Inserting records into Berkeley DB with Java
I can't seem to find sample code for constructing a Berkeley DB in Java and inserting records into it. Any samples? And I do not mean the Berkeley DB Java Edition either.
Answer
If you download db-5.0.21.NC.zip you will see plenty of samples. Here is one that seems to do what you want
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2004, 2010 Oracle and/or its affiliates. All rights reserved.
*
* $Id$
*/
// File: ExampleDatabaseLoad.java
package db.GettingStarted;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import java.util.Vector;
import com.sleepycat.bind.EntryBinding;
import com.sleepycat.bind.serial.SerialBinding;
import com.sleepycat.bind.tuple.TupleBinding;
import com.sleepycat.db.DatabaseEntry;
import com.sleepycat.db.DatabaseException;
public class ExampleDatabaseLoad {
private static String myDbsPath = "./";
private static File inventoryFile = new File("./inventory.txt");
private static File vendorsFile = new File("./vendors.txt");
// DatabaseEntries used for loading records
private static DatabaseEntry theKey = new DatabaseEntry();
private static DatabaseEntry theData = new DatabaseEntry();
// Encapsulates the databases.
private static MyDbs myDbs = new MyDbs();
private static void usage() {
System.out.println("ExampleDatabaseLoad [-h <database home>]");
System.out.println(" [-i <inventory file>] [-v <vendors file>]");
System.exit(-1);
}
public static void main(String args[]) {
ExampleDatabaseLoad edl = new ExampleDatabaseLoad();
try {
edl.run(args);
} catch (DatabaseException dbe) {
System.err.println("ExampleDatabaseLoad: " + dbe.toString());
dbe.printStackTrace();
} catch (Exception e) {
System.out.println("Exception: " + e.toString());
e.printStackTrace();
} finally {
myDbs.close();
}
System.out.println("All done.");
}
private void run(String args[])
throws DatabaseException {
// Parse the arguments list
parseArgs(args);
myDbs.setup(myDbsPath);
System.out.println("loading vendors db....");
loadVendorsDb();
System.out.println("loading inventory db....");
loadInventoryDb();
}
private void loadVendorsDb()
throws DatabaseException {
// loadFile opens a flat-text file that contains our data
// and loads it into a list for us to work with. The integer
// parameter represents the number of fields expected in the
// file.
List vendors = loadFile(vendorsFile, 8);
// Now load the data into the database. The vendor's name is the
// key, and the data is a Vendor class object.
// Need a serial binding for the data
EntryBinding dataBinding =
new SerialBinding(myDbs.getClassCatalog(), Vendor.class);
for (int i = 0; i < vendors.size(); i++) {
String[] sArray = (String[])vendors.get(i);
Vendor theVendor = new Vendor();
theVendor.setVendorName(sArray[0]);
theVendor.setAddress(sArray[1]);
theVendor.setCity(sArray[2]);
theVendor.setState(sArray[3]);
theVendor.setZipcode(sArray[4]);
theVendor.setBusinessPhoneNumber(sArray[5]);
theVendor.setRepName(sArray[6]);
theVendor.setRepPhoneNumber(sArray[7]);
// The key is the vendor's name.
// ASSUMES THE VENDOR'S NAME IS UNIQUE!
String vendorName = theVendor.getVendorName();
try {
theKey = new DatabaseEntry(vendorName.getBytes("UTF-8"));
} catch (IOException willNeverOccur) {}
// Convert the Vendor object to a DatabaseEntry object
// using our SerialBinding
dataBinding.objectToEntry(theVendor, theData);
// Put it in the database.
myDbs.getVendorDB().put(null, theKey, theData);
}
}
private void loadInventoryDb()
throws DatabaseException {
// loadFile opens a flat-text file that contains our data
// and loads it into a list for us to work with. The integer
// parameter represents the number of fields expected in the
// file.
List inventoryArray = loadFile(inventoryFile, 6);
// Now load the data into the database. The item's sku is the
// key, and the data is an Inventory class object.
// Need a tuple binding for the Inventory class.
TupleBinding inventoryBinding = new InventoryBinding();
for (int i = 0; i < inventoryArray.size(); i++) {
String[] sArray = (String[])inventoryArray.get(i);
String sku = sArray[1];
try {
theKey = new DatabaseEntry(sku.getBytes("UTF-8"));
} catch (IOException willNeverOccur) {}
Inventory theInventory = new Inventory();
theInventory.setItemName(sArray[0]);
theInventory.setSku(sArray[1]);
theInventory.setVendorPrice((new Float(sArray[2])).floatValue());
theInventory.setVendorInventory((new Integer(sArray[3])).intValue());
theInventory.setCategory(sArray[4]);
theInventory.setVendor(sArray[5]);
// Place the Vendor object on the DatabaseEntry object using our
// the tuple binding we implemented in InventoryBinding.java
inventoryBinding.objectToEntry(theInventory, theData);
// Put it in the database. Note that this causes our secondary database
// to be automatically updated for us.
myDbs.getInventoryDB().put(null, theKey, theData);
}
}
private static void parseArgs(String args[]) {
for(int i = 0; i < args.length; ++i) {
if (args[i].startsWith("-")) {
switch(args[i].charAt(1)) {
case 'h':
myDbsPath = new String(args[++i]);
break;
case 'i':
inventoryFile = new File(args[++i]);
break;
case 'v':
vendorsFile = new File(args[++i]);
break;
default:
usage();
}
}
}
}
private List loadFile(File theFile, int numFields) {
List records = new ArrayList();
try {
String theLine = null;
FileInputStream fis = new FileInputStream(theFile);
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
while((theLine=br.readLine()) != null) {
String[] theLineArray = splitString(theLine, "#");
if (theLineArray.length != numFields) {
System.out.println("Malformed line found in " + theFile.getPath());
System.out.println("Line was: '" + theLine);
System.out.println("length found was: " + theLineArray.length);
System.exit(-1);
}
records.add(theLineArray);
}
fis.close();
} catch (FileNotFoundException e) {
System.err.println(theFile.getPath() + " does not exist.");
e.printStackTrace();
usage();
} catch (IOException e) {
System.err.println("IO Exception: " + e.toString());
e.printStackTrace();
System.exit(-1);
}
return records;
}
private static String[] splitString(String s, String delimiter) {
Vector resultVector = new Vector();
StringTokenizer tokenizer = new StringTokenizer(s, delimiter);
while (tokenizer.hasMoreTokens())
resultVector.add(tokenizer.nextToken());
String[] resultArray = new String[resultVector.size()];
resultVector.copyInto(resultArray);
return resultArray;
}
protected ExampleDatabaseLoad() {}
}