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 expectedValue = "Hello world";
final File file = new File("src/test/resources/test.out");
Files.write(expectedValue, file, Charsets.UTF_8);
final String result = Files.toString(file, Charsets.UTF_8);
assertEquals(expectedValue, result);
}
@Test
public void whenWriteUsingCharSink_thenWritten() throws IOException {
final String expectedValue = "Hello world";
final File file = new File("src/test/resources/test.out");
final CharSink sink = Files.asCharSink(file, Charsets.UTF_8);
sink.write(expectedValue);
final String result = Files.toString(file, Charsets.UTF_8);
assertEquals(expectedValue, 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 expectedValue = Joiner.on(" ").join(names);
assertEquals(expectedValue, result.trim());
}
@Test
public void whenWriteUsingByteSink_thenWritten() throws IOException {
final String expectedValue = "Hello world";
final File file = new File("src/test/resources/test.out");
final ByteSink sink = Files.asByteSink(file);
sink.write(expectedValue.getBytes());
final String result = Files.toString(file, Charsets.UTF_8);
assertEquals(expectedValue, result);
}
@Test
public void whenReadUsingFiles_thenRead() throws IOException {
final String expectedValue = "Hello world";
final File file = new File("src/test/resources/test1.in");
final String result = Files.toString(file, Charsets.UTF_8);
assertEquals(expectedValue, 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 expectedValue = "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(expectedValue, result);
}
@Test
public void whenReadMultipleCharSources_thenRead() throws IOException {
final String expectedValue = "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(expectedValue, result);
}
@Test
public void whenReadUsingCharStream_thenRead() throws IOException {
final String expectedValue = "Hello world";
final FileReader reader = new FileReader("src/test/resources/test1.in");
final String result = CharStreams.toString(reader);
assertEquals(expectedValue, result);
reader.close();
}
@Test
public void whenReadUsingByteSource_thenRead() throws IOException {
final String expectedValue = "Hello world";
final File file = new File("src/test/resources/test1.in");
final ByteSource source = Files.asByteSource(file);
final byte[] result = source.read();
assertEquals(expectedValue, new String(result));
}
@Test
public void whenReadAfterOffsetUsingByteSource_thenRead() throws IOException {
final String expectedValue = "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(expectedValue, new String(result));
}
@Test
public void whenReadUsingByteStream_thenRead() throws IOException {
final String expectedValue = "Hello world";
final FileInputStream reader = new FileInputStream("src/test/resources/test1.in");
final byte[] result = ByteStreams.toByteArray(reader);
assertEquals(expectedValue, new String(result));
reader.close();
}
@Test
public void whenReadUsingResources_thenRead() throws IOException {
final String expectedValue = "Hello world";
final URL url = Resources.getResource("test1.in");
final String result = Resources.toString(url, Charsets.UTF_8);
assertEquals(expectedValue, result);
}
@Test
public void whenCopyFileUsingFiles_thenCopied() throws IOException {
final String expectedValue = "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(expectedValue, 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);
}
}