java - 从同一类中的另一个构造函数访问构造函数变量

Question

public GObject(Point3D[] v, Face[] f){
    vertex = v;
    face = f;
}

public GObject(String fileName){
    try{
           ...//read contents of file and store in an array
           Point3D[] vertices = new Point3D[numOfVertices];

    } catch(Exception e){
           System.out.println("Can't read file " + e.getMessage());
    }
}

第二个构造函数读取传递给它的文件，并且我已将这些值成功存储在顶点数组中，但是如何将顶点数组从第二个构造函数传递到第一个构造函数作为参数，以便 v = 顶点？

Answer 1

您需要使用这个 -

public GObject(String fileName){
    this(new Point3D[numOfVertices], new Face[5]); // `5` is just for example.

    try{
       ...//read contents of file and store in an array
       Point3D[] vertices = new Point3D[numOfVertices];

    } catch(Exception e){
       System.out.println("Can't read file " + e.getMessage());
    }
}

请注意，如果您使用此方法，则对 this 的调用必须是第二个构造函数的第一个语句。如果你很难遵守这个限制，那么我建议你这样做 -

public GObject(Point3D[] v, Face[] f){
    setV(v);
    face = f;
}

public GObject(String fileName){
    try{
       ...//read contents of file and store in an array
       setV(new Point3D[numOfVertices]);
    } catch(Exception e){
       System.out.println("Can't read file " + e.getMessage());
    }
}

private void setV(Point3D[] v) {
    vertex = v;
}

我认为第二种方法更好，因为它不会强制您仅仅为了调用另一个构造函数而构造一个 Face 数组。您还可以稍后更改设置逻辑或轻松合并验证。