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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997, 2015 Oracle and/or its affiliates. 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;
import java.nio.ByteBuffer;
class BulkAccessNIOExample {
private static final String FileName = "access.db";
public BulkAccessNIOExample() {
}
public static void main(String[] argv) {
try {
BulkAccessNIOExample app = new BulkAccessNIOExample();
app.run();
} catch (DatabaseException dbe) {
System.err.println("BulkAccessNIOExample: " + dbe.toString());
System.exit(1);
} catch (FileNotFoundException fnfe) {
System.err.println("BulkAccessNIOExample: " + fnfe.toString());
System.exit(1);
}
System.exit(0);
}
// 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() throws DatabaseException, FileNotFoundException {
// Remove the previous database.
new File(FileName).delete();
// Create the database object.
// There is no environment for this simple example.
DatabaseConfig config = new DatabaseConfig();
config.setErrorStream(System.err);
config.setErrorPrefix("BulkAccessNIOExample");
config.setType(DatabaseType.BTREE);
config.setAllowCreate(true);
config.setMode(0644);
Database table = new Database(FileName, null, config);
//
// 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 || (line.compareToIgnoreCase("end") == 0))
break;
String reversed = (new StringBuffer(line)).reverse().toString();
// See definition of StringEntry below
//
StringEntry key = new StringEntry(line, true);
StringEntry data = new StringEntry(reversed, true);
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 a cursor for the table.
Cursor cursor = table.openCursor(null, null);
DatabaseEntry foo = new DatabaseEntry();
MultipleKeyNIODataEntry bulk_data = new MultipleKeyNIODataEntry();
ByteBuffer rawData = ByteBuffer.allocateDirect(1024*1024);
bulk_data.setDataNIO(rawData);
bulk_data.setUserBuffer(1024 * 1024, true);
// Walk through the table, printing the key/data pairs.
//
while (cursor.getNext(foo, bulk_data, null) == OperationStatus.SUCCESS) {
StringEntry key, data;
key = new StringEntry();
data = new StringEntry();
while (bulk_data.next(key, data))
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 class StringEntry extends DatabaseEntry {
StringEntry() {
}
StringEntry(String value, boolean nioData) {
setString(value, nioData);
}
void setString(String value, boolean nioData) {
byte[] data = value.getBytes();
if(nioData) {
ByteBuffer newBuf = ByteBuffer.allocateDirect(data.length);
newBuf.position(0);
newBuf.put(data, 0, data.length);
newBuf.position(0);
setDataNIO(newBuf);
} else {
setData(data);
}
}
String getString() {
String ret;
if(getData() == null) {
ByteBuffer tmp = getDataNIO();
tmp.position(getOffset());
byte[] data = new byte[getSize()];
tmp.get(data, 0, getSize());
ret = new String(data, 0, getSize());
} else {
ret = new String(getData(), getOffset(), getSize());
}
return ret;
}
}
}
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