NegativeArraySizeException -1

Question

我正在開發一個通過HTTP調用RESTful服務器的Android應用程序。問題是，我收到以下錯誤：NegativeArraySizeException -1。我無法弄清爲什麼問題在發生。

我有兩個類：ReadHttpTask和HttpHelper。該錯誤似乎是由HttpHelper類中的StringBuilder引起的，或者至少是調試器顯示異常原因的地方。

ReadHttpTask：

public class ReadHttpTask extends AsyncTask<String, Void, CharSequence> { 
    @Override 
    protected CharSequence doInBackground(String...urls) { 
     String urlString = urls[0]; 
     try{ 
      CharSequence result = HttpHelper.GetHttpResponse(urlString); 
      return result; 
     } catch (IOException ex){ 
      cancel(true); 
      String errorMessage = ex.getMessage() + "\n" + urlString; 
      Log.e("Something went wrong", errorMessage); 
      return errorMessage; 
     } 
    } 
} 

HttpHelper：

public class HttpHelper { 

    public static CharSequence GetHttpResponse(String urlString) throws IOException { 
     URL url = new URL(urlString); 
     URLConnection connection = url.openConnection(); 
     if(!(connection instanceof HttpURLConnection)){ 
      throw new IOException("Not an HTTP connection"); 
     } 

     HttpURLConnection httpConnection = (HttpURLConnection) connection; 
     int responseCode = httpConnection.getResponseCode(); 
     if(responseCode != HttpURLConnection.HTTP_OK){ 
      String responseMessage = httpConnection.getResponseMessage(); 
      throw new IOException("HTTP response code: " + responseCode + " " + responseMessage); 

     } 
     InputStream inputStream = httpConnection.getInputStream(); 
     BufferedReader reader = null; 
     try{ 
      reader = new BufferedReader(new InputStreamReader(inputStream)); 
      StringBuilder result = new StringBuilder(httpConnection.getContentLength()); 
      while(true){ 
       String line = reader.readLine(); 
       if(line==null) break; 
       result.append(line); 
      } 
      return result; 
     } finally { 
      if(reader != null) reader.close(); 
     } 
    } 
} 

Answer 1

您使用從URLConnection的的getContentLength方法創建的StringBuilder的一個實例。

首先，讓我們看到的StringBuilder：

StringBuilder public StringBuilder(int capacity)

Constructs a string builder with no characters in it and an initial capacity specified by the capacity argument. Parameters:capacity - the initial capacity. Throws:NegativeArraySizeException - if the capacity argument is less than 0.

如果您打開該文檔，您將看到：

Returns

int the content length of the resource that this connection's URL references, -1 if the content length is not known, or if the content length is greater than Integer.MAX_VALUE.

所以，你有你的解決方案。如果您收到一個值，您不應創建具有特定大小的StringBuilder（如果這是-1）。如果沒有，讓SB管理是自己的大小。

像這樣創建的StringBuilder：

StringBuilder result = new StringBuilder(); //create with a size of 16 character.