diff --git a/IP.java b/IP.java
index 548f0ed..d0b3a81 100644
--- a/IP.java
+++ b/IP.java
@@ -4,17 +4,40 @@
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Arrays;
+import java.nio.charset.Charset;
+import java.util.Random;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
 
 class IP {
 
+    public static String randomIp() {
+        Random r = new Random();
+        StringBuffer str = new StringBuffer();
+        str.append(r.nextInt(1000000) % 255);
+        str.append(".");
+        str.append(r.nextInt(1000000) % 255);
+        str.append(".");
+        str.append(r.nextInt(1000000) % 255);
+        str.append(".");
+        str.append(0);
+
+        return str.toString();
+    }
+
     public static void main(String[] args){
         IP.load("H:\\loveapp\\codebase\\17mon\\17monipdb.dat");
 
-        System.out.println(Arrays.toString(IP.find("8.8.8.8")));
-        System.out.println(Arrays.toString(IP.find("255.255.255.255")));
+        Long st = System.nanoTime();
+        for (int i = 0; i < 1000000; i++)
+        {
+            IP.find(randomIp());
+        }
+        Long et = System.nanoTime();
+        System.out.println((et - st) / 1000 / 1000);
+
+        System.out.println(Arrays.toString(IP.find("118.28.8.8")));
     }
 
     public static boolean enableFileWatch = false;
@@ -35,6 +58,20 @@ public static void load(String filename) {
         }
     }
 
+    public static void load(String filename, boolean strict) throws Exception {
+        ipFile = new File(filename);
+        if (strict) {
+            int contentLength = Long.valueOf(ipFile.length()).intValue();
+            if (contentLength < 512 * 1024) {
+                throw new Exception("ip data file error.");
+            }
+        }
+        load();
+        if (enableFileWatch) {
+            watch();
+        }
+    }
+
     public static String[] find(String ip) {
         int ip_prefix_value = new Integer(ip.substring(0, ip.indexOf(".")));
         long ip2long_value  = ip2long(ip);
@@ -52,6 +89,7 @@ public static String[] find(String ip) {
         }
 
         byte[] areaBytes;
+
         lock.lock();
         try {
             dataBuffer.position(offset + (int) index_offset - 1024);
@@ -61,7 +99,7 @@ public static String[] find(String ip) {
             lock.unlock();
         }
 
-        return new String(areaBytes).split("\t");
+        return new String(areaBytes, Charset.forName("UTF-8")).split("\t", -1);
     }
 
     private static void watch() {
@@ -104,13 +142,15 @@ private static void load() {
             }
             indexBuffer.order(ByteOrder.BIG_ENDIAN);
         } catch (IOException ioe) {
-
+            ioe.printStackTrace();
         } finally {
             try {
                 if (fin != null) {
                     fin.close();
                 }
-            } catch (IOException e){}
+            } catch (IOException e){
+                e.printStackTrace();
+            }
             lock.unlock();
         }
     }
@@ -140,4 +180,4 @@ private static long int2long(int i) {
         }
         return l;
     }
-}
\ No newline at end of file
+}
diff --git a/IPExt.java b/IPExt.java
index e0de74e..0ffc4ae 100644
--- a/IPExt.java
+++ b/IPExt.java
@@ -4,6 +4,7 @@
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.Arrays;
+import java.nio.charset.Charset;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
@@ -34,6 +35,20 @@ public static void load(String filename) {
             watch();
         }
     }
+    
+    public static void load(String filename, boolean strict) throws Exception {
+        ipFile = new File(filename);
+        if (strict) {
+            int contentLength = Long.valueOf(ipFile.length()).intValue();
+            if (contentLength < 512 * 1024) {
+                throw new Exception("ip data file error.");
+            }
+        }
+        load();
+        if (enableFileWatch) {
+            watch();
+        }
+    }
 
     public static String[] find(String ip) {
         String[] ips = ip.split("\\.");
@@ -49,7 +64,7 @@ public static String[] find(String ip) {
             tmpInt = int2long(indexBuffer.getInt(start));
             if (tmpInt >= ip2long_value) {
                 index_offset = bytesToLong(b, indexBuffer.get(start + 6), indexBuffer.get(start + 5), indexBuffer.get(start + 4));
-                index_length = (0xFF & indexBuffer.get(start + 7) << 8) + (0xFF & indexBuffer.get(start + 8));
+                index_length = ((0xFF & indexBuffer.get(start + 7)) << 8) + (0xFF & indexBuffer.get(start + 8));
                 break;
             }
         }
@@ -65,7 +80,7 @@ public static String[] find(String ip) {
             lock.unlock();
         }
 
-        return new String(areaBytes).split("\t");
+        return new String(areaBytes, Charset.forName("UTF-8")).split("\t", -1);
     }
 
     private static void watch() {
@@ -153,4 +168,4 @@ private static long int2long(int i) {
         }
         return l;
     }
-}
\ No newline at end of file
+}
diff --git a/README.md b/README.md
index 65a91ed..59e71a0 100644
--- a/README.md
+++ b/README.md
@@ -14,4 +14,11 @@ IP.find("8.8.8.8");//返回字符串数组["GOOGLE","GOOGLE"]
 
 ```
 
-IPExt的用法与IP的用法相同，只是用来解析datx格式文件。
\ No newline at end of file
+IPExt的用法与IP的用法相同，只是用来解析datx格式文件。
+
+##特别说明
+```java
+IP.java 类仅适用于免费版dat与收费版每周每日版本的dat文件；
+IPExt.java 类适用于收费版每日版本的datx文件；
+```
+区县库代码请查看 https://github.com/17mon/quxianku/