updated readme

Author: ankushs92

README.md

@@ -1 +1,39 @@
-Java wrapper for the DB-IP dataset
+# Java DB-IP
+A simple to use Java library for the freely available DB-IP [IP address to city dataset](https://db-ip.com/db/download/city).
+**Requires Java 8**
+
+#Before you begin
+The entire dataset is loaded into a [TreeMap](https://docs.oracle.com/javase/8/docs/api/allclasses-noframe.html) . Make sure that you have about **3 GB of Heap space** available to load it.
+
+
+#Instructions
+In order to get geographical information for an ip address, just pass the `dbip-city-latest.csv.gz` as a File object to `DbIpClient` as follows:
+
+```java
+File gzip = new File(PATH_TO_dbip-city-latest.csv.gz);
+DbIpClient client = new DbIpClient(gzip);
+```
+
+Once the data is loaded from the file into memory , any subsequent invocation of the above code **would not** re-load the data . 
+
+Next,just fetch the data for a ip ,like so :
+
+```java
+DbIpClient client = new DbIpClient(gzip);
+GeoEntity geoEntity = client.lookup("31.45.127.255");
+String city = geoEntity.getCity();
+String country = geoEntity.getCountry();
+String province = geoEntity.getProvince();
+
+System.out.println("city : " + city);
+System.out.println("province : " + province);
+System.out.println("country : " + country);
+```
+
+This prints : 
+```
+city : Oslo
+province : Oslo
+country : Norway
+```
+That's pretty much it.

src/main/java/in/ankushs/dbip/api/Test.java

@@ -7,13 +7,16 @@
 
 public class Test {
 	public static void main(String[] args) {
+		File gzip = new File("/Users/Ankush/Downloads/dbip-city-latest.csv.gz");
+		DbIpClient client = new DbIpClient(gzip);
+		GeoEntity geoEntity = client.lookup("31.45.127.255");
+		String city = geoEntity.getCity();
+		String country = geoEntity.getCountry();
+		String province = geoEntity.getProvince();
+		
+		System.out.println("city : " + city);
+		System.out.println("province : " + province);
+		System.out.println("country : " + country);
 
-
-		DbIpClient client = new DbIpClient(new File("/Users/Ankush/Downloads/dbip-city-latest.csv.gz"));
-		System.out.println(client.lookup("31.45.127.255"));
-		TreeMap<Integer,String> trees = new TreeMap<>();
-		trees.put(1,"a");
-		trees.put(1,"b");
-		System.out.println(trees);
-	}
+	} 
 }