/*- * Copyright (c) 2002-2006 *	Oracle Corporation.  All rights reserved. * * $Id: second.javas,v 10.5 2006/08/24 16:32:26 bostic Exp $ */package db;import com.sleepycat.db.*;import java.io.File;import java.io.FileNotFoundException;import java.io.InputStreamReader;import java.io.IOException;import java.io.PrintStream;class SecondaryExample{	private static final String progname = "SecondaryExample";	private static final String DATABASE_HOME = "TESTDIR";	public static void main(String[] args)	{		try {			SecondaryExample app = new SecondaryExample();			app.run();		} catch(Exception e) {			System.err.println(progname + ": " + e);			e.printStackTrace(System.err);			System.exit(1);		}	}	void run() throws DbException, FileNotFoundException	{		DbEnv dbenv = new DbEnv(0);		/* Open the environment. */		dbenv.open(DATABASE_HOME,		    Db.DB_CREATE | Db.DB_INIT_LOCK | Db.DB_INIT_LOG |		    Db.DB_INIT_MPOOL | Db.DB_INIT_TXN, 0);		try {			run_app(dbenv);		} finally {			dbenv.close(0);		}	}	private void run_app(DbEnv dbenv)		throws DbException, FileNotFoundException	{		Db dbp, sdbp;		Dbt key, pkey, skey, data;		StudentRecord srec;		/* Open/create primary */		dbp = new Db(dbenv, 0);		dbp.open(null, "students.db", null, Db.DB_BTREE, Db.DB_CREATE,		    0600);		/*		 * Open/create secondary.  Note that it supports duplicate data		 * items, since last names might not be unique.		 */		sdbp = new Db(dbenv, 0);		sdbp.set_flags(Db.DB_DUP | Db.DB_DUPSORT);		sdbp.open(null, "lastname.db", null, Db.DB_BTREE, Db.DB_CREATE,		    0600);		try {			/* Associate the secondary with the primary. */			dbp.associate(sdbp, new GetName(), 0);			/* Add a new record */			key = new Dbt();			key.set_data("WC42".getBytes());			key.set_size(4);			srec = new StudentRecord();			srec.student_id = "WC42";			srec.last_name = "Churchill      ";			srec.first_name = "Winston        ";			data = new Dbt();			srec.encode(data);			System.out.println("Adding a record with primary key " +			    new String(key.get_data()) + " and secondary key " +			    srec.last_name);			dbp.put(null, key, data, 0);			/* Now do a lookup */			skey = new Dbt();			pkey = new Dbt();			data = new Dbt();			skey.set_data("Churchill      ".getBytes());			skey.set_size(15);			System.out.println("Searching with secondary key " +			    new String(skey.get_data()));			sdbp.pget(null, skey, pkey, data, 0);			System.out.println("Found a record with primary key " +			    new String(pkey.get_data()));		} finally {			dbp.close(0);			sdbp.close(0);		}	}	/*	 * getname -- extracts a secondary key (the last name) from a primary	 * 	key/data pair	 */	class GetName implements DbSecondaryKeyCreate {		public int secondary_key_create(Db secondary,		    Dbt pkey, Dbt pdata, Dbt skey) { 			StudentRecord srec = new StudentRecord();			srec.decode(pdata);			// Make a fixed-length array of last_name			byte[] last_name_data = srec.last_name.getBytes();			byte[] last_name_raw = new byte[15];			System.arraycopy(last_name_data, 0, last_name_raw, 0,			    last_name_data.length);			skey.set_data(last_name_raw);			skey.set_size(last_name_raw.length);			return (0);		}	}	class StudentRecord	{		String student_id;	// assumed to be 4 bytes long		String last_name;	// assumed to be 15 bytes long		String first_name;	// assumed to be 15 bytes long		void decode(Dbt dbt) {			byte[] data = dbt.get_data();			student_id = new String(data, 0, 4);			last_name = new String(data, 4, 15);			first_name = new String(data, 19, 15);		}		void encode(Dbt dbt) {			byte[] data = new byte[34];			System.arraycopy(student_id.getBytes(), 0, data, 0, 4);			byte[] last_name_raw = last_name.getBytes();			System.arraycopy(last_name_raw, 0, data, 4,			    last_name_raw.length);			byte[] first_name_raw = first_name.getBytes();			System.arraycopy(first_name_raw, 0, data, 19,			    first_name_raw.length);			dbt.set_data(data);			dbt.set_size(data.length);		}	}}