相关疑难解决方法(0)

我有ArrayList一些记录和一个列包含气体名称为CO2 CH4 SO2等.现在我想要检索不同的气体名称(唯一),只是没有重复ArrayList.怎么做到呢？

假设我有一个名为 MyClass 的类，如下所示：

public class MyClass
{
     //Identifier is alpha-numeric. If the identifier starts will 'ZZ'
     //is special special identifier.
     private String identifier = null;
     //Date string format YYYY-MM-DD
     private String dateString = null;
     //Just a flag (not important for this scenario)
     private boolean isCoolCat = false;
     //Default Constructor and getters/setters implemented
     //Overrides the standard Java equals() method.
     //This way, when ArrayList calls contains() for MyClass objects
     //it will only check the Date (for ZZ identifier) 
     //and identifier values against …