一个Woker类，当id和name相同时，系统判断两个工人是相等的，打印工人对象时显示“工人：id和name”。

public class Worker {
private int id;
        private String name;
         private double salary;
         public boolean equals(Object o){     
              boolean result = false;
              if(o== null){ result = false;
              }else{
                  if( o instanceof Worker) {
                      Worker temp = (Worker) o;
                      if(id == temp.id && name.equals(temp.name)){
                          result = true;
                    }else{
                     result = false;
                  }
                 }else{
                       result = false;
               }
}
 return result;
}
public String toString(){
        return id+name; 
     } 
}