package com.winterbe.java8.samples.misc;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* @author Benjamin Winterberg
*/
public class Files1 {
public static void main(String[] args) throws IOException {
testWalk();
testFind();
testList();
testLines();
testReader();
testWriter();
testReadWriteLines();
testReaderLines();
}
private static void testReaderLines() throws IOException {
Path path = Paths.get("res/nashorn1.js");
try (BufferedReader reader = Files.newBufferedReader(path)) {
long countPrints = reader
.lines()
.filter(line -> line.contains("print"))
.count();
System.out.println(countPrints);
}
}
private static void testWriter() throws IOException {
Path path = Paths.get("res/output.js");
try (BufferedWriter writer = Files.newBufferedWriter(path)) {
writer.write("print('Hello World');");
}
}
private static void testReader() throws IOException {
Path path = Paths.get("res/nashorn1.js");
try (BufferedReader reader = Files.newBufferedReader(path)) {
System.out.println(reader.readLine());
}
}
private static void testWalk() throws IOException {
Path start = Paths.get("");
int maxDepth = 5;
try (Stream<Path> stream = Files.walk(start, maxDepth)) {
String joined = stream
.map(String::valueOf)
.filter(path -> path.endsWith(".js"))
.collect(Collectors.joining("; "));
System.out.println("walk(): " + joined);
}
}
private static void testFind() throws IOException {
Path start = Paths.get("");
int maxDepth = 5;
try (Stream<Path> stream = Files.find(start, maxDepth, (path, attr) ->
String.valueOf(path).endsWith(".js"))) {
String joined = stream
.sorted()
.map(String::valueOf)
.collect(Collectors.joining("; "));
System.out.println("find(): " + joined);
}
}
private static void testList() throws IOException {
try (Stream<Path> stream = Files.list(Paths.get(""))) {
String joined = stream
.map(String::valueOf)
.filter(path -> !path.startsWith("."))
.sorted()
.collect(Collectors.joining("; "));
System.out.println("list(): " + joined);
}
}
private static void testLines() throws IOException {
try (Stream<String> stream = Files.lines(Paths.get("res/nashorn1.js"))) {
stream
.filter(line -> line.contains("print"))
.map(String::trim)
.forEach(System.out::println);
}
}
private static void testReadWriteLines() throws IOException {
List<String> lines = Files.readAllLines(Paths.get("res/nashorn1.js"));
lines.add("print('foobar');");
Files.write(Paths.get("res", "nashorn1-modified.js"), lines);
}
}