SQL Batch
/* Database Programming with JDBC and Java, Second Edition By George Reese ISBN: 1-56592-616-1 Publisher: O'Reilly */import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.Iterator; /** * Example 4.1. */publicclass Batch { staticpublicvoid main(String[] args) { Connection conn = null; try { ArrayList breakable = new ArrayList(); PreparedStatement stmt; Iterator users; ResultSet rs; Class.forName(args[0]).newInstance(); conn = DriverManager.getConnection(args[1], args[2], args[3]); stmt = conn.prepareStatement("SELECT user_id, password " + "FROM user"); rs = stmt.executeQuery(); while (rs.next()) { String uid = rs.getString(1); String pw = rs.getString(2); // Assume PasswordCracker is some class that provides // a single static method called crack() that attempts // to run password cracking routines on the password // if( PasswordCracker.crack(uid, pw) ) { // breakable.add(uid); // } } stmt.close(); if (breakable.size() < 1) { return; } stmt = conn.prepareStatement("UPDATE user " + "SET bad_password = 'Y' " + "WHERE uid = ?"); users = breakable.iterator(); while (users.hasNext()) { String uid = (String) users.next(); stmt.setString(1, uid); stmt.addBatch(); } stmt.executeBatch(); } catch (Exception e) { e.printStackTrace(); } finally { if (conn != null) { try { conn.close(); } catch (Exception e) { } } } } } Related examples in the same category
