Here you can find the source of copyLarge(Reader input, Writer output)
private static long copyLarge(Reader input, Writer output) throws IOException
//package com.java2s; /*//from w w w .j a v a2 s . c om * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.io.IOException; import java.io.Reader; import java.io.Writer; public class Main { private static long copyLarge(Reader input, Writer output) throws IOException { char[] buffer = new char[1024 * 4]; long count = 0; int n = 0; while (-1 != (n = input.read(buffer))) { output.write(buffer, 0, n); count += n; } return count; } }