将HashMap转换为ArrayList [英] Converting HashMap to ArrayList

问题描述

  HashMap< String，ExceptionLifeCycleDataBean>< p> transitionHash = new HashMap< String，ExceptionLifeCycleDataBean>（）; 
 
 ArrayList< ExceptionLifeCycleDataBean> cardholderDataRecords = new ArrayList< ExceptionLifeCycleDataBean>（）; 
  

我做的是

  cardholderDataRecords.add（（ExceptionLifeCycleDataBean）transitionHash.values（））; 
  

投掷

  java.lang.ClassCastException：java.util.HashMap $ Values不能转换为com.reportss.bean.ExceptionLifeCycleDataBean 
  

解决方案

您试图将值集合转换为单个 ExceptionLifeCycleDataBean



你可以很容易的得到这个列表：

 列表与LT; ExceptionLifeCycleDataBean> beans = 
 new ArrayList< ExceptionLifeCycleDataBean>（transitionHash.values（））; 
  

或者添加到现有集合中：



  cardholderDataRecords.addAll（transitionHash.values（））; 
  

不需要转换。


I just want to move the transitionHash map values into the cardholderDataRecords arraylist.

HashMap<String,ExceptionLifeCycleDataBean> transitionHash = new HashMap<String,ExceptionLifeCycleDataBean>();

ArrayList<ExceptionLifeCycleDataBean> cardholderDataRecords = new ArrayList<ExceptionLifeCycleDataBean>();

i am doing as

cardholderDataRecords.add((ExceptionLifeCycleDataBean) transitionHash.values());

It's throwing

java.lang.ClassCastException: java.util.HashMap$Values cannot be cast to com.reportss.bean.ExceptionLifeCycleDataBean

解决方案

You're trying to cast the collection of values to a single ExceptionLifeCycleDataBean.

You can very easily get the list though:

List<ExceptionLifeCycleDataBean> beans =
    new ArrayList<ExceptionLifeCycleDataBean>(transitionHash.values());

Or to add to an existing collection, with:

cardholderDataRecords.addAll(transitionHash.values());

No casts necessary.

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