[BAEL-19088] - Move articles out of core-java-io part 3

2019-11-15 11:49:14 +02:00
parent 274aafe823
commit fe49f7c4f6
94 changed files with 114 additions and 1399 deletions
@@ -0,0 +1,64 @@
+package com.baeldung.listfiles;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.DirectoryStream;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class ListFiles {
+    public static final int DEPTH = 1;
+
+    public Set<String> listFilesUsingJavaIO(String dir) {
+        return Stream.of(new File(dir).listFiles())
+            .filter(file -> !file.isDirectory())
+            .map(File::getName)
+            .collect(Collectors.toSet());
+    }
+
+    public Set<String> listFilesUsingFileWalk(String dir, int depth) throws IOException {
+        try (Stream<Path> stream = Files.walk(Paths.get(dir), depth)) {
+            return stream.filter(file -> !Files.isDirectory(file))
+                .map(Path::getFileName)
+                .map(Path::toString)
+                .collect(Collectors.toSet());
+        }
+    }
+
+    public Set<String> listFilesUsingFileWalkAndVisitor(String dir) throws IOException {
+        Set<String> fileList = new HashSet<>();
+        Files.walkFileTree(Paths.get(dir), new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+                if (!Files.isDirectory(file)) {
+                    fileList.add(file.getFileName()
+                        .toString());
+                }
+                return FileVisitResult.CONTINUE;
+            }
+        });
+        return fileList;
+    }
+
+    public Set<String> listFilesUsingDirectoryStream(String dir) throws IOException {
+        Set<String> fileList = new HashSet<>();
+        try (DirectoryStream<Path> stream = Files.newDirectoryStream(Paths.get(dir))) {
+            for (Path path : stream) {
+                if (!Files.isDirectory(path)) {
+                    fileList.add(path.getFileName()
+                        .toString());
+                }
+            }
+        }
+        return fileList;
+    }
+
+}
@@ -1,96 +0,0 @@
-package com.baeldung.scanner;
-
-import lombok.extern.log4j.Log4j;
-import org.apache.log4j.LogManager;
-import org.apache.log4j.PropertyConfigurator;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.Properties;
-import java.util.Scanner;
-
-@Log4j
-public class HasNextVsHasNextLineDemo {
-    private static final String LINE = "----------------------------";
-    private static final String END_LINE = "--------OUTPUT--END---------\n";
-
-
-    private static final String INPUT = new StringBuilder()
-        .append("magic\tproject\n")
-        .append("     database: oracle\n")
-        .append("dependencies:\n")
-        .append("spring:foo:bar\n")
-        .append("\n").toString();
-
-    private static void hasNextBasic() {
-        printHeader("hasNext() Basic");
-        Scanner scanner = new Scanner(INPUT);
-        while (scanner.hasNext()) {
-            log.info(scanner.next());
-        }
-        log.info(END_LINE);
-        scanner.close();
-    }
-
-    private static void hasNextWithDelimiter() {
-        printHeader("hasNext() with delimiter");
-        Scanner scanner = new Scanner(INPUT);
-        while (scanner.hasNext()) {
-            String token = scanner.next();
-            if ("dependencies:".equals(token)) {
-                scanner.useDelimiter(":");
-            }
-            log.info(token);
-        }
-        log.info(END_LINE);
-        scanner.close();
-    }
-
-    private static void hasNextWithDelimiterFixed() {
-        printHeader("hasNext() with delimiter FIX");
-        Scanner scanner = new Scanner(INPUT);
-        while (scanner.hasNext()) {
-            String token = scanner.next();
-            if ("dependencies:".equals(token)) {
-                scanner.useDelimiter(":|\\s+");
-            }
-            log.info(token);
-        }
-        log.info(END_LINE);
-        scanner.close();
-    }
-
-    private static void addLineNumber() {
-        printHeader("add line number by hasNextLine() ");
-        Scanner scanner = new Scanner(INPUT);
-        int i = 0;
-        while (scanner.hasNextLine()) {
-            log.info(String.format("%d|%s", ++i, scanner.nextLine()));
-        }
-        log.info(END_LINE);
-        scanner.close();
-    }
-
-    private static void printHeader(String title) {
-        log.info(LINE);
-        log.info(title);
-        log.info(LINE);
-    }
-
-    public static void main(String[] args) throws IOException {
-        setLogger();
-        hasNextBasic();
-        hasNextWithDelimiter();
-        hasNextWithDelimiterFixed();
-        addLineNumber();
-    }
-
-    //overwrite the logger config
-    private static void setLogger() throws IOException {
-        InputStream is = HasNextVsHasNextLineDemo.class.getResourceAsStream("/scanner/log4j.properties");
-        Properties props = new Properties();
-        props.load(is);
-        LogManager.resetConfiguration();
-        PropertyConfigurator.configure(props);
-    }
-}
@@ -1,4 +0,0 @@
-log4j.rootLogger=INFO, A1
-log4j.appender.A1=org.apache.log4j.ConsoleAppender
-log4j.appender.A1.layout=org.apache.log4j.PatternLayout
-log4j.appender.A1.layout.ConversionPattern=[DEMO]%m%n