An Implementation of Predicate

package parsian.mahmoud.oracle;
/*
 * JDBC Recipes: A Problem-Solution Approach (Problem-Solution Approach) (Hardcover) by Mahmoud
 * Parsian
 * 
 * 
 * # Publisher: Apress (September 15, 2005) # Language: English # ISBN: 1590595203
 */
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
 
import javax.sql.RowSet;
import javax.sql.rowset.FilteredRowSet;
import javax.sql.rowset.Predicate;
 
import com.sun.rowset.FilteredRowSetImpl;
 
public class Main1 {
    public static void main(String[] args) throws Exception {
	Connection conn = getHSQLConnection();
	System.out.println("Got Connection.");
	Statement st = conn.createStatement();
	st.executeUpdate("create table survey (id int,name varchar, age int);");
	st.executeUpdate("insert into survey (id,name,age ) values (1,'nameValue', 10)");
	st.executeUpdate("insert into survey (id,name,age ) values (2,'anotherValue', 100)");
 
	FilteredRowSet frs = new FilteredRowSetImpl();
	frs.setUsername("sa");
	frs.setPassword("");
	frs.setUrl("jdbc:hsqldb:data/tutorial");
	frs.setCommand("SELECT id, name, age FROM survey");
	frs.execute();
 
	System.out.println("--- Unfiltered RowSet: ---");
	while (frs.next()) {
	    System.out
		    .println(frs.getRow() + " - " + frs.getString("id") + ":" + frs.getString("name") + ":" + frs.getInt("age"));
	}
	// create a filter that restricts entries in
	// the age column to be between 7 and 10
	AgeFilter filter = new AgeFilter(7, 10, 3);
 
	// set the filter.
	frs.beforeFirst();
	frs.setFilter(filter);
 
	// go to the beginning of the Rowset
	System.out.println("--- Filtered RowSet: ---");
 
	// show filtered data
	while (frs.next()) {
	    System.out
		    .println(frs.getRow() + " - " + frs.getString("id") + ":" + frs.getString("name") + ":" + frs.getInt("age"));
	}
 
	System.out.println("--- Try to insert new records ---");
 
	// Try to add an employee with age = 90 (allowed by filter)
	frs.moveToInsertRow();
	frs.updateString(1, "999");
	frs.updateString(2, "Andre");
	frs.updateInt(3, 90);
	frs.insertRow();
	frs.moveToCurrentRow();
	frs.acceptChanges();
 
	// try to add an survey with age = 65 (not allowed by filter)
	frs.moveToInsertRow();
	frs.updateString(1, "123");
	frs.updateString(2, "Jeff");
	frs.updateInt(3, 65);
	frs.insertRow();
	frs.moveToCurrentRow();
	frs.acceptChanges();
 
	// scroll to first row of rowset
	frs.beforeFirst();
	// display rows in FilteredRowset
	System.out.println("FilteredRowSet after trying to insert Jeff (age 65) and Andre (age 90):");
	while (frs.next()) {
	    System.out
		    .println(frs.getRow() + " - " + frs.getString("id") + ":" + frs.getString("name") + ":" + frs.getInt("age"));
	}
 
	frs.close();
	st.close();
	frs.close();
    }
 
    private static Connection getHSQLConnection() throws Exception {
	Class.forName("org.hsqldb.jdbcDriver");
	System.out.println("Driver Loaded.");
	String url = "jdbc:hsqldb:data/tutorial";
	return DriverManager.getConnection(url, "sa", "");
    }
 
    public static Connection getMySqlConnection() throws Exception {
	String driver = "org.gjt.mm.mysql.Driver";
	String url = "jdbc:mysql://localhost/demo2s";
	String username = "oost";
	String password = "oost";
 
	Class.forName(driver);
	Connection conn = DriverManager.getConnection(url, username, password);
	return conn;
    }
 
    public static Connection getOracleConnection() throws Exception {
	String driver = "oracle.jdbc.driver.OracleDriver";
	String url = "jdbc:oracle:thin:@localhost:1521:databaseName";
	String username = "userName";
	String password = "password";
 
	Class.forName(driver); // load Oracle driver
	Connection conn = DriverManager.getConnection(url, username, password);
	return conn;
    }
}
 
class AgeFilter implements Predicate {
    private int lowAge;
 
    private int highAge;
 
    private int columnIndex;
 
    private String columnName;
 
    public AgeFilter(int lowAge, int highAge, int columnIndex, String columnName) {
	this.lowAge = lowAge;
	this.highAge = highAge;
	this.columnName = columnName;
	this.columnIndex = columnIndex;
    }
 
    public AgeFilter(int lowAge, int highAge, int columnIndex) {
	this(lowAge, highAge, columnIndex, "age");
    }
 
    public boolean evaluate(Object value, String columnName) {
	boolean evaluation = true;
	if (columnName.equalsIgnoreCase(this.columnName)) {
	    int columnValue = ((Integer) value).intValue();
	    if ((columnValue >= this.lowAge) && (columnValue <= this.highAge)) {
		evaluation = true;
	    } else {
		evaluation = false;
	    }
	}
	return evaluation;
    }
 
    public boolean evaluate(Object value, int columnNumber) {
	boolean evaluation = true;
	if (columnIndex == columnNumber) {
	    int columnValue = ((Integer) value).intValue();
	    if ((columnValue >= this.lowAge) && (columnValue <= this.highAge)) {
		evaluation = true;
	    } else {
		evaluation = false;
	    }
	}
	return evaluation;
    }
 
    public boolean evaluate(RowSet rs) {
	if (rs == null) {
	    return false;
	}
 
	FilteredRowSet frs = (FilteredRowSet) rs;
	boolean evaluation = false;
	try {
	    int columnValue = frs.getInt(this.columnIndex);
	    if ((columnValue >= this.lowAge) && (columnValue <= this.highAge)) {
		evaluation = true;
	    }
	} catch (SQLException e) {
	    return false;
	}
	return evaluation;
    }
}