所以，这是我的密码
因为某种原因它给了我

Vector.java:2: error: ';' expected
    public static void main(String[] args)
                                          ^
1 error

用分号，和

Vector.java:2: error: missing method body, or declare abstract
    public static void main(String[] args);
                       ^

没有它。我尝试了这两种变体，但编译器无论如何都不想这么做。有什么问题吗？我真的不明白

public class Vector {
    public static void main(String[] args);
  private final double x;
  private final double y;
  private final double z;

  public Vector(double x, double y, double z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }

public class CosineSimilarity extends AbstractSimilarity {

  @Override
  protected double computeSimilarity(Matrix sourceDoc, Matrix targetDoc) {
    double dotProduct = sourceDoc.arrayTimes(targetDoc).norm1();
    double eucledianDist = sourceDoc.normF() * targetDoc.normF();
    return dotProduct / eucledianDist;
  }}}