docs(java): add tip about java bigdecimal equals and compareTo

chenyong · chenyong · commit b94f83165b02 · 2021-05-08T18:54:27.000+08:00
diff --git a/java/basic/java-basic.md b/java/basic/java-basic.md
@@ -1578,4 +1578,7 @@ https://www.ibm.com/developerworks/cn/java/j-lo-javaio/index.html
 
 ## 面试题
 * Integer和int的区别
-* String a = new String("abc");共创建了几个对象
+* String a = new String("abc");共创建了几个对象
+
+## 注意点
+1. BigDecimal比较值，不要使用equals，因为0和0.00比较equals会判断false，要使用compareTo()。Compares this BigDecimal with the specified BigDecimal. Two BigDecimal objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method.
diff --git a/system/architecture/distribute_transactional.md b/system/architecture/distribute_transactional.md
@@ -0,0 +1,6 @@
+# 分布式事务
+
+### Seata
+https://www.oschina.net/p/seata?hmsr=aladdin1e1
+http://www.dreamwu.com/post-1741.html
+https://blog.csdn.net/hosaos/article/details/89136666
