I have a longer test to try. This takes an average of 160 ns to read each line as add it to a List (Which is likely to be what you intended as dropping the newlines is not very useful.
public static void main(String... args) throws IOException {
final int runs = 5 * 1000 * 1000;
final ServerSocket ss = new ServerSocket(0);
new Thread(new Runnable() {
@Override
public void run() {
try {
Socket serverConn = ss.accept();
String line = "Hello World!\n";
BufferedWriter br = new BufferedWriter(new OutputStreamWriter(serverConn.getOutputStream()));
for (int count = 0; count < runs; count++)
br.write(line);
serverConn.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
Socket conn = new Socket("localhost", ss.getLocalPort());
long start = System.nanoTime();
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
List<String> responseData = new ArrayList<String>();
while ((line = in.readLine()) != null) {
responseData.add(line);
}
long time = System.nanoTime() - start;
System.out.println("Average time to read a line was " + time / runs + " ns.");
conn.close();
ss.close();
}
prints
Average time to read a line was 158 ns.
If you want to build a StringBuilder, keeping newlines I would suggets the following approach.
Reader r = new InputStreamReader(conn.getInputStream());
String line;
StringBuilder sb = new StringBuilder();
char[] chars = new char[4*1024];
int len;
while((len = r.read(chars))>=0) {
sb.append(chars, 0, len);
}
Still prints
Average time to read a line was 159 ns.
In both cases, the speed is limited by the sender not the receiver. By optimising the sender, I got this timing down to 105 ns per line.