws ResourceUnavailableException, SQLException {
        return records;
    }

    protected void fetchRecords(Connection conn) throws SQLException {

        //Create the query
        Statement s = conn.createStatement();
        String query = "SELECT * FROM " + (String)params.get(TABLE);

        String where = (String)params.get(FILTER);
        if (where != null)
            query += " WHERE " + where;

        System.out.println("Query: " + query);

        //execute the query
        s.executeQuery(query);


        ResultSet rs = s.getResultSet();
        String[] fields = ((String)params.get(FIELDS)).split(",");

        //make each Record by fetching the fields within it
        while (rs.next()) {
            //For each row, create a field,value hashmap
            HashMap<String, Object> fieldValues = new HashMap<String, Object>();
            HashMap<String, Object> fullFieldValues = new HashMap<String, Object>();

            ResultSetMetaData rsMeta = rs.getMetaData();

            //Create Searched field map
            for (int i = 0;i < fields.length;i++) {
                fieldValues.put(fields[i], rs.getObject(fields[i]));
            }

            //create the full fields map
            for (int i = 1;i < rsMeta.getColumnCount();i++) {
                Object value = rs.getObject(i);
                if (value == null) value = new String("null");
                fullFieldValues.put(rsMeta.getColumnName(i), value);
            }

            //make the records
            TableRecord record = new TableRecord(fieldValues, fullFieldValues, this.getName() + "Record");

            records.add(record);
        }

        //Close Record Set
        rs.close();
        s.close();

    }
}

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