遇到 NegativeArraySizeException 怎么解决？java报错

遇到 NegativeArraySizeException 怎么解决？java报错

在编写java的样例代码时出现这种问题。这种情况应该如何解决和避免那？

try{
     connection = (HttpConnection)Connector.open("http://someurl.xml",Connector.READ_WRITE);
     URLEncodedPostData postData = new URLEncodedPostData(URLEncodedPostData.DEFAULT_CHARSET, false);
     postData.append("username", "loginapi");
     postData.append("password", "myapilogin");
     postData.append("term", word);
 
     connection.setRequestMethod(HttpConnection.POST);
     connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
     connection.setRequestProperty("User-Agent","Profile/MIDP-2.0 Configuration/CLDC-1.0");
     requestOut = connection.openOutputStream();
     requestOut.write(postData.getBytes());
     String contentType = connection.getHeaderField("Content-type");
     detailIn = connection.openInputStream();        
     int length = (int) connection.getLength();
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     if(length > 0){//这里长度没有判定的情况下，byte array长度若为-1会产生错误
         byte info[] = new byte[length];
         int bytesRead = detailIn.read(info);
         while(bytesRead > 0) {
             baos.write(info, 0, bytesRead);
             bytesRead = detailIn.read(info);
             }
         baos.close();
         connection.close();
         requestSuceeded(baos.toByteArray(), contentType);
 
         detailIn.read(info);
     }
     else
     {
          System.out.println("Negative array size");
     }
           requestOut.close();
           detailIn.close();
           connection.close();
    }

原因是什么，为什么会发生异常，以及下面到底发生了什么。如果有人能帮忙？提前谢谢