Algs4-1.2.14实现Transaction中的equals()方法

1.2.14用我们对Date中的equals()方法的实现(请见1.2.5.8节中的Date类代码框)作为模板，实现Transaction中的equals()方法。
答：

Code:
import java.util.Date;
public class Transaction
{
    private final String myWho;
    private final Date myWhen;
    private final double myAmount;
   
    public Transaction(String who,Date when,double amount)
    {
        myWho=who;
        myWhen=when;
        myAmount=amount;
      }
   
    public Transaction(String transaction)
    {
        String[] words=transaction.split("  ");
        myWho=words[0];
        myWhen=new Date(words[1]);
        myAmount=Double.parseDouble(words[2]);
    }
   
    public String who()
    {
        return myWho;
    }
   
    public Date when()
    {
        return myWhen;
    }
   
    public double amount()
    {
        return myAmount;
    }
   
    public boolean equals(Object x)
    {
        if(this==x) return true;
        if(x==null) return false;
        if(this.getClass()!=x.getClass())  return false;
        Transaction that=(Transaction) x;
        if(!this.myWho.equals(that.who())) return false;
        if(!this.myWhen.equals(that.when())) return false;
        if(this.myAmount!=that.amount()) return false;
        return true;
    }
    public static void main(String[] args)
    {
        Transaction t1=new Transaction("Jack",new Date("19/9/2016 13:00:00"),1000000);
        StdOut.printf("t1.who=%s,when=%s,amount=%.2f ",t1.who(),t1.when(),t1.amount());
       
        Transaction t2=new Transaction("LiLi  19/9/2016 13:25:00  1000002");
        StdOut.printf(" t2.who=%s,when=%s,amount=%.2f ",t2.who(),t2.when(),t2.amount());
       
        Transaction t3=new Transaction("Jack  19/9/2016 13:00:00  1000000");
        StdOut.printf(" t3.who=%s,when=%s,amount=%.2f ",t3.who(),t3.when(),t3.amount());
       
        StdOut.printf("t1=t2 is:%s ",t1.equals(t2));
        StdOut.printf("t1=t3 is:%s",t1.equals(t3));
    }
}