Package com.maxmind.geoip2

Class DatabaseReader

java.lang.Object
com.maxmind.geoip2.DatabaseReader
All Implemented Interfaces:
Closeable, AutoCloseable
public class DatabaseReader
extends Object
implements Closeable
Modified and simplified for I2P

The class DatabaseReader provides a reader for the GeoIP2 database format.

Usage

To use the database API, you must create a new DatabaseReader using the DatabaseReader.Builder. You must provide the Builder constructor either an InputStream or File for your GeoIP2 database. You may also specify the fileMode and the locales fallback order using the methods on the Builder object. After you have created the DatabaseReader, you may then call the appropriate method (e.g., city) for your database, passing it the IP address you want to look up.

If the lookup succeeds, the method call will return a response class for the GeoIP2 lookup. The class in turn contains multiple record classes, each of which represents part of the data returned by the database.

We recommend reusing the DatabaseReader object rather than creating a new one for each lookup. The creation of this object is relatively expensive as it must read in metadata for the file. It is safe to share the object across threads.

Caching

The database API supports pluggable caching (by default, no caching is performed). A simple implementation is provided by com.maxmind.db.CHMCache. Using this cache, lookup performance is significantly improved at the cost of a small (~2MB) memory overhead.

Since:
0.9.38

  • Method Details

    • close

      public void close() throws IOException

      Closes the database.

      If you are using FileMode.MEMORY_MAPPED, this will not unmap the underlying file due to a limitation in Java's MappedByteBuffer. It will however set the reference to the buffer to null, allowing the garbage collector to collect it.

      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException - if an I/O error occurs.

    • country

      public String country​(String ipAddress) throws IOException
      Throws:
      IOException

    • countryToIP

      public void countryToIP​(String country, Writer out) throws IOException
      I2P - Write all IPv4 address ranges for the given country to out.
      Parameters:
      country - two-letter case-insensitive
      out - caller must close
      Throws:
      IOException
      Since:
      0.9.48

    • getMetadata

      public Metadata getMetadata()
      Returns:
      the metadata for the open MaxMind DB file.

    • main

      public static void main​(String[] args) throws Exception
      Throws:
      Exception