android--------解决Entities and POJOs must have a usable public constructor

　　　　　今天在学习android数据库，运行程序的时候报错，错误是：Entities and POJOs must have a usable public constructor. You can have an empty constructor or a constructor whose parameters match the fields (by name and type).Tried the following constructors but they failed to match:

Word(java.lang.String,java.lang.String) -> [param:english_word -> matched field:unmatched, param:chinese_meaning -> matched field:unmatched]。

　　　解决方法:在实体类写一个空的构造函数即可。

　　因为我有一个有参的构造函数，于是我写了一个空的构造函数即可运行。

　　

 

 　　写一个空的构造函数：

 

 

 

 

 

　　运行成功：