Add class GuavaIOTest

guava/src/test/java/org/baeldung/guava/GuavaIOTest.java

@@ -0,0 +1,233 @@
+package org.baeldung.guava;
+
+import static org.hamcrest.Matchers.contains;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+import java.io.DataInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.IOException;
+import java.net.URL;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.google.common.base.Charsets;
+import com.google.common.base.Joiner;
+import com.google.common.collect.Lists;
+import com.google.common.io.ByteSink;
+import com.google.common.io.ByteSource;
+import com.google.common.io.ByteStreams;
+import com.google.common.io.CharSink;
+import com.google.common.io.CharSource;
+import com.google.common.io.CharStreams;
+import com.google.common.io.Files;
+import com.google.common.io.LittleEndianDataInputStream;
+import com.google.common.io.LittleEndianDataOutputStream;
+import com.google.common.io.Resources;
+
+public class GuavaIOTest {
+
+    @Test
+    public void whenWriteUsingFiles_thenWritten() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test.out");
+
+        Files.write(expected_value, file, Charsets.UTF_8);
+
+        final String result = Files.toString(file, Charsets.UTF_8);
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenWriteStringBuilderUsingFiles_thenWritten() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test.out");
+        final StringBuilder builder = new StringBuilder();
+        builder.append(expected_value);
+
+        Files.write(builder, file, Charsets.UTF_8);
+
+        final String result = Files.toString(file, Charsets.UTF_8);
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenWriteUsingCharSink_thenWritten() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test.out");
+        final CharSink sink = Files.asCharSink(file, Charsets.UTF_8);
+
+        sink.write(expected_value);
+
+        final String result = Files.toString(file, Charsets.UTF_8);
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenWriteMultipleLinesUsingCharSink_thenWritten() throws IOException {
+        final List<String> names = Lists.newArrayList("John", "Jane", "Adam", "Tom");
+        final File file = new File("src/test/resources/test.out");
+        final CharSink sink = Files.asCharSink(file, Charsets.UTF_8);
+
+        sink.writeLines(names, " ");
+
+        final String result = Files.toString(file, Charsets.UTF_8);
+        final String expected_value = Joiner.on(" ").join(names);
+        assertEquals(expected_value, result.trim());
+
+    }
+
+    @Test
+    public void whenWriteUsingByteSink_thenWritten() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test.out");
+        final ByteSink sink = Files.asByteSink(file);
+
+        sink.write(expected_value.getBytes());
+
+        final String result = Files.toString(file, Charsets.UTF_8);
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenReadUsingFiles_thenRead() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test1.in");
+
+        final String result = Files.toString(file, Charsets.UTF_8);
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenReadMultipleLinesUsingFiles_thenRead() throws IOException {
+        final File file = new File("src/test/resources/test2.in");
+
+        final List<String> result = Files.readLines(file, Charsets.UTF_8);
+        assertThat(result, contains("John", "Jane", "Adam", "Tom"));
+    }
+
+    @Test
+    public void whenReadUsingCharSource_thenRead() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test1.in");
+
+        final CharSource source = Files.asCharSource(file, Charsets.UTF_8);
+
+        final String result = source.read();
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenReadMultipleCharSources_thenRead() throws IOException {
+        final String expected_value = "Hello worldTest";
+        final File file1 = new File("src/test/resources/test1.in");
+        final File file2 = new File("src/test/resources/test1_1.in");
+
+        final CharSource source1 = Files.asCharSource(file1, Charsets.UTF_8);
+        final CharSource source2 = Files.asCharSource(file2, Charsets.UTF_8);
+        final CharSource source = CharSource.concat(source1, source2);
+
+        final String result = source.read();
+
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenReadUsingCharStream_thenRead() throws IOException {
+        final String expected_value = "Hello world";
+
+        final FileReader reader = new FileReader("src/test/resources/test1.in");
+        final String result = CharStreams.toString(reader);
+        reader.close();
+
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenReadUsingByteSource_thenRead() throws IOException {
+        final String expected_value = "Hello world";
+        final File file = new File("src/test/resources/test1.in");
+
+        final ByteSource source = Files.asByteSource(file);
+
+        final byte[] result = source.read();
+        assertEquals(expected_value, new String(result));
+    }
+
+    @Test
+    public void whenReadAfterOffsetUsingByteSource_thenRead() throws IOException {
+        final String expected_value = "lo world";
+        final File file = new File("src/test/resources/test1.in");
+
+        final long offset = 3;
+        final long length = 1000;
+        final ByteSource source = Files.asByteSource(file).slice(offset, length);
+
+        final byte[] result = source.read();
+        assertEquals(expected_value, new String(result));
+    }
+
+    @Test
+    public void whenReadUsingByteStream_thenRead() throws IOException {
+        final String expected_value = "Hello world";
+
+        final FileInputStream reader = new FileInputStream("src/test/resources/test1.in");
+        final byte[] result = ByteStreams.toByteArray(reader);
+        reader.close();
+
+        assertEquals(expected_value, new String(result));
+    }
+
+    @Test
+    public void whenReadUsingResources_thenRead() throws IOException {
+        final String expected_value = "Hello world";
+
+        final URL url = Resources.getResource("test1.in");
+        final String result = Resources.toString(url, Charsets.UTF_8);
+
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenCopyFileUsingFiles_thenCopied() throws IOException {
+        final String expected_value = "Hello world";
+
+        final File file1 = new File("src/test/resources/test1.in");
+        final File file2 = new File("src/test/resources/test_copy.in");
+
+        Files.copy(file1, file2);
+        final String result = Files.toString(file2, Charsets.UTF_8);
+
+        assertEquals(expected_value, result);
+    }
+
+    @Test
+    public void whenWriteReadLittleEndian_thenCorrect() throws IOException {
+        final int value = 100;
+
+        final LittleEndianDataOutputStream writer = new LittleEndianDataOutputStream(new FileOutputStream("src/test/resources/test_le.txt"));
+        writer.writeInt(value);
+        writer.close();
+
+        final LittleEndianDataInputStream reader = new LittleEndianDataInputStream(new DataInputStream(new FileInputStream("src/test/resources/test_le.txt")));
+        final int result = reader.readInt();
+        reader.close();
+
+        assertEquals(value, result);
+    }
+
+
+}
+
+//
+
+//
+//
+//
+//
+//
+

guava/src/test/resources/test1.in

@@ -0,0 +1 @@
+Hello world

guava/src/test/resources/test1_1.in

@@ -0,0 +1 @@
+Test

guava/src/test/resources/test2.in

@@ -0,0 +1,4 @@
+John
+Jane
+Adam
+Tom