fixed #191 Using IP lowest bit to generate worker id

Author: gaohongtao

sharding-jdbc-doc/content/post/release_notes.md

@@ -8,6 +8,11 @@ weight = 1
 
 ## 1.4.1-SNAPSHOT
 
+### 功能提升
+
+1. [ISSUE #191](https://github.com/dangdangdotcom/sharding-jdbc/issues/191) 根据主机的IP生成workerId的IdGenerator实现
+1. [ISSUE #192](https://github.com/dangdangdotcom/sharding-jdbc/issues/192) 根据HOSTNAME的数字尾缀获取workerId的IdGenerator
+
 ### 缺陷修正
 
 1. [ISSUE #194](https://github.com/dangdangdotcom/sharding-jdbc/issues/194) jdbc接口中资源释放错误

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/src/main/java/com/dangdang/ddframe/rdb/sharding/id/generator/self/CommonSelfIdGenerator.java

@@ -112,6 +112,15 @@ public static void setWorkerId(final Long workerId) {
         CommonSelfIdGenerator.workerId = workerId;
     }
 
+    /**
+     * 获取工作Id的二进制长度.
+     * 
+     * @return 工作Id的二进制长度
+     */
+    public static long getWorkerIdLength() {
+        return WORKER_ID_BITS;
+    }
+    
     /**
      * 生成Id.
      * 

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/src/main/java/com/dangdang/ddframe/rdb/sharding/id/generator/self/IPIdGenerator.java

@@ -23,9 +23,9 @@
 import java.net.UnknownHostException;
 
 /**
- * 根据机器IP获取工作进程Id，如果线上机器的IP二进制表示的最后10位不重复，建议使用此种方式
- * ，列如机器的IP为192.168.1.108，二进制表示：11000000 10101000 00000001 01101100
- * ，截取最后10位 01 01101100，转为十进制364，设置workerId为364
+ * 根据机器IP获取工作进程Id,如果线上机器的IP二进制表示的最后10位不重复,建议使用此种方式
+ * ,列如机器的IP为192.168.1.108,二进制表示:11000000 10101000 00000001 01101100
+ * ,截取最后10位 01 01101100,转为十进制364,设置workerId为364.
  *
  * @author DonneyYoung
  */
@@ -39,15 +39,13 @@ public class IPIdGenerator implements IdGenerator {
 
     static void initWorkerId() {
         InetAddress address;
-        Long workerId;
         try {
             address = InetAddress.getLocalHost();
-        } catch (UnknownHostException e) {
+        } catch (final UnknownHostException e) {
             throw new IllegalStateException("Cannot get LocalHost InetAddress, please check your network!");
         }
-        String[] ipAddress = address.getHostAddress().split("\\.");
-        workerId = ((Long.valueOf(ipAddress[ipAddress.length - 2]) & 0b11) << 8) + Long.valueOf(ipAddress[ipAddress.length - 1]);
-        CommonSelfIdGenerator.setWorkerId(workerId);
+        byte[] ipAddressByteArray = address.getAddress();
+        CommonSelfIdGenerator.setWorkerId((long) (((ipAddressByteArray[ipAddressByteArray.length - 2] & 0B11) << Byte.SIZE) + (ipAddressByteArray[ipAddressByteArray.length - 1] & 0xFF)));
     }
 
     @Override