首页 \ 问答 \ 类型不匹配：boolean []，Boolean []，ArrayList (Type mismatch: boolean[], Boolean[], ArrayList)

类型不匹配：boolean []，Boolean []，ArrayList (Type mismatch: boolean[], Boolean[], ArrayList)

 我试图从文本文件构造一个boolean [] []。 我正在读取每个字符，存储在ArrayList中（1s为true，0为false）。 我试过ArrayList，但得到了编译错误，意外的元素。 所以，我构建一个ArrayList，并尝试将其存储在ArrayList>中。 我的最后一个问题是在以下方法中布尔值和布尔值之间的类型差异。 seedInProgress是由finishLine（）构造的ArrayList>。 我试图将它全部复制到for循环中的boolean [] []。  
public void finishSeed(ArrayList<Boolean> lastLine) {
    finishLine(lastLine);
    seed = new boolean[seedInProgress.size()][seedInProgress.get(0).size()];
    for (int i = 0; i < seedInProgress.size(); i++ ) {
        seed[i] = seedInProgress.get(i).toArray()
    }
}
 
 错误是：  
SeedFactory.java:75: error: incompatible types
            seed[i] = seedInProgress.get(i).toArray();
                                                   ^
  required: boolean[]
  found:    Object[]
1 error
 
 但我无法将其强制转换为boolean []，而Boolean []仍然是Object []。  
 如何从ArrayList获取boolean []，或者如何创建ArrayList？ 

I am trying to construct a boolean[][] from a text file. I am reading in each character, storing in an ArrayList (1s as true and 0s as false). I tried ArrayList, but got compile errors, unexpected element. So, I build an ArrayList, and try to store it in an ArrayList>. My last problem is with the type difference between boolean and Boolean in the following method. seedInProgress is the ArrayList> constructed by finishLine(). I am trying to copy it all out to a boolean[][] inside the for loop. 
public void finishSeed(ArrayList<Boolean> lastLine) {
    finishLine(lastLine);
    seed = new boolean[seedInProgress.size()][seedInProgress.get(0).size()];
    for (int i = 0; i < seedInProgress.size(); i++ ) {
        seed[i] = seedInProgress.get(i).toArray()
    }
}
 
The error is:  
SeedFactory.java:75: error: incompatible types
            seed[i] = seedInProgress.get(i).toArray();
                                                   ^
  required: boolean[]
  found:    Object[]
1 error
 
but I can't cast it to boolean[], and Boolean[] is still an Object[]. 
How can I get a boolean[] from an ArrayList, or alternatively, how can I make an ArrayList?

原文：https://stackoverflow.com/questions/18794254

更新时间：2023-12-05 22:12

最满意答案

 逐行浏览文件并使用堆栈。 一些事情：  
<?php

// You'd have to implement the database yourself!
$db = new Database();
$db->startTransaction();

$stack = array();
$fh    = fopen("my-file", "r");
$i     = 0;
while (($buffer = fgets($handle, 4096)) !== false) {
  if (!isset($buffer[0])) {
    continue;
  }

  switch ($buffer[0]) {
    case "A":
      // Do something ...
      break;

    case "C":
      // Do something ...
      break;

    case "C":
      if ($stack[$i] != "C") {
        trigger_error("Line D without preceding line C");
      }
      // Do something ...
      break;

     // More stuff ...
  }

  $stack[$i++] = $buffer;
  $db->insert("INSERT INTO table (line) VALUES ($buffer)");
}

$db->commitTransaction();

?>
 
 当然，有比丑陋的switch更好的解决方案，但它很快就会出现问题。 您的数据库设计答案无法回答，因为我们对这些要求一无所知。 总而言之，考虑发布你的工作并询问有关一小部分大问题的具体问题，而不是要求解决大问题。 

Go through the file line by line and use a stack. Something along the lines: 
<?php

// You'd have to implement the database yourself!
$db = new Database();
$db->startTransaction();

$stack = array();
$fh    = fopen("my-file", "r");
$i     = 0;
while (($buffer = fgets($handle, 4096)) !== false) {
  if (!isset($buffer[0])) {
    continue;
  }

  switch ($buffer[0]) {
    case "A":
      // Do something ...
      break;

    case "C":
      // Do something ...
      break;

    case "C":
      if ($stack[$i] != "C") {
        trigger_error("Line D without preceding line C");
      }
      // Do something ...
      break;

     // More stuff ...
  }

  $stack[$i++] = $buffer;
  $db->insert("INSERT INTO table (line) VALUES ($buffer)");
}

$db->commitTransaction();

?>
 
Of course there are better solutions than the ugly switch, but it's quick'n'dirty. Your database design answer is impossible to answer because we have no clue about the requirements. All in all consider posting your work and ask specific questions regarding a small piece of a big problem and not asking to solve big problems.

类型不匹配：boolean []，Boolean []，ArrayList (Type mismatch: boolean[], Boolean[], ArrayList)

最满意答案

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