出乎意料的是，我开始在cassandra的datastax驱动程序3.2版中得到一个nullpointerexception
我真的不明白发生了什么事。同样的查询似乎在99%的情况下都有效，但偶尔我会发现：

java.lang.NullPointerException: Parameter value cannot be null
    at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:228)
    at com.datastax.driver.core.CodecRegistry.findCodec(CodecRegistry.java:524)
    at com.datastax.driver.core.CodecRegistry.maybeCreateCodec(CodecRegistry.java:642)
    at com.datastax.driver.core.CodecRegistry.createCodec(CodecRegistry.java:550)
    at com.datastax.driver.core.CodecRegistry.findCodec(CodecRegistry.java:532)
    at com.datastax.driver.core.CodecRegistry.codecFor(CodecRegistry.java:407)
    at com.datastax.driver.core.querybuilder.Utils.appendValue(Utils.java:98)
    at com.datastax.driver.core.querybuilder.Assignment$SetAssignment.appendTo(Assignment.java:57)
    at com.datastax.driver.core.querybuilder.Utils.joinAndAppend(Utils.java:44)
    at com.datastax.driver.core.querybuilder.Update.buildQueryString(Update.java:73)
    at com.datastax.driver.core.querybuilder.BuiltStatement.toString(BuiltStatement.java:295)
    at com.datastax.driver.core.querybuilder.BuiltStatement$ForwardingStatement.toString(BuiltStatement.java:446)
    at com.datastax.driver.core.querybuilder.Update$Where.toString(Update.java:227)
    at ....my code here

你知道发生了什么事吗？
谢谢！