如何更快地阅读BufferedReader

Question

我想优化这段代码:

InputStream is = rp.getEntity().getContent();      

BufferedReader reader = new BufferedReader(new InputStreamReader(is));

String text = "";
String aux = "";

while ((aux = reader.readLine()) != null) {
        text += aux;
      }

问题是我不知道如何读取bufferedreader的内容并以比我上面更快的方式将其复制到String中.我需要花费尽可能少的时间.谢谢

Answer 1

在循环中使用字符串连接是在经典的性能杀手(因为字符串是不可变的,整个越来越大的字符串被复制为每个连接).改为:

StringBuilder builder = new StringBuilder();
String aux = "";

while ((aux = reader.readLine()) != null) {
    builder.append(aux);
}

String text = builder.toString();

Answer 2

您可以尝试Apache IOUtils.toString.这就是他们所做的:

StringWriter sw = new StringWriter();
char[] buffer = new char[1024 * 4];
int n = 0;
while (-1 != (n = input.read(buffer))) {
    sw.write(buffer, 0, n);
}
String text = sw.toString();

Answer 3

当BufferedReader从套接字中,有必要补充bufferedReader.ready():

BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

StringBuilder sb= new StringBuilder();
String line = "";

while (br.ready() && (line = br.readLine()) != null) {
    sb.append(line + "\r\n");
}

String result = sb.toString();