在Java程序中找不到符号

Question

因此，这里的困境： 我正在编写一个程序，使用两个不同的类，使用两个不同的包。然而，当我尝试从BaseGame调用一个方法（该方法与类）。我检查了拼写，我只是困惑。

下面的代码：

从Automobile.java：

package mygame.model; 

import com.jme3.bullet.BulletAppState; 
import com.jme3.app.SimpleApplication; 
import com.jme3.bounding.BoundingBox; 
import com.jme3.bullet.PhysicsSpace; 
import com.jme3.bullet.collision.shapes.CollisionShape; 
import com.jme3.bullet.collision.shapes.MeshCollisionShape; 
import com.jme3.bullet.control.VehicleControl; 
import com.jme3.bullet.nodes.PhysicsNode; 
import com.jme3.bullet.objects.VehicleWheel; 
import com.jme3.bullet.util.CollisionShapeFactory; 
import com.jme3.input.KeyInput; 
import com.jme3.input.controls.ActionListener; 
import com.jme3.input.controls.KeyTrigger; 
import com.jme3.light.DirectionalLight; 
import com.jme3.material.Material; 
import com.jme3.math.FastMath; 
import com.jme3.math.Matrix3f; 
import com.jme3.math.Vector2f; 
import com.jme3.math.Vector3f; 
import com.jme3.renderer.queue.RenderQueue.ShadowMode; 
import com.jme3.scene.Geometry; 
import com.jme3.scene.Node; 
import com.jme3.scene.Spatial; 
import com.jme3.scene.shape.Box; 
import com.jme3.shadow.BasicShadowRenderer; 
import com.jme3.texture.Texture.WrapMode; 
import mygame.BaseGame; 

public class Automobile extends Model { 
    float stiffness; 
    float compValue; 
    float dampValue; 
    float mass; 
    Node node; 
    VehicleControl vehicle; 
    float wheelRadius; 

    // <editor-fold defaultstate="collapsed" desc="findGeom"> 
private Geometry findGeom(Spatial spatial, String name) { 
    if (spatial instanceof Node) { 
     Node node = (Node) spatial; 
     for (int i = 0; i < node.getQuantity(); i++) { 
      Spatial child = node.getChild(i); 
      Geometry result = findGeom(child, name); 
      if (result != null) { 
       return result; 
      } 
     } 
    } else if (spatial instanceof Geometry) { 
     if (spatial.getName().startsWith(name)) { 
      return (Geometry) spatial; 
     } 
    } 
    return null; 
}// </editor-fold> 
    private void buildVehicle() { 
    //Load model and get chassis Geometry 
    node = (Node)loadModel("Models/Ferrari/Car.scene"); 
    node.setShadowMode(ShadowMode.Cast); 
    Geometry chasis = findGeom(node, "Car"); 
    BoundingBox box = (BoundingBox) chasis.getModelBound(); 

    //Create a hull collision shape for the chassis 
    CollisionShape carHull = CollisionShapeFactory.createDynamicMeshShape(chasis); 

    //Create a vehicle control 
    vehicle = new VehicleControl(carHull, mass); 
    node.addControl(vehicle); 

    //Setting default values for wheels 
    vehicle.setSuspensionCompression(compValue * 2.0f * FastMath.sqrt(stiffness)); 
    vehicle.setSuspensionDamping(dampValue * 2.0f * FastMath.sqrt(stiffness)); 
    vehicle.setSuspensionStiffness(stiffness); 
    vehicle.setMaxSuspensionForce(10000); 

    //Create four wheels and add them at their locations 
    //note that our fancy car actually goes backwards.. 
    Vector3f wheelDirection = new Vector3f(0, 1, 0); 
    Vector3f wheelAxle = new Vector3f(-1, 0, 0); 

    Geometry wheel_fr = findGeom(node, "WheelFrontRight"); 
    wheel_fr.center(); 
    box = (BoundingBox) wheel_fr.getModelBound(); 
    wheelRadius = box.getYExtent(); 
    float back_wheel_h = (wheelRadius * 1.7f) - 1f; 
    float front_wheel_h = (wheelRadius * 1.9f) - 1f; 
    vehicle.addWheel(wheel_fr.getParent(), box.getCenter().add(0, -front_wheel_h, 0), 
      wheelDirection, wheelAxle, 0.2f, wheelRadius, true); 

    Geometry wheel_fl = findGeom(node, "WheelFrontLeft"); 
    wheel_fl.center(); 
    box = (BoundingBox) wheel_fl.getModelBound(); 
    vehicle.addWheel(wheel_fl.getParent(), box.getCenter().add(0, -front_wheel_h, 0), 
      wheelDirection, wheelAxle, 0.2f, wheelRadius, true); 

    Geometry wheel_br = findGeom(node, "WheelBackRight"); 
    wheel_br.center(); 
    box = (BoundingBox) wheel_br.getModelBound(); 
    vehicle.addWheel(wheel_br.getParent(), box.getCenter().add(0, -back_wheel_h, 0), 
      wheelDirection, wheelAxle, 0.2f, wheelRadius, false); 

    Geometry wheel_bl = findGeom(node, "WheelBackLeft"); 
    wheel_bl.center(); 
    box = (BoundingBox) wheel_bl.getModelBound(); 
    vehicle.addWheel(wheel_bl.getParent(), box.getCenter().add(0, -back_wheel_h, 0), 
      wheelDirection, wheelAxle, 0.2f, wheelRadius, false); 

    vehicle.getWheel(2).setFrictionSlip(4); 
    vehicle.getWheel(3).setFrictionSlip(4); 

} 
public Automobile(Spatial sp){ 
    super(sp); 
} 
} 

从BaseGame.java

package mygame; 

import com.jme3.app.SimpleApplication; 
import com.jme3.asset.AssetManager; 
import com.jme3.export.JmeExporter; 
import com.jme3.export.JmeImporter; 
import com.jme3.export.Savable; 
import com.jme3.material.Material; 
import com.jme3.math.ColorRGBA; 
import com.jme3.math.Vector3f; 
import com.jme3.renderer.RenderManager; 
import com.jme3.scene.Geometry; 
import com.jme3.scene.Spatial; 
import com.jme3.scene.shape.Box; 
import java.io.IOException; 

public class BaseGame extends SimpleApplication{ 

public static void main(String[] args) { 
    BaseGame app = new BaseGame(); 
    app.start(); 
} 
public Spatial loadModel(String asset){ 
    return assetManager.loadModel(asset); 
} 
@Override 
public void simpleInitApp() { 

} 

@Override 
public void simpleUpdate(float tpf) { 
    //TODO: add update code 
} 

@Override 
public void simpleRender(RenderManager rm) { 
    //TODO: add render code 
} 

} 

*编辑 这里的错误：

E:\Game\BasicGame\src\mygame\model\Automobile.java:64: cannot find symbol 
symbol : method loadModel(java.lang.String) 
location: class mygame.model.Automobile 
    node = (Node)loadModel("Models/Ferrari/Car.scene"); 

而且，我确实导入了这个类。

Answer 1

loadModel是一种非静态方法。您需要从类的 对象 实例中调用它。

而且，即使它是一个静态方法，你应该从它的类调用它，例如BaseGame.loadModel("somestring");

后您编辑你的答案，我认为这是明确的问题：

• 你实例化一个BaseGame对象，主要（BaseGame app = new BaseGame();），但你似乎没有实现任何特殊的东西。
• 你有一个单独的类，在一个单独的包中，它没有提到BaseGame实例，因为没有人通过这样的引用，并且import是而不是的一个实例。