java - java编译错误：找不到符号

Question

这是我的四门课：

J_Animal.java

package Animal;

public abstract class J_Animal
{
protected String name;
protected int age;
protected int weight;

public void showInfo()
{
    System.out.println("Name : " + this.name);
    System.out.println("Age : " + this.age);
    System.out.println("Weight : " + this.weight);
}

public abstract void move();
public abstract void eat();
}

J_Bird.java

package Animal;
import Animal.J_Animal;

public class J_Bird extends J_Animal
{
public J_Bird(String name, int age, int weight)
{
    this.name = name;
    this.age = age;
    this.weight = weight;
}

public void move()
{
    System.out.println("I'm a bird whose name is " + this.name + ". And I'm flying in the sky.");
}

public void eat()
{
    System.out.println("I'm a bird whose name is " + this.name + ". And I'm eating.");
}
}

J_Fish.java

package Animal;
import Animal.J_Animal;

public class J_Fish extends J_Animal
{
public J_Fish(String name, int age, int weight)
{
    this.name = name;
    this.age = age;
    this.weight = weight;
}

public void move()
{
    System.out.println("I'm a fish whose name is " + this.name + ". And I'm swimming in the water.");
}

public void eat()
{
    System.out.println("I'm a fish whose name is " + this.name + ". And I'm eating.");
}

}

J_Mammal.java

package Animal;
import Animal.J_Animal;

public class J_Mammal extends J_Animal
{
public J_Mammal(String name, int age, int weight)
{
    this.name = name;
    this.age = age;
    this.weight = weight;
}

public void move()
{
    System.out.println("I'm a mammal whose name is " + this.name + ". And I'm walking on the ground.");
}

public void eat()
{
    System.out.println("I'm a mammal whose name is " + this.name + ". And I'm eating.");
}
} 

我写了一个测试类来尝试一下。 J_TestAnimal.java

import Animal.*;

public class J_TestAnimal
{
public void TestForFish()
{
    //J_Animal testForAnimal = J_Animal("Joe" , 2, 10);
    J_Fish testForAnimal = J_Fish("Joe", 2, 10);
    testForAnimal.showInfo();
}

public static void main(String args[])
{
    J_TestAnimal j_test =new J_TestAnimal();
    j_test.TestForFish();
}
}

这是我的目录：C:\J_TestAnimal

\动物

 \J_Animal.class

 \J_Fish.class

 \J_Bird.class

 \J_Mammal.class

 \J_Animal.java

 \J_Fish.java

 \J_Bird.java

 \J_Mammal.java

\J_TestAnimal.java

当我运行命令“javac J_TestAnimal.java”时，出现错误“Cannot find the symbol”： J_TestAnimal.java:8: Error: Cannot find symbol

              J_Fish testForAnimal = J_Fish("Joe", 2, 10);

 Symbol : Method J_Fish(String, int, int)

 Position ： Class J_TestAnimal

Answer 1

使用new关键字创建一个J_Fish：

J_Fish testForAnimal = new J_Fish("Joe", 2, 10);