PrintStream發生block現象

大概長得都如下:

"http-nio-38080-exec-32" #106 daemon prio=5 os_prio=0 tid=0x0000000025def800 
    nid=0x3164 waiting for monitor entry [0x000000003534a000]
   java.lang.Thread.State: BLOCKED (on object monitor)
	at java.io.PrintStream.println(PrintStream.java:805)
	- waiting to lock <0x00000006c0c70b10> (a java.io.PrintStream)
	at org.apache.ibatis.logging.stdout.StdOutImpl.debug(StdOutImpl.java:52)

這個錯誤絕大部分是由於控制檯打印出錯

請看:爲什麼不要用System.out.println()