Filtering Data in a RowSet - Java JDBC

Java examples for JDBC:FilteredRowSet

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Introduction

Use a FilteredRowSet to query the database and store the contents.

Demo Code

import com.sun.rowset.FilteredRowSetImpl;
import java.sql.Connection;
import java.sql.SQLException;
import javax.sql.RowSet;
import javax.sql.rowset.FilteredRowSet;

import javax.sql.rowset.Predicate;
public class Main {

    public static Connection conn = null;
    public static FilteredRowSet frs = null;

    public static void main(String[] args) throws Exception{
        String[] authorArray = {"DEA", "JUNEAU"};
        EmpFilter authorFilter = new EmpFilter(authorArray, 2);
        try {/*from ww w  .ja va 2s.  c o m*/
            frs = new FilteredRowSetImpl();
            frs.setCommand("SELECT TITLE, LASTNAME "
                    + "FROM Emp BA, "
                    + "     Project AW, "
                    + "     BOOK B "
                    + "WHERE AW.AUTHOR_ID = BA.ID "
                    + "AND B.ID = AW.BOOK_ID");

            frs.execute(conn);

            System.out.println("Prior to adding filter:");
            viewRowSet(frs);
            System.out.println("Adding author filter:");
            frs.beforeFirst();
            frs.setFilter(authorFilter);
            viewRowSet(frs);
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }

    public static void viewRowSet(RowSet rs) {
        try {
            while (rs.next()) {
                System.out.println(rs.getString(1) + " - "
                        + rs.getString(2));
            }
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }
}
class EmpFilter implements Predicate {
  private String[] authors;
  private String colName = null;
  private int colNumber = -1;
  public EmpFilter(String[] authors, int colNumber) {
    this.authors = authors;
    this.colNumber = colNumber;
    this.colName = null;
  }
  @Override
  public boolean evaluate(Object value, String colName) {

    if (colName.equalsIgnoreCase(this.colName)) {
        for (String author : this.authors) {
            if (author.equalsIgnoreCase((String)value)) {
                return true;
            }
        }
    }
    return false;
  }

  @Override
  public boolean evaluate(Object value, int colNumber) {

    if (colNumber == this.colNumber) {
        for (String author : this.authors) {
            if (author.equalsIgnoreCase((String)value)) {
                return true;
            }
        }
    }
    return false;
  }
  @Override
  public boolean evaluate(RowSet rs) {
    if (rs == null)
      return false;

    try {
      for (int i = 0; i < this.authors.length; i++) {
        String v = null;
        if (this.colNumber > 0) {
          v = (String)rs.getObject(this.colNumber);
        } else {
          return false;
        }
        if (v.equalsIgnoreCase(authors[i])) {
          return true;
        }
      }
    } catch (SQLException e) {
      return false;
    }
    return false;
  }
}

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