抽象对象如何存入list java

刺骨的言语ヽ痛彻心扉 2023-09-24 17:47 49阅读 0赞

> 使用 ArrayList将抽象继承后的对象放入list中

ArrayList<AbstractExpression> list = new ArrayList<AbstractExpression>(2);
            AbstractExpression t = new TerminalExpression();
            AbstractExpression n = new NonterminalExpression();
            list.add(t);
            list.add(n);

# 代码 #

abstract class AbstractExpression {
        
        abstract void interpret(Context context);
    }

public class TerminalExpression extends AbstractExpression{
        
        @Override
        void interpret(Context context) {
        
            System.out.println("TerminalExpression");
        }
    }

public class NonterminalExpression extends AbstractExpression{
        
        @Override
        void interpret(Context context) {
        
            System.out.println("NonterminalExpression");
        }
    }

public class Context {
        
        private String input;
        private String output;
    
        public String getInput() {
        
            return input;
        }
    
        public void setInput(String input) {
        
            this.input = input;
        }
    
        public String getOutput() {
        
            return output;
        }
    
        public void setOutput(String output) {
        
            this.output = output;
        }
    }

public class Client {
        
        public static void main(String[] args) {
        
            Context context = new Context();
            ArrayList<AbstractExpression> list = new ArrayList<AbstractExpression>(2);//使用 ArrayList将抽象继承后的对象放入list中
            AbstractExpression t = new TerminalExpression();
            AbstractExpression n = new NonterminalExpression();
            list.add(t);
            list.add(n);
            for (AbstractExpression data : list) {
        
                data.interpret(context);
            }
        }
    }

# 运行结果 #

TerminalExpression
    NonterminalExpression