Table creation/Postal addresses: Difference between revisions
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Of course J can connect external databases too, using e.g. [[j:Studio/ODBC%20Basics|ODBC]]. See the [[j:DB|list of J database topics]].
=={{header|Java}}==
Java can connect with many databases.
This example completes the task with a random access file, instead of using an external library.
<syntaxhighlight lang="java">
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
public final class TableCreationPostalAddresses {
public static void main(String[] args) throws IOException {
Path path = Path.of("addresses.dat");
Address[] addresses = new Address[] {
new Address("FSF Inc.", "51 Franklin Street", "Boston", "MA", "02110-1301"),
new Address("The White House", "1600 Pennsylvania Avenue NW", "Washington", "DC", "20500"),
new Address("National Security Council", "1700 Pennsylvania Avenue NW", "Washington", "DC", "20500")
};
FileChannel fileChannel = FileChannel.open(path, StandardOpenOption.CREATE,
StandardOpenOption.READ,
StandardOpenOption.WRITE);
for ( int i = 0; i < addresses.length; i++ ) {
byte[] data = addresses[i].addressRecord().getBytes();
ByteBuffer writeBuffer = ByteBuffer.wrap(data);
fileChannel.position(i * Address.RECORD_LENGTH);
while ( writeBuffer.hasRemaining() ) {
fileChannel.write(writeBuffer);
}
}
for ( int i = 0; i < addresses.length; i++ ) {
fileChannel.position(i * Address.RECORD_LENGTH);
ByteBuffer readBuffer = ByteBuffer.allocate(Address.RECORD_LENGTH);
fileChannel.read(readBuffer);
System.out.println( new String(readBuffer.array()) );
}
fileChannel.close();
}
}
final class Address {
public Address(String aName, String aStreet, String aCity, String aState, String aZipCode) {
name = aName; street = aStreet; city = aCity; state = aState; zipCode = aZipCode;
}
public String addressRecord() {
String record = "";
record += String.format("%-30s", name);
record += String.format("%-30s", street);
record += String.format("%-15s", city);
record += String.format("%-5s", state);
record += String.format("%-10s", zipCode);
return record;
}
public static final int RECORD_LENGTH = 30 + 30 + 15 + 5 + 10;
private String name, street, city, state, zipCode;
}
</syntaxhighlight>
{{ out }}
<pre>
FSF Inc. 51 Franklin Street Boston MA 02110-1301
The White House 1600 Pennsylvania Avenue NW Washington DC 20500
National Security Council 1700 Pennsylvania Avenue NW Washington DC 20500
</pre>
=={{header|Julia}}==
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