java - 当字符串形状非法时抛出异常

Question

我在代码中对 Excetpion 做了一些错误的事情，因为当 String 布局 时，例如:

..b.
bbb.     //<---Illegal

...
.x.
...      //<---Illegal

..r
.rr      //<---Illegal

.....
.y...
..y..
...y.    //<---Illegal

被传递到方法中(一次只能传递一个布局)，该方法应该抛出异常，因为形状的字符串布局必须在每个布局中至少有一个填充 block 第 0 行、第 0 列、最后一行 和最后一列。以下字符串布局是合法的:

...e
..e.
e...

a...a
.....
.....
a....

我的代码仅在看到第一行的第一个和最后一个字符时处理异常。 smb 可以帮我解决一下关于抛出异常的方法吗？预先感谢!

public static Shape makeShape(String layout,char displayChar)
  {
      Shape result;
      int height = 0;
      int width = 0;
      Scanner data = new Scanner(layout);
      char[][] temp;
      while(data.hasNextLine())
      {
          String line = data.nextLine();
          height = line.length();
          width++;
      }
      temp = new char[height][width];

      Scanner data2 = new Scanner(layout);
      while(data2.hasNextLine())
      {
          String line2 = data2.nextLine();
          if(line2.charAt(0) == '.' && line2.charAt(width) == '.')
              throw new FitItException("Empty borders!");

        else {

            for (int r = 0; r < height; r++)
                for (int c = 0; c < width; c++) {
                    // System.out.println(line2.charAt(c));

                    if (temp[r][c] == '.') {
                        temp[r][c] = displayChar;
                    }
                    System.out.println(line2.charAt(temp[r][c]));

                    }
            }
      }
      result = new CreateShape(height, width, displayChar, layout);
      return result;
  }

Answer 1

还有一些事情我还不清楚，所以我集中精力将布局解析为二维字符数组并检查您指定的约束。希望这能让您根据自己的具体需求进行调整:

public static char[][] parseShape(String layout, char displayChar) throws Exception {
    int height = 0;
    Scanner data = new Scanner(layout);
    ArrayList<String> lines = new ArrayList<String>();

    // parse layout into an array of lines to determine dimensions
    while (data.hasNextLine()) {
        String line = data.nextLine();
        lines.add(line);
        height = line.length();
    }
    int width = lines.size();
    char[][] temp = new char[height][width];
    Boolean row0 = false;
    Boolean col0 = false;
    Boolean rowLast = false;
    Boolean colLast = false;

    // parse array of lines in char array and check for constraints
    for (int w = 0; w < width; w++) {
        String line = lines.get(w);
        for (int h = 0; h < height; h++) {
            char c = line.charAt(h);
            if (c == displayChar) {

                // we are looking at the display characters,
                // check if we're in any of rows of columns that matter
                if (h == 0)
                    row0 = true;
                if (w == 0)
                    col0 = true;
                if (h == height - 1)
                    rowLast = true;
                if (w == width - 1)
                    colLast = true;
            }
            temp[h][w] = c;
        }
    }

    // if any of the constraints are not true, the layout is invalid
    if(!row0) {
        throw new Exception("no block in Oth row");
    }
    if(!col0) {
        throw new Exception("no block in Oth column");
    }
    if(!rowLast) {
        throw new Exception("no block in last row");
    }
    if(!colLast) {
        throw new Exception("no block in last column");
    }
    return temp;
}

基本上，我们必须解析整个布局并累积满足的约束，而不是检查不满足的约束。只有到最后我们才会知道他们是否都不满意。