Readline 太慢 - 有更快的吗？

发布于 2024-12-09 10:23:16 字数 505 浏览 1 评论 0原文

我正在使用 BufferedReader 和 InputStreamReader 从流中读取内容，以创建从读取器创建的一个长字符串。它的行数超过 100,000 行，然后抛出 500 错误（服务器上的调用失败）。我不确定问题是什么，有没有比这种方法更快的方法？当线路数达到数千时它可以工作，但我正在处理大型数据集。

BufferedReader in = new BufferedReader(new InputStreamReader(newConnect.getInputStream()));
String inputLine;               
String xmlObject = "";
StringBuffer str = new StringBuffer();

while ((inputLine = in.readLine()) != null) {
    str.append(inputLine);
    str.toString();
}       
in.close();

提前致谢

原文

I am reading in from a stream using a BufferedReader and InputStreamReader to create one long string that gets created from the readers. It gets up to over 100,000 lines and then throws a 500 error (call failed on the server). I am not sure what is the problem, is there anything faster than this method? It works when the lines are in the thousands but i am working with large data sets.

BufferedReader in = new BufferedReader(new InputStreamReader(newConnect.getInputStream()));
String inputLine;               
String xmlObject = "";
StringBuffer str = new StringBuffer();

while ((inputLine = in.readLine()) != null) {
    str.append(inputLine);
    str.toString();
}       
in.close();

Thanks in advance

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

苦妄 2024-12-16 10:23:16

创建一个由读者创建的长字符串。

您是否有机会这样做来创建您的“长字符串”？

String string;
while(...) 
 string+=whateverComesFromTheSocket;

如果是，则将其更改为

StringBuilder str = new StringBuilder(); //Edit:Just changed StringBuffer to StringBuilder
while(...)
 str.append(whateverComesFromTheSocket);
String string = str.toString();

String 对象是不可变的，并且当您执行 str+="something" 时，会重新分配内存，并将 str+"something" 复制到新分配的区域。这是一项成本高昂的操作，运行 51,000 次是一件极其糟糕的事情。

StringBuffer和StringBuilder是String的可变兄弟，StringBuilder是非并发的，比StringBuffer效率更高。

to create one long string that gets created from the readers.

Are you by any chance doing this to create your "long string"?

String string;
while(...) 
 string+=whateverComesFromTheSocket;

If yes, then change it to

StringBuilder str = new StringBuilder(); //Edit:Just changed StringBuffer to StringBuilder
while(...)
 str.append(whateverComesFromTheSocket);
String string = str.toString();

String objects are immutable and when you do str+="something", memory is reallocated and str+"something" is copied to that newly allocated area. This is a costly operation and running it 51,000 times is an extremely bad thing to do.

StringBuffer and StringBuilder are String's mutable brothers and StringBuilder, being non-concurrent is more efficient than StringBuffer.

回复收藏 0 原文