diff --git a/core-java-modules/core-java-io/README.md b/core-java-modules/core-java-io/README.md index 2c6c3363cb..b8bec7aa5e 100644 --- a/core-java-modules/core-java-io/README.md +++ b/core-java-modules/core-java-io/README.md @@ -3,7 +3,7 @@ This module contains articles about core Java input and output (IO) ### Relevant Articles: -- [How to Read a File in Java](https://www.baeldung.com/reading-file-in-java) +- [Java – Read from File](https://www.baeldung.com/java-read-file) - [Read a File into an ArrayList](https://www.baeldung.com/java-file-to-arraylist) - [Java – Directory Size](https://www.baeldung.com/java-folder-size) - [File Size in Java](https://www.baeldung.com/java-file-size) diff --git a/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/FileOperationsManualTest.java b/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/FileOperationsManualTest.java deleted file mode 100644 index b837c6b4dd..0000000000 --- a/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/FileOperationsManualTest.java +++ /dev/null @@ -1,134 +0,0 @@ -package com.baeldung.readfile; - -import org.apache.commons.io.FileUtils; -import org.apache.commons.io.IOUtils; -import org.hamcrest.CoreMatchers; -import org.hamcrest.Matchers; -import org.junit.Test; - -import java.io.BufferedReader; -import java.io.File; -import java.io.FileInputStream; -import java.io.IOException; -import java.io.InputStream; -import java.io.InputStreamReader; -import java.net.URISyntaxException; -import java.net.URL; -import java.net.URLConnection; -import java.nio.file.Files; -import java.nio.file.Path; -import java.nio.file.Paths; -import java.util.stream.Collectors; -import java.util.stream.Stream; - -import static org.junit.Assert.assertEquals; -import static org.junit.Assert.assertThat; - -public class FileOperationsManualTest { - - @Test - public void givenFileName_whenUsingClassloader_thenFileData() throws IOException { - String expectedData = "Hello World from fileTest.txt!!!"; - - ClassLoader classLoader = getClass().getClassLoader(); - File file = new File(classLoader.getResource("fileTest.txt").getFile()); - InputStream inputStream = new FileInputStream(file); - String data = readFromInputStream(inputStream); - - assertEquals(expectedData, data.trim()); - } - - @Test - public void givenFileNameAsAbsolutePath_whenUsingClasspath_thenFileData() throws IOException { - String expectedData = "Hello World from fileTest.txt!!!"; - - Class clazz = FileOperationsManualTest.class; - InputStream inputStream = clazz.getResourceAsStream("/fileTest.txt"); - String data = readFromInputStream(inputStream); - - assertEquals(expectedData, data.trim()); - } - - @Test - public void givenFileName_whenUsingJarFile_thenFileData() throws IOException { - String expectedData = "MIT License"; - - Class clazz = Matchers.class; - InputStream inputStream = clazz.getResourceAsStream("/LICENSE.txt"); - String data = readFromInputStream(inputStream); - - assertThat(data.trim(), CoreMatchers.containsString(expectedData)); - } - - @Test - public void givenURLName_whenUsingURL_thenFileData() throws IOException { - String expectedData = "Example Domain"; - - URL urlObject = new URL("http://www.example.com/"); - - URLConnection urlConnection = urlObject.openConnection(); - - InputStream inputStream = urlConnection.getInputStream(); - String data = readFromInputStream(inputStream); - - assertThat(data.trim(), CoreMatchers.containsString(expectedData)); - } - - @Test - public void givenFileName_whenUsingFileUtils_thenFileData() throws IOException { - String expectedData = "Hello World from fileTest.txt!!!"; - - ClassLoader classLoader = getClass().getClassLoader(); - File file = new File(classLoader.getResource("fileTest.txt").getFile()); - String data = FileUtils.readFileToString(file, "UTF-8"); - - assertEquals(expectedData, data.trim()); - } - - @Test - public void givenFilePath_whenUsingFilesReadAllBytes_thenFileData() throws IOException, URISyntaxException { - String expectedData = "Hello World from fileTest.txt!!!"; - - Path path = Paths.get(getClass().getClassLoader().getResource("fileTest.txt").toURI()); - - byte[] fileBytes = Files.readAllBytes(path); - String data = new String(fileBytes); - - assertEquals(expectedData, data.trim()); - } - - @Test - public void givenFilePath_whenUsingFilesLines_thenFileData() throws IOException, URISyntaxException { - String expectedData = "Hello World from fileTest.txt!!!"; - - Path path = Paths.get(getClass().getClassLoader().getResource("fileTest.txt").toURI()); - - Stream lines = Files.lines(path); - String data = lines.collect(Collectors.joining("\n")); - lines.close(); - - assertEquals(expectedData, data.trim()); - } - - private String readFromInputStream(InputStream inputStream) throws IOException { - StringBuilder resultStringBuilder = new StringBuilder(); - try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream))) { - String line; - while ((line = bufferedReader.readLine()) != null) { - resultStringBuilder.append(line).append("\n"); - } - } - - return resultStringBuilder.toString(); - } - - @Test - public void givenFileName_whenUsingIOUtils_thenFileData() throws IOException { - String expectedData = "This is a content of the file"; - - FileInputStream fis = new FileInputStream("src/test/resources/fileToRead.txt"); - String data = IOUtils.toString(fis, "UTF-8"); - - assertEquals(expectedData, data.trim()); - } -} \ No newline at end of file diff --git a/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/JavaReadFromFileUnitTest.java b/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/JavaReadFromFileUnitTest.java index a4ccaad594..aa37a22e1f 100644 --- a/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/JavaReadFromFileUnitTest.java +++ b/core-java-modules/core-java-io/src/test/java/com/baeldung/readfile/JavaReadFromFileUnitTest.java @@ -1,11 +1,15 @@ package com.baeldung.readfile; +import org.apache.commons.io.FileUtils; +import org.apache.commons.io.IOUtils; +import org.hamcrest.CoreMatchers; +import org.hamcrest.Matchers; import org.junit.Test; -import org.junit.Ignore; -import org.slf4j.Logger; -import org.slf4j.LoggerFactory; import java.io.*; +import java.net.URISyntaxException; +import java.net.URL; +import java.net.URLConnection; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; import java.nio.charset.Charset; @@ -13,55 +17,148 @@ import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.Scanner; +import java.util.stream.Collectors; +import java.util.stream.Stream; +import static org.hamcrest.MatcherAssert.assertThat; import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertTrue; public class JavaReadFromFileUnitTest { - private static final Logger LOG = LoggerFactory.getLogger(JavaReadFromFileUnitTest.class); - @Test public void whenReadWithBufferedReader_thenCorrect() throws IOException { - final String expected_value = "Hello world"; + final String expected_value = "Hello, world!"; - final BufferedReader reader = new BufferedReader(new FileReader("src/test/resources/test_read.in")); + final BufferedReader reader = new BufferedReader(new FileReader("src/test/resources/fileTest.txt")); final String currentLine = reader.readLine(); reader.close(); assertEquals(expected_value, currentLine); } + @Test + public void givenFileName_whenUsingClassloader_thenFileData() throws IOException { + String expectedData = "Hello, world!"; + + ClassLoader classLoader = getClass().getClassLoader(); + File file = new File(classLoader.getResource("fileTest.txt").getFile()); + InputStream inputStream = new FileInputStream(file); + String data = readFromInputStream(inputStream); + + assertEquals(expectedData, data.trim()); + } + + @Test + public void givenFileNameAsAbsolutePath_whenUsingClasspath_thenFileData() throws IOException { + String expectedData = "Hello, world!"; + + Class clazz = JavaReadFromFileUnitTest.class; + InputStream inputStream = clazz.getResourceAsStream("/fileTest.txt"); + String data = readFromInputStream(inputStream); + + assertEquals(expectedData, data.trim()); + } + + @Test + public void givenFileName_whenUsingJarFile_thenFileData() throws IOException { + String expectedData = "BSD License"; + + Class clazz = Matchers.class; + InputStream inputStream = clazz.getResourceAsStream("/LICENSE.txt"); + String data = readFromInputStream(inputStream); + + assertThat(data.trim(), CoreMatchers.containsString(expectedData)); + } + + @Test + public void givenURLName_whenUsingURL_thenFileData() throws IOException { + String expectedData = "Example Domain"; + + URL urlObject = new URL("http://www.example.com/"); + + URLConnection urlConnection = urlObject.openConnection(); + + InputStream inputStream = urlConnection.getInputStream(); + String data = readFromInputStream(inputStream); + + assertThat(data.trim(), CoreMatchers.containsString(expectedData)); + } + + @Test + public void givenFileName_whenUsingFileUtils_thenFileData() throws IOException { + String expectedData = "Hello, world!"; + + ClassLoader classLoader = getClass().getClassLoader(); + File file = new File(classLoader.getResource("fileTest.txt").getFile()); + String data = FileUtils.readFileToString(file, "UTF-8"); + + assertEquals(expectedData, data.trim()); + } + + @Test + public void givenFilePath_whenUsingFilesReadAllBytes_thenFileData() throws IOException, URISyntaxException { + String expectedData = "Hello, world!"; + + Path path = Paths.get(getClass().getClassLoader().getResource("fileTest.txt").toURI()); + + byte[] fileBytes = Files.readAllBytes(path); + String data = new String(fileBytes); + + assertEquals(expectedData, data.trim()); + } + + @Test + public void givenFilePath_whenUsingFilesLines_thenFileData() throws IOException, URISyntaxException { + String expectedData = "Hello, world!"; + + Path path = Paths.get(getClass().getClassLoader().getResource("fileTest.txt").toURI()); + + Stream lines = Files.lines(path); + String data = lines.collect(Collectors.joining("\n")); + lines.close(); + + assertEquals(expectedData, data.trim()); + } + + @Test + public void givenFileName_whenUsingIOUtils_thenFileData() throws IOException { + String expectedData = "Hello, world!"; + + FileInputStream fis = new FileInputStream("src/test/resources/fileTest.txt"); + String data = IOUtils.toString(fis, "UTF-8"); + + assertEquals(expectedData, data.trim()); + } + @Test public void whenReadWithScanner_thenCorrect() throws IOException { - final Scanner scanner = new Scanner(new File("src/test/resources/test_read1.in")); + final Scanner scanner = new Scanner(new File("src/test/resources/fileTest.txt")); scanner.useDelimiter(" "); assertTrue(scanner.hasNext()); - assertEquals("Hello", scanner.next()); - assertEquals("world", scanner.next()); - assertEquals(1, scanner.nextInt()); + assertEquals("Hello,", scanner.next()); + assertEquals("world!", scanner.next()); scanner.close(); - } @Test public void whenReadWithScannerTwoDelimiters_thenCorrect() throws IOException { - final Scanner scanner = new Scanner(new File("src/test/resources/test_read2.in")); - scanner.useDelimiter(",| "); + final Scanner scanner = new Scanner(new File("src/test/resources/fileTest.txt")); + scanner.useDelimiter("\\s|,"); - assertTrue(scanner.hasNextInt()); - assertEquals(2, scanner.nextInt()); - assertEquals(3, scanner.nextInt()); - assertEquals(4, scanner.nextInt()); + assertTrue(scanner.hasNext()); + assertEquals("Hello", scanner.next()); + assertEquals("", scanner.next()); + assertEquals("world!", scanner.next()); scanner.close(); } @Test public void whenReadWithStreamTokenizer_thenCorrectTokens() throws IOException { - final FileReader reader = new FileReader("src/test/resources/test_read3.in"); + final FileReader reader = new FileReader("src/test/resources/fileTestTokenizer.txt"); final StreamTokenizer tokenizer = new StreamTokenizer(reader); tokenizer.nextToken(); @@ -78,49 +175,36 @@ public class JavaReadFromFileUnitTest { @Test public void whenReadWithDataInputStream_thenCorrect() throws IOException { - final String expected_value = "Hello"; + String expectedValue = "Hello, world!"; + String file ="src/test/resources/fileTest.txt"; - String result; - final DataInputStream reader = new DataInputStream(new FileInputStream("src/test/resources/test_read4.in")); - result = reader.readUTF(); - reader.close(); + String result = null; - assertEquals(expected_value, result); - } + DataInputStream reader = new DataInputStream(new FileInputStream(file)); + int nBytesToRead = reader.available(); + if(nBytesToRead > 0) { + byte[] bytes = new byte[nBytesToRead]; + reader.read(bytes); + result = new String(bytes); + } - public void whenReadTwoFilesWithSequenceInputStream_thenCorrect() throws IOException { - final int expected_value1 = 2000; - final int expected_value2 = 5000; - - final FileInputStream stream1 = new FileInputStream("src/test/resources/test_read5.in"); - final FileInputStream stream2 = new FileInputStream("src/test/resources/test_read6.in"); - - final SequenceInputStream sequence = new SequenceInputStream(stream1, stream2); - final DataInputStream reader = new DataInputStream(sequence); - - assertEquals(expected_value1, reader.readInt()); - assertEquals(expected_value2, reader.readInt()); - - reader.close(); - stream2.close(); + assertEquals(expectedValue, result); } @Test - @Ignore // TODO public void whenReadUTFEncodedFile_thenCorrect() throws IOException { final String expected_value = "青空"; - final BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("src/test/resources/test_read7.in"), "UTF-8")); + final BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("src/test/resources/fileTestUtf8.txt"), "UTF-8")); final String currentLine = reader.readLine(); reader.close(); - LOG.debug(currentLine); - + assertEquals(expected_value, currentLine); } @Test public void whenReadFileContentsIntoString_thenCorrect() throws IOException { - final String expected_value = "Hello world \n Test line \n"; - final BufferedReader reader = new BufferedReader(new FileReader("src/test/resources/test_read8.in")); + final String expected_value = "Hello, world!\n"; + final BufferedReader reader = new BufferedReader(new FileReader("src/test/resources/fileTest.txt")); final StringBuilder builder = new StringBuilder(); String currentLine = reader.readLine(); while (currentLine != null) { @@ -136,8 +220,8 @@ public class JavaReadFromFileUnitTest { @Test public void whenReadWithFileChannel_thenCorrect() throws IOException { - final String expected_value = "Hello world"; - final RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); + final String expected_value = "Hello, world!"; + final RandomAccessFile reader = new RandomAccessFile("src/test/resources/fileTest.txt", "r"); final FileChannel channel = reader.getChannel(); int bufferSize = 1024; @@ -154,8 +238,8 @@ public class JavaReadFromFileUnitTest { @Test public void whenReadSmallFileJava7_thenCorrect() throws IOException { - final String expected_value = "Hello world"; - final Path path = Paths.get("src/test/resources/test_read.in"); + final String expected_value = "Hello, world!"; + final Path path = Paths.get("src/test/resources/fileTest.txt"); final String read = Files.readAllLines(path, Charset.defaultCharset()).get(0); assertEquals(expected_value, read); @@ -163,12 +247,24 @@ public class JavaReadFromFileUnitTest { @Test public void whenReadLargeFileJava7_thenCorrect() throws IOException { - final String expected_value = "Hello world"; + final String expected_value = "Hello, world!"; - final Path path = Paths.get("src/test/resources/test_read.in"); + final Path path = Paths.get("src/test/resources/fileTest.txt"); final BufferedReader reader = Files.newBufferedReader(path, Charset.defaultCharset()); final String line = reader.readLine(); assertEquals(expected_value, line); } + private String readFromInputStream(InputStream inputStream) throws IOException { + StringBuilder resultStringBuilder = new StringBuilder(); + try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream))) { + String line; + while ((line = bufferedReader.readLine()) != null) { + resultStringBuilder.append(line).append("\n"); + } + } + + return resultStringBuilder.toString(); + } + } diff --git a/core-java-modules/core-java-io/src/test/resources/fileTest.txt b/core-java-modules/core-java-io/src/test/resources/fileTest.txt index ce4bea208b..5dd01c177f 100644 --- a/core-java-modules/core-java-io/src/test/resources/fileTest.txt +++ b/core-java-modules/core-java-io/src/test/resources/fileTest.txt @@ -1 +1 @@ -Hello World from fileTest.txt!!! \ No newline at end of file +Hello, world! \ No newline at end of file diff --git a/core-java-modules/core-java-io/src/test/resources/test_read3.in b/core-java-modules/core-java-io/src/test/resources/fileTestTokenizer.txt similarity index 100% rename from core-java-modules/core-java-io/src/test/resources/test_read3.in rename to core-java-modules/core-java-io/src/test/resources/fileTestTokenizer.txt diff --git a/core-java-modules/core-java-io/src/test/resources/test_read7.in b/core-java-modules/core-java-io/src/test/resources/fileTestUtf8.txt similarity index 100% rename from core-java-modules/core-java-io/src/test/resources/test_read7.in rename to core-java-modules/core-java-io/src/test/resources/fileTestUtf8.txt diff --git a/core-java-modules/core-java-io/src/test/resources/test_read1.in b/core-java-modules/core-java-io/src/test/resources/test_read1.in deleted file mode 100644 index 1e46242993..0000000000 --- a/core-java-modules/core-java-io/src/test/resources/test_read1.in +++ /dev/null @@ -1 +0,0 @@ -Hello world 1 \ No newline at end of file diff --git a/core-java-modules/core-java-io/src/test/resources/test_read2.in b/core-java-modules/core-java-io/src/test/resources/test_read2.in deleted file mode 100644 index fe47dc003b..0000000000 --- a/core-java-modules/core-java-io/src/test/resources/test_read2.in +++ /dev/null @@ -1 +0,0 @@ -2,3 4 \ No newline at end of file diff --git a/core-java-modules/core-java-io/src/test/resources/test_read4.in b/core-java-modules/core-java-io/src/test/resources/test_read4.in deleted file mode 100644 index 5727d54bfc..0000000000 Binary files a/core-java-modules/core-java-io/src/test/resources/test_read4.in and /dev/null differ diff --git a/core-java-modules/core-java-io/src/test/resources/test_read8.in b/core-java-modules/core-java-io/src/test/resources/test_read8.in deleted file mode 100644 index 10fc1aac8a..0000000000 --- a/core-java-modules/core-java-io/src/test/resources/test_read8.in +++ /dev/null @@ -1,2 +0,0 @@ -Hello world - Test line