public void testFind() throws IOException {
PathBiPredicate pred = new PathBiPredicate((path, attrs) -> true);
try (Stream<Path> s = Files.find(testFolder, Integer.MAX_VALUE, pred)) {
Set<Path> result = s.collect(Collectors.toCollection(TreeSet::new));
assertEquals(pred.visited(), all);
assertEquals(result.toArray(new Path[0]), pred.visited());
}
pred = new PathBiPredicate((path, attrs) -> attrs.isSymbolicLink());
try (Stream<Path> s = Files.find(testFolder, Integer.MAX_VALUE, pred)) {
s.forEach(path -> assertTrue(Files.isSymbolicLink(path)));
assertEquals(pred.visited(), all);
}
pred = new PathBiPredicate((path, attrs) -> path.getFileName().toString().startsWith("e"));
try (Stream<Path> s = Files.find(testFolder, Integer.MAX_VALUE, pred)) {
s.forEach(path -> assertEquals(path.getFileName().toString(), "empty"));
assertEquals(pred.visited(), all);
}
pred =
new PathBiPredicate(
(path, attrs) ->
path.getFileName().toString().startsWith("l") && attrs.isRegularFile());
try (Stream<Path> s = Files.find(testFolder, Integer.MAX_VALUE, pred)) {
s.forEach(path -> fail("Expect empty stream"));
assertEquals(pred.visited(), all);
}
}
@Test
public void fileExistTest() throws IOException {
long countDir =
Files.find(Paths.get(rootPath), 35, (path, attributes) -> attributes.isDirectory()).count();
assertEquals(30, countDir);
long countFiles =
Files.find(Paths.get(rootPath), 35, (path, attributes) -> attributes.isRegularFile())
.count();
assertEquals(499950, countFiles);
}
public void testClosedStream() throws IOException {
try (Stream<Path> s = Files.list(testFolder)) {
s.close();
Object[] actual = s.sorted().toArray();
fail("Operate on closed stream should throw IllegalStateException");
} catch (IllegalStateException ex) {
// expected
}
try (Stream<Path> s = Files.walk(testFolder)) {
s.close();
Object[] actual = s.sorted().toArray();
fail("Operate on closed stream should throw IllegalStateException");
} catch (IllegalStateException ex) {
// expected
}
try (Stream<Path> s = Files.find(testFolder, Integer.MAX_VALUE, (p, attr) -> true)) {
s.close();
Object[] actual = s.sorted().toArray();
fail("Operate on closed stream should throw IllegalStateException");
} catch (IllegalStateException ex) {
// expected
}
}
public static void main(String[] args) 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);
}
Path start = Paths.get("");
int maxDepth = 5;
try (Stream<Path> stream =
Files.find(start, maxDepth, (path, attr) -> String.valueOf(path).endsWith(".java"))) {
String joined = stream.sorted().map(String::valueOf).collect(Collectors.joining("; "));
System.out.println("Found: " + joined);
}
try (Stream<Path> stream = Files.walk(start, maxDepth)) {
String joined =
stream
.map(String::valueOf)
.filter(path -> path.endsWith(".java"))
.sorted()
.collect(Collectors.joining("; "));
System.out.println("walk(): " + joined);
}
List<String> lines = Files.readAllLines(Paths.get("src/golf.sh"));
lines.add("puts 'foobar'");
Path path = Paths.get("src/golf-modified.sh");
Files.write(path, lines);
try (Stream<String> stream = Files.lines(path)) {
stream.filter(line -> line.contains("puts")).map(String::trim).forEach(System.out::println);
}
System.out.println("a" == "a");
System.out.println("a" != new String("a"));
System.out.println(null != "a");
System.out.println("a".equals("a"));
try (BufferedReader reader = Files.newBufferedReader(path)) {
while (reader.ready()) System.out.println(reader.readLine());
}
try (BufferedWriter writer = Files.newBufferedWriter(Paths.get("hello-world.sh"))) {
writer.write("puts 'Hello world'");
}
try (BufferedReader reader = Files.newBufferedReader(path)) {
long countPuts = reader.lines().filter(line -> line.contains("put")).count();
System.out.println(countPuts);
}
}
public static void main(String[] args) {
// Methods in Comparator
List<Person> people = new ArrayList<>();
people.sort(
Comparator.comparing(Person::getLastName)
.thenComparing(Person::getFirstName)
.thenComparing(
Person::getEmailAddress, Comparator.nullsLast(String.CASE_INSENSITIVE_ORDER)));
// Old way of initializing ThreadLocal:
ThreadLocal<List<String>> oldThreadLocalString =
new ThreadLocal<List<String>>() {
@Override
public List<String> initialValue() {
return new ArrayList<>();
}
};
System.out.println(oldThreadLocalString.get());
// New way:
ThreadLocal<List<String>> newThreadLocalString = ThreadLocal.withInitial(ArrayList::new);
System.out.println(newThreadLocalString.get());
// Java Optional
Optional<Integer> optional = new ArrayList<Integer>().stream().min(Integer::compareTo);
System.out.println(optional);
// Files can now return streams
try {
Stream stream = Files.list(Paths.get("c:\\temp\\"));
stream = Files.lines(Paths.get("c:\\temp\\"), Charset.forName("UTF_32"));
stream = Files.find(Paths.get("c:\\"), 5, (T, U) -> (T == U));
} catch (IOException e) {
UncheckedIOException ex = new UncheckedIOException("cause", e);
System.out.println(ex.getMessage());
}
// Rejoice, for we finally have string joins!
String joinExample = String.join(",", "a", "b", "c", "4", "E", "6");
System.out.println(joinExample);
StringJoiner joiner = new StringJoiner("-");
joiner.add("abbie");
joiner.add("doobie");
System.out.println(joiner.toString());
}
static void filesTest() {
// Files.list
try {
try (Stream<Path> stream = Files.list(Paths.get("/opt"))) {
String joined =
stream
.map(String::valueOf)
.filter(path -> !path.startsWith("."))
.sorted()
.collect(Collectors.joining("; "));
System.out.println("List path /opt : " + joined);
}
} catch (IOException e) {
e.printStackTrace();
}
// Files.find
Path start = Paths.get("/Users/alibaba/Downloads/2016113");
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("Files find : " + joined);
} catch (IOException e) {
e.printStackTrace();
}
// Files.walk
try (Stream<Path> stream = Files.walk(start, maxDepth)) {
String joined =
stream
.map(String::valueOf)
.filter(path -> path.endsWith(".js"))
.sorted()
.collect(Collectors.joining("; "));
System.out.println("Files walk : " + joined);
} catch (IOException e) {
e.printStackTrace();
}
// Files.readAllLines
try {
String p = "/Users/alibaba/linuxsir.txt";
List<String> lines = Files.readAllLines(Paths.get(p));
lines.add("print('foobar');");
Files.write(Paths.get(p), lines);
lines.remove(lines.size() - 1);
System.out.println("readAllLines " + lines);
Files.write(Paths.get(p), lines);
} catch (IOException e) {
e.printStackTrace();
}
// Files.lines
try (Stream<String> stream = Files.lines(Paths.get("/Users/alibaba/linuxsir.txt"))) {
stream.filter(line -> line.contains("w")).map(String::valueOf).forEach(System.out::println);
} catch (IOException e) {
e.printStackTrace();
}
// Files.newBufferedReader&Files.newBufferedWriter
Path path = Paths.get("/Users/alibaba/linuxsir.txt");
try (BufferedReader reader = Files.newBufferedReader(path)) {
System.out.println(reader.readLine());
} catch (IOException e) {
e.printStackTrace();
}
path = Paths.get("/Users/alibaba/output.txt");
try (BufferedWriter writer = Files.newBufferedWriter(path)) {
writer.write("print('Hello World')");
} catch (IOException e) {
e.printStackTrace();
}
}