我是java中的新继承人,我遇到了以下问题。我的基类是Plane,它的子类是PlaneComponent,PlaneComponent的子类是PassengerCompartment。我的课程由11个班级组成,当我忽略PassengerCompartment班级的权利时。但是当我运行整个程序时,我收到以下消息:at Plane.<init>(Plane.java:14) at PlaneComponent.<init>(PlaneComponent.java:1) at PassengerCompartment.<init>(PassengerCompartment.java:11)
这是反复打印很多次,我看不到错误的第一行。错误消息中包含的行是粗体行(这里在** **之间打印)。在java中使用继承时的错误消息
飞机:
import java.util.*;
public class Plane
{
int cap;
int pl;
public Plane()
{
String desc = "Plane Description";
String title = "Boeing 747";
Random rand = new Random();
cap = rand.nextInt(100) + 51; //initialize cap with 50<value<100
**PassengerCompartment a8 = new PassengerCompartment();**
pl = cap/a8.cap2; // pl = sum of Passenger Compartments
if (cap % a8.cap2 != 0)
{
pl = pl - (cap % a8.cap2) + 1;
}
}
public boolean ready_check()
{
CargoBay a6 = new CargoBay();
a6.ready_check();
for (int i = 0 ; i < 3 ; i++)
{
EquipmentCompartment a7 = new EquipmentCompartment();
a7.ready_check();
}
for(int i = 0; i < pl; i++)
{
PassengerCompartment a8 = new PassengerCompartment();
a8.ready_check();
}
System.out.println("Plane OK!");
return true;
}
public void process(String e)
{
if(e == "SecurityEmployee")
{
SecurityEmployee a14 = new SecurityEmployee();
a14.workOn();
}
if(e == "MaintenanceEmployee")
{
MaintenanceEmployee a15 = new MaintenanceEmployee();
a15.workOn();
}
if(e == "CleaningEmployee")
{
CleaningEmployee a16 = new CleaningEmployee();
a16.workOn();
}
}
public void values()
{
System.out.println("Would you like more info about the plane's capacity? type Y or N");
Scanner input = new Scanner(System.in);
String inp = input.nextLine();
while (!(inp.equals("Y")) && !(inp.equals("N")))
{
System.out.println("Wrong input, please type again");
inp = input.nextLine();
}
if (inp.equals("Y"))
{
PassengerCompartment a8 = new PassengerCompartment();
System.out.println("Plane's capacity: " + cap);
System.out.println("PassComp's capacity: " + a8.cap2);
System.out.println("Number ofPassenger Compartments " + pl);
}
}
}
PlaneComponent:
**public class PlaneComponent extends Plane**
{
public boolean ready_check()
{
return true;
}
public void process(String desc)
{
Employee.workOn(desc);
}
}
PassengerCompartment:
import java.util.*;
public class PassengerCompartment extends PlaneComponent
{
Random rand = new Random();
boolean inner = rand.nextBoolean();
int cap2;
String desc;
public PassengerCompartment()
**{**
desc = "Passenger Compartment";
cap2 = rand.nextInt(50) + 21; //initialize cap with 20<value<50
}
public boolean ready_check()
{
System.out.println(desc);
if (super.ready_check() == true)
{
System.out.println("Passenger Compartment OK!");
if (inner == true)
{
desc = "Inner Compartment";
System.out.println(desc);
if (super.ready_check() == true)
{
System.out.println("Inner Compartment OK!");
}
}
}
return true;
}
public void process(String desc)
{
super.process(desc);
}
}
这个错误信息打印了很多次,我看不到第一行stacktrace。你能帮我找到一种方法来查看整个堆栈跟踪吗? –
另外,在比较字符串时,使用等号方法 示例e.equals(“SecurityEmployee”) –
不需要'== true',只需使用if(bool)'。 – Idos