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+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1997-2009 Oracle. All rights reserved.
+ *
+ * $Id$
+ */
+
+
+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 AccessExample {
+ private static final int EXIT_SUCCESS = 0;
+ private static final int EXIT_FAILURE = 1;
+
+ public AccessExample() {
+ }
+
+ public static void usage() {
+ System.out.println("usage: java " +
+ "db.AccessExample [-r] [database]\n");
+ System.exit(EXIT_FAILURE);
+ }
+
+ public static void main(String[] argv) {
+ boolean removeExistingDatabase = false;
+ String databaseName = "access.db";
+
+ for (int i = 0; i < argv.length; i++) {
+ if (argv[i].equals("-r"))
+ removeExistingDatabase = true;
+ else if (argv[i].equals("-?"))
+ usage();
+ else if (argv[i].startsWith("-"))
+ usage();
+ else {
+ if ((argv.length - i) != 1)
+ usage();
+ databaseName = argv[i];
+ break;
+ }
+ }
+
+ try {
+ AccessExample app = new AccessExample();
+ app.run(removeExistingDatabase, databaseName);
+ } catch (DatabaseException dbe) {
+ System.err.println("AccessExample: " + dbe.toString());
+ System.exit(EXIT_FAILURE);
+ } catch (FileNotFoundException fnfe) {
+ System.err.println("AccessExample: " + fnfe.toString());
+ System.exit(EXIT_FAILURE);
+ }
+ System.exit(EXIT_SUCCESS);
+ }
+
+ // Prompts for a line, and keeps prompting until a non blank
+ // line is returned. Returns null on error.
+ //
+ public static String askForLine(InputStreamReader reader,
+ PrintStream out, String prompt) {
+ String result = "";
+ while (result != null && result.length() == 0) {
+ out.print(prompt);
+ out.flush();
+ result = getLine(reader);
+ }
+ return result;
+ }
+
+ // Not terribly efficient, but does the job.
+ // Works for reading a line from stdin or a file.
+ // Returns null on EOF. If EOF appears in the middle
+ // of a line, returns that line, then null on next call.
+ //
+ public static String getLine(InputStreamReader reader) {
+ StringBuffer b = new StringBuffer();
+ int c;
+ try {
+ while ((c = reader.read()) != -1 && c != '\n') {
+ if (c != '\r')
+ b.append((char)c);
+ }
+ } catch (IOException ioe) {
+ c = -1;
+ }
+
+ if (c == -1 && b.length() == 0)
+ return null;
+ else
+ return b.toString();
+ }
+
+ public void run(boolean removeExistingDatabase, String databaseName)
+ throws DatabaseException, FileNotFoundException {
+
+ // Remove the previous database.
+ if (removeExistingDatabase)
+ new File(databaseName).delete();
+
+ // Create the database object.
+ // There is no environment for this simple example.
+ DatabaseConfig dbConfig = new DatabaseConfig();
+ dbConfig.setErrorStream(System.err);
+ dbConfig.setErrorPrefix("AccessExample");
+ dbConfig.setType(DatabaseType.BTREE);
+ dbConfig.setAllowCreate(true);
+ Database table = new Database(databaseName, null, dbConfig);
+
+ //
+ // Insert records into the database, where the key is the user
+ // input and the data is the user input in reverse order.
+ //
+ InputStreamReader reader = new InputStreamReader(System.in);
+
+ for (;;) {
+ String line = askForLine(reader, System.out, "input> ");
+ if (line == null)
+ break;
+
+ String reversed = (new StringBuffer(line)).reverse().toString();
+
+ // See definition of StringDbt below
+ //
+ StringEntry key = new StringEntry(line);
+ StringEntry data = new StringEntry(reversed);
+
+ try {
+ if (table.putNoOverwrite(null, key, data) == OperationStatus.KEYEXIST)
+ System.out.println("Key " + line + " already exists.");
+ } catch (DatabaseException dbe) {
+ System.out.println(dbe.toString());
+ }
+ }
+
+ // Acquire an iterator for the table.
+ Cursor cursor;
+ cursor = table.openCursor(null, null);
+
+ // Walk through the table, printing the key/data pairs.
+ // See class StringDbt defined below.
+ //
+ StringEntry key = new StringEntry();
+ StringEntry data = new StringEntry();
+ while (cursor.getNext(key, data, null) == OperationStatus.SUCCESS)
+ System.out.println(key.getString() + " : " + data.getString());
+ cursor.close();
+ table.close();
+ }
+
+ // Here's an example of how you can extend DatabaseEntry in a
+ // straightforward way to allow easy storage/retrieval of strings,
+ // or whatever kind of data you wish. We've declared it as a static
+ // inner class, but it need not be.
+ //
+ static /*inner*/
+ class StringEntry extends DatabaseEntry {
+ StringEntry() {
+ }
+
+ StringEntry(String value) {
+ setString(value);
+ }
+
+ void setString(String value) {
+ byte[] data = value.getBytes();
+ setData(data);
+ setSize(data.length);
+ }
+
+ String getString() {
+ return new String(getData(), getOffset(), getSize());
+ }
+ }
+}