增加crc

app/src/main/java/com/xuj/MainActivity.java

@@ -32,7 +32,7 @@ protected void onCreate(Bundle savedInstanceState) {
 
         List<KvEntity> kventity = da.query(tableName, " * ", "", null, null, KvEntity.class);
         for (KvEntity entity : kventity) {
-            Log.e("TAG", "onCreate: " + entity + toString());
+            Log.e("TAG", "onCreate: " + entity.toString());
         }
 
         //执行sql语句

xujlibrary/src/main/java/com/xuj/lib/CrcTool.java

@@ -0,0 +1,34 @@
+package com.xuj.lib;
+
+public class CrcTool {
+
+
+    public static byte getCrcLow(byte[] body) {
+        byte crcLow = getCrc(body)[1];
+        return crcLow;
+    }
+
+    public static byte[] getCrc(byte[] body) {
+        int i = CRC16_XMODEM(body);
+        byte[] bytes1 = TextHelper.intToByte2(i);
+        return bytes1;
+    }
+
+
+    public static int CRC16_XMODEM(byte[] buffer) {
+        int wCRCin = 0x0000; // initial value 65535
+        int wCPoly = 0x1021; // 0001 0000 0010 0001 (0, 5, 12)
+        for (byte b : buffer) {
+            for (int i = 0; i < 8; i++) {
+                boolean bit = ((b >> (7 - i) & 1) == 1);
+                boolean c15 = ((wCRCin >> 15 & 1) == 1);
+                wCRCin <<= 1;
+                if (c15 ^ bit)
+                    wCRCin ^= wCPoly;
+            }
+        }
+        wCRCin &= 0xffff;
+        return wCRCin ^= 0x0000;
+    }
+
+}

xujlibrary/src/main/java/com/xuj/lib/TextHelper.java

@@ -126,6 +126,12 @@ public static String byteToHexStringAddSpace(byte[] bArray) {
 		return sb.toString();
 	}
 
+
+	public static byte[] intToByte2LH(int i) {
+		byte[] bytes = intToByte2(i);
+		byte[] re=new byte[]{bytes[1],bytes[0]};
+		return re;
+	}
 	/**
 	 *hexstr转字节数组
 	 */