DatabaseReader (I2P Anonymous Network - Java Documentation - Version 1.5.0)

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

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class DatabaseReader.Builder
Constructs a Builder for the DatabaseReader.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes the database.
`String`	`country(String ipAddress)`
`void`	`countryToIP(String country, Writer out)`	I2P - Write all IPv4 address ranges for the given country to out.
`Metadata`	`getMetadata()`
`static void`	`main(String[] args)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - 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