使用时出错菲尔纳测向仪(0)

Question

使用spark+python的非常简单的代码：

df = spark.read.option("header","true").csv(file_name)
df = df_abnor_matrix.fillna(0)

但出现错误：

pyspark.sql.utils.AnalysisException: u'Cannot resolve column name "cp_com.game.shns.uc" among (ProductVersion, IMEI, FROMTIME, TOTIME, STATISTICTIME, TimeStamp, label, MD5, cp_com.game.shns.uc, cp_com.yunchang....

怎么了？cp_com.game.shns.uc在列表中。你知道吗

Answer 1

这是因为mDetailFragment没有初始化

堆栈跟踪显示mDetailFragment=null

java.lang.NullPointerException: Attempt to invoke virtual method 'void com.example.rssreader.Controllers.Fragments.DetailFragment.setTitle(java.lang.String)' on a null

基本上你需要做的就是

// Let's first dynamically add a fragment into a frame container, that is your xml like a LinearLayout
         getSupportFragmentManager().beginTransaction(). 
             replace(R.id.YOUR_XML, new DetailFragment(), "SOMETAG").
             commit();
         // Now later we can lookup the fragment by tag
         DetailFragment mDetailFragment = (DetailFragment) 
             getSupportFragmentManager().findFragmentByTag("SOMETAG");

要使用片段，本教程介绍了几种方法 Creating and Using Fragments

UPDATE

将onCreate()更改为以下内容：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_detail);
    Intent intent = getIntent();
    Bundle bundle = intent.getExtras();
    DetailFragment fragment = (DetailFragment)getSupportFragmentManager().findFragmentByTag("TAG");
    if(fragment == NULL){
        fragment = DetailFragment.newInstance();
    }
    fragment.setTitle((String) bundle.get("setTitle"));
    startTransactionFragment(fragment);
}

我没有测试代码，只是从头开始