Add Java-io-2
This commit is contained in:
parent
e21d6d2e93
commit
a68493c2ec
|
|
@ -0,0 +1,5 @@
|
|||
0.*
|
||||
|
||||
# Files generated by integration tests
|
||||
# *.txt
|
||||
/temp
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
## Core Java IO
|
||||
|
||||
This module contains articles about core Java input and output (IO)
|
||||
|
||||
### Relevant Articles:
|
||||
- [Create a File in a Specific Directory in Java](https://www.baeldung.com/java-create-file-in-directory)
|
||||
- [How to Read a Large File Efficiently with Java](https://www.baeldung.com/java-read-lines-large-file)
|
||||
- [Java – Write to File](https://www.baeldung.com/java-write-to-file)
|
||||
- [FileNotFoundException in Java](https://www.baeldung.com/java-filenotfound-exception)
|
||||
- [Delete the Contents of a File in Java](https://www.baeldung.com/java-delete-file-contents)
|
||||
- [List Files in a Directory in Java](https://www.baeldung.com/java-list-directory-files)
|
||||
- [Java – Append Data to a File](https://www.baeldung.com/java-append-to-file)
|
||||
- [How to Copy a File with Java](https://www.baeldung.com/java-copy-file)
|
||||
- [Create a Directory in Java](https://www.baeldung.com/java-create-directory)
|
||||
- [Java IO vs NIO](https://www.baeldung.com/java-io-vs-nio)
|
||||
- [[<-- Prev]](/core-java-modules/core-java-io)[[More -->]](/core-java-modules/core-java-io-3)
|
||||
|
|
@ -0,0 +1,70 @@
|
|||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<project xmlns="http://maven.apache.org/POM/4.0.0"
|
||||
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||||
<modelVersion>4.0.0</modelVersion>
|
||||
<artifactId>core-java-io-2</artifactId>
|
||||
<version>${project.parent.version}</version>
|
||||
<name>core-java-io-2</name>
|
||||
<packaging>jar</packaging>
|
||||
|
||||
<parent>
|
||||
<groupId>com.ossez.core-java-modules</groupId>
|
||||
<artifactId>core-java-modules</artifactId>
|
||||
<version>0.0.2-SNAPSHOT</version>
|
||||
<relativePath>../pom.xml</relativePath>
|
||||
</parent>
|
||||
|
||||
<dependencies>
|
||||
<!-- utils -->
|
||||
<dependency>
|
||||
<groupId>commons-io</groupId>
|
||||
<artifactId>commons-io</artifactId>
|
||||
<version>${commons-io.version}</version>
|
||||
</dependency>
|
||||
<!-- logging -->
|
||||
<dependency>
|
||||
<groupId>log4j</groupId>
|
||||
<artifactId>log4j</artifactId>
|
||||
<version>${log4j.version}</version>
|
||||
</dependency>
|
||||
<dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
|
||||
<groupId>org.slf4j</groupId>
|
||||
<artifactId>log4j-over-slf4j</artifactId>
|
||||
<version>${log4j-over-slf4j.version}</version>
|
||||
</dependency>
|
||||
<!-- https://mvnrepository.com/artifact/com.github.tomakehurst/wiremock -->
|
||||
<dependency>
|
||||
<groupId>com.github.tomakehurst</groupId>
|
||||
<artifactId>wiremock</artifactId>
|
||||
<version>${wiremock.version}</version>
|
||||
<scope>test</scope>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
|
||||
<build>
|
||||
<finalName>core-java-io-2</finalName>
|
||||
<resources>
|
||||
<resource>
|
||||
<directory>src/main/resources</directory>
|
||||
<filtering>true</filtering>
|
||||
</resource>
|
||||
</resources>
|
||||
<plugins>
|
||||
<plugin>
|
||||
<groupId>org.apache.maven.plugins</groupId>
|
||||
<artifactId>maven-javadoc-plugin</artifactId>
|
||||
<version>${maven-javadoc-plugin.version}</version>
|
||||
<configuration>
|
||||
<source>11</source>
|
||||
</configuration>
|
||||
</plugin>
|
||||
</plugins>
|
||||
</build>
|
||||
|
||||
<properties>
|
||||
<maven-javadoc-plugin.version>3.3.2</maven-javadoc-plugin.version>
|
||||
<wiremock.version>2.26.3</wiremock.version>
|
||||
</properties>
|
||||
|
||||
</project>
|
||||
|
|
@ -0,0 +1,66 @@
|
|||
package com.ossez.listfiles;
|
||||
|
||||
import java.io.File;
|
||||
import java.io.IOException;
|
||||
import java.nio.file.*;
|
||||
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 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> listFilesUsingFilesList(String dir) throws IOException {
|
||||
try (Stream<Path> stream = Files.list(Paths.get(dir))) {
|
||||
return stream
|
||||
.filter(file -> !Files.isDirectory(file))
|
||||
.map(Path::getFileName)
|
||||
.map(Path::toString)
|
||||
.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) {
|
||||
if (!Files.isDirectory(file)) {
|
||||
fileList.add(file.getFileName().toString());
|
||||
}
|
||||
return FileVisitResult.CONTINUE;
|
||||
}
|
||||
});
|
||||
return fileList;
|
||||
}
|
||||
|
||||
public Set<String> listFilesUsingDirectoryStream(String dir) throws IOException {
|
||||
Set<String> fileSet = new HashSet<>();
|
||||
try (DirectoryStream<Path> stream = Files.newDirectoryStream(Paths.get(dir))) {
|
||||
for (Path path : stream) {
|
||||
if (!Files.isDirectory(path)) {
|
||||
fileSet.add(path.getFileName().toString());
|
||||
}
|
||||
}
|
||||
}
|
||||
return fileSet;
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,12 @@
|
|||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<configuration scan="true" scanPeriod="15 seconds" debug="false">
|
||||
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
|
||||
<encoder>
|
||||
<pattern>[%d{ISO8601}]-[%thread] %-5level %logger - %msg%n</pattern>
|
||||
</encoder>
|
||||
</appender>
|
||||
|
||||
<root level="WARN">
|
||||
<appender-ref ref="STDOUT" />
|
||||
</root>
|
||||
</configuration>
|
||||
|
|
@ -0,0 +1,80 @@
|
|||
package com.ossez.appendtofile;
|
||||
|
||||
import static org.assertj.core.api.Assertions.assertThat;
|
||||
|
||||
import java.io.BufferedWriter;
|
||||
import java.io.File;
|
||||
import java.io.FileInputStream;
|
||||
import java.io.FileOutputStream;
|
||||
import java.io.FileWriter;
|
||||
import java.io.IOException;
|
||||
import java.io.PrintWriter;
|
||||
import java.nio.charset.StandardCharsets;
|
||||
import java.nio.file.Files;
|
||||
import java.nio.file.Paths;
|
||||
import java.nio.file.StandardOpenOption;
|
||||
|
||||
import com.google.common.base.Charsets;
|
||||
import com.google.common.io.CharSink;
|
||||
import com.google.common.io.FileWriteMode;
|
||||
import org.apache.commons.io.FileUtils;
|
||||
import org.junit.After;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
public class AppendToFileManualTest {
|
||||
|
||||
public static final String fileName = "src/main/resources/countries.properties";
|
||||
|
||||
@Before
|
||||
@After
|
||||
public void setup() throws Exception {
|
||||
PrintWriter writer = new PrintWriter(fileName);
|
||||
writer.print("UK\r\n" + "US\r\n" + "Germany\r\n");
|
||||
writer.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenAppendToFileUsingGuava_thenCorrect() throws IOException {
|
||||
File file = new File(fileName);
|
||||
CharSink chs = com.google.common.io.Files.asCharSink(file, Charsets.UTF_8, FileWriteMode.APPEND);
|
||||
chs.write("Spain\r\n");
|
||||
|
||||
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenAppendToFileUsingFiles_thenCorrect() throws IOException {
|
||||
Files.write(Paths.get(fileName), "Spain\r\n".getBytes(), StandardOpenOption.APPEND);
|
||||
|
||||
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenAppendToFileUsingFileUtils_thenCorrect() throws IOException {
|
||||
File file = new File(fileName);
|
||||
FileUtils.writeStringToFile(file, "Spain\r\n", StandardCharsets.UTF_8, true);
|
||||
|
||||
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenAppendToFileUsingFileOutputStream_thenCorrect() throws Exception {
|
||||
FileOutputStream fos = new FileOutputStream(fileName, true);
|
||||
fos.write("Spain\r\n".getBytes());
|
||||
fos.close();
|
||||
|
||||
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenAppendToFileUsingFileWriter_thenCorrect() throws IOException {
|
||||
FileWriter fw = new FileWriter(fileName, true);
|
||||
BufferedWriter bw = new BufferedWriter(fw);
|
||||
bw.write("Spain");
|
||||
bw.newLine();
|
||||
bw.close();
|
||||
|
||||
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
package com.ossez.appendtofile;
|
||||
|
||||
import org.apache.commons.io.IOUtils;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.io.InputStream;
|
||||
import java.io.StringWriter;
|
||||
|
||||
public class StreamUtils {
|
||||
|
||||
public static String getStringFromInputStream(InputStream input) throws IOException {
|
||||
StringWriter writer = new StringWriter();
|
||||
IOUtils.copy(input, writer, "UTF-8");
|
||||
return writer.toString();
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,52 @@
|
|||
package com.ossez.blockingnonblocking;
|
||||
|
||||
import com.github.tomakehurst.wiremock.junit.WireMockRule;
|
||||
import org.junit.Before;
|
||||
import org.junit.Rule;
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.*;
|
||||
import java.net.Socket;
|
||||
|
||||
import static com.github.tomakehurst.wiremock.client.WireMock.*;
|
||||
import static com.github.tomakehurst.wiremock.core.WireMockConfiguration.wireMockConfig;
|
||||
import static org.junit.Assert.assertTrue;
|
||||
|
||||
public class BlockingClientUnitTest {
|
||||
private static final String REQUESTED_RESOURCE = "/test.json";
|
||||
|
||||
@Rule public WireMockRule wireMockRule = new WireMockRule(wireMockConfig().dynamicPort());
|
||||
|
||||
@Before
|
||||
public void setup() {
|
||||
stubFor(get(urlEqualTo(REQUESTED_RESOURCE)).willReturn(aResponse()
|
||||
.withStatus(200)
|
||||
.withBody("{ \"response\" : \"It worked!\" }\r\n\r\n")));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenJavaIOSocket_whenReadingAndWritingWithStreams_thenSuccess() throws IOException {
|
||||
// given an IO socket and somewhere to store our result
|
||||
Socket socket = new Socket("localhost", wireMockRule.port());
|
||||
StringBuilder ourStore = new StringBuilder();
|
||||
|
||||
// when we write and read (using try-with-resources so our resources are auto-closed)
|
||||
try (InputStream serverInput = socket.getInputStream();
|
||||
BufferedReader reader = new BufferedReader(new InputStreamReader(serverInput));
|
||||
OutputStream clientOutput = socket.getOutputStream();
|
||||
PrintWriter writer = new PrintWriter(new OutputStreamWriter(clientOutput))) {
|
||||
writer.print("GET " + REQUESTED_RESOURCE + " HTTP/1.0\r\n\r\n");
|
||||
writer.flush(); // important - without this the request is never sent, and the test will hang on readLine()
|
||||
|
||||
for (String line; (line = reader.readLine()) != null; ) {
|
||||
ourStore.append(line);
|
||||
ourStore.append(System.lineSeparator());
|
||||
}
|
||||
}
|
||||
|
||||
// then we read and saved our data
|
||||
assertTrue(ourStore
|
||||
.toString()
|
||||
.contains("It worked!"));
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,94 @@
|
|||
package com.ossez.blockingnonblocking;
|
||||
|
||||
import com.github.tomakehurst.wiremock.junit.WireMockRule;
|
||||
import org.junit.Before;
|
||||
import org.junit.Rule;
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.net.InetSocketAddress;
|
||||
import java.nio.ByteBuffer;
|
||||
import java.nio.CharBuffer;
|
||||
import java.nio.channels.SocketChannel;
|
||||
import java.nio.charset.Charset;
|
||||
import java.nio.charset.CharsetDecoder;
|
||||
import java.nio.charset.StandardCharsets;
|
||||
|
||||
import static com.github.tomakehurst.wiremock.client.WireMock.*;
|
||||
import static com.github.tomakehurst.wiremock.core.WireMockConfiguration.wireMockConfig;
|
||||
import static org.junit.Assert.assertTrue;
|
||||
|
||||
public class NonBlockingClientUnitTest {
|
||||
private String REQUESTED_RESOURCE = "/test.json";
|
||||
|
||||
@Rule public WireMockRule wireMockRule = new WireMockRule(wireMockConfig().dynamicPort());
|
||||
|
||||
@Before
|
||||
public void setup() {
|
||||
stubFor(get(urlEqualTo(REQUESTED_RESOURCE)).willReturn(aResponse()
|
||||
.withStatus(200)
|
||||
.withBody("{ \"response\" : \"It worked!\" }")));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenJavaNIOSocketChannel_whenReadingAndWritingWithBuffers_thenSuccess() throws IOException {
|
||||
// given a NIO SocketChannel and a charset
|
||||
InetSocketAddress address = new InetSocketAddress("localhost", wireMockRule.port());
|
||||
SocketChannel socketChannel = SocketChannel.open(address);
|
||||
Charset charset = StandardCharsets.UTF_8;
|
||||
|
||||
// when we write and read using buffers
|
||||
socketChannel.write(charset.encode(CharBuffer.wrap("GET " + REQUESTED_RESOURCE + " HTTP/1.0\r\n\r\n")));
|
||||
|
||||
ByteBuffer byteBuffer = ByteBuffer.allocate(8192); // or allocateDirect if we need direct memory access
|
||||
CharBuffer charBuffer = CharBuffer.allocate(8192);
|
||||
CharsetDecoder charsetDecoder = charset.newDecoder();
|
||||
StringBuilder ourStore = new StringBuilder();
|
||||
while (socketChannel.read(byteBuffer) != -1 || byteBuffer.position() > 0) {
|
||||
byteBuffer.flip();
|
||||
storeBufferContents(byteBuffer, charBuffer, charsetDecoder, ourStore);
|
||||
byteBuffer.compact();
|
||||
}
|
||||
socketChannel.close();
|
||||
|
||||
// then we read and saved our data
|
||||
assertTrue(ourStore
|
||||
.toString()
|
||||
.contains("It worked!"));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenJavaNIOSocketChannel_whenReadingAndWritingWithSmallBuffers_thenSuccess() throws IOException {
|
||||
// given a NIO SocketChannel and a charset
|
||||
InetSocketAddress address = new InetSocketAddress("localhost", wireMockRule.port());
|
||||
SocketChannel socketChannel = SocketChannel.open(address);
|
||||
Charset charset = StandardCharsets.UTF_8;
|
||||
|
||||
// when we write and read using buffers that are too small for our message
|
||||
socketChannel.write(charset.encode(CharBuffer.wrap("GET " + REQUESTED_RESOURCE + " HTTP/1.0\r\n\r\n")));
|
||||
|
||||
ByteBuffer byteBuffer = ByteBuffer.allocate(8); // or allocateDirect if we need direct memory access
|
||||
CharBuffer charBuffer = CharBuffer.allocate(8);
|
||||
CharsetDecoder charsetDecoder = charset.newDecoder();
|
||||
StringBuilder ourStore = new StringBuilder();
|
||||
while (socketChannel.read(byteBuffer) != -1 || byteBuffer.position() > 0) {
|
||||
byteBuffer.flip();
|
||||
storeBufferContents(byteBuffer, charBuffer, charsetDecoder, ourStore);
|
||||
byteBuffer.compact();
|
||||
}
|
||||
socketChannel.close();
|
||||
|
||||
// then we read and saved our data
|
||||
assertTrue(ourStore
|
||||
.toString()
|
||||
.contains("It worked!"));
|
||||
}
|
||||
|
||||
void storeBufferContents(ByteBuffer byteBuffer, CharBuffer charBuffer, CharsetDecoder charsetDecoder, StringBuilder ourStore) {
|
||||
charsetDecoder.decode(byteBuffer, charBuffer, true);
|
||||
charBuffer.flip();
|
||||
ourStore.append(charBuffer);
|
||||
charBuffer.clear();
|
||||
}
|
||||
|
||||
}
|
||||
|
|
@ -0,0 +1,69 @@
|
|||
package com.ossez.copyfiles;
|
||||
|
||||
import java.io.BufferedInputStream;
|
||||
import java.io.BufferedOutputStream;
|
||||
import java.io.File;
|
||||
import java.io.FileInputStream;
|
||||
import java.io.FileOutputStream;
|
||||
import java.io.IOException;
|
||||
import java.io.InputStream;
|
||||
import java.io.OutputStream;
|
||||
import java.nio.file.Files;
|
||||
import java.nio.file.Path;
|
||||
import java.nio.file.Paths;
|
||||
import java.nio.file.StandardCopyOption;
|
||||
|
||||
import org.apache.commons.io.FileUtils;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
import static org.assertj.core.api.Assertions.*;
|
||||
|
||||
public class FileCopierIntegrationTest {
|
||||
File original = new File("src/test/resources/original.txt");
|
||||
|
||||
@Before
|
||||
public void init() throws IOException {
|
||||
if (!original.exists())
|
||||
Files.createFile(original.toPath());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenIoAPI_whenCopied_thenCopyExistsWithSameContents() throws IOException {
|
||||
File copied = new File("src/test/resources/copiedWithIo.txt");
|
||||
try (InputStream in = new BufferedInputStream(new FileInputStream(original)); OutputStream out = new BufferedOutputStream(new FileOutputStream(copied))) {
|
||||
byte[] buffer = new byte[1024];
|
||||
int lengthRead;
|
||||
while ((lengthRead = in.read(buffer)) > 0) {
|
||||
out.write(buffer, 0, lengthRead);
|
||||
out.flush();
|
||||
}
|
||||
}
|
||||
assertThat(copied).exists();
|
||||
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenCommonsIoAPI_whenCopied_thenCopyExistsWithSameContents() throws IOException {
|
||||
File copied = new File("src/test/resources/copiedWithApacheCommons.txt");
|
||||
FileUtils.copyFile(original, copied);
|
||||
assertThat(copied).exists();
|
||||
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenNIO2_whenCopied_thenCopyExistsWithSameContents() throws IOException {
|
||||
Path copied = Paths.get("src/test/resources/copiedWithNio.txt");
|
||||
Path originalPath = original.toPath();
|
||||
Files.copy(originalPath, copied, StandardCopyOption.REPLACE_EXISTING);
|
||||
assertThat(copied).exists();
|
||||
assertThat(Files.readAllLines(originalPath).equals(Files.readAllLines(copied)));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenGuava_whenCopied_thenCopyExistsWithSameContents() throws IOException {
|
||||
File copied = new File("src/test/resources/copiedWithApacheCommons.txt");
|
||||
com.google.common.io.Files.copy(original, copied);
|
||||
assertThat(copied).exists();
|
||||
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,60 @@
|
|||
package com.ossez.createfiles;
|
||||
|
||||
import com.google.common.io.Files;
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.File;
|
||||
import java.io.IOException;
|
||||
import org.junit.BeforeClass;
|
||||
import static org.junit.Assert.assertFalse;
|
||||
import static org.junit.Assert.assertTrue;
|
||||
|
||||
public class CreateFilesUnitTest {
|
||||
|
||||
@BeforeClass
|
||||
public static void clean() {
|
||||
File tempDirectory = new File(System.getProperty("java.io.tmpdir"));
|
||||
File file1 = new File(tempDirectory.getAbsolutePath() + "/testFile.txt");
|
||||
File file2 = new File(tempDirectory, "newFile.txt");
|
||||
File file3 = new File(tempDirectory.getAbsolutePath() + File.separator + "newFile2.txt");
|
||||
file1.delete();
|
||||
file2.delete();
|
||||
file3.delete();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAnExistingDirectory_whenCreatingAFileWithAbsolutePath_thenFileIsCreated() throws IOException {
|
||||
File tempDirectory = new File(System.getProperty("java.io.tmpdir"));
|
||||
File fileWithAbsolutePath = new File(tempDirectory.getAbsolutePath() + "/testFile.txt");
|
||||
|
||||
assertFalse(fileWithAbsolutePath.exists());
|
||||
|
||||
Files.touch(fileWithAbsolutePath);
|
||||
|
||||
assertTrue(fileWithAbsolutePath.exists());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAnExistingDirectory_whenCreatingANewDirectoryAndFileWithRelativePath_thenFileIsCreated() throws IOException {
|
||||
File tempDirectory = new File(System.getProperty("java.io.tmpdir"));
|
||||
File fileWithRelativePath = new File(tempDirectory, "newFile.txt");
|
||||
|
||||
assertFalse(fileWithRelativePath.exists());
|
||||
|
||||
Files.touch(fileWithRelativePath);
|
||||
|
||||
assertTrue(fileWithRelativePath.exists());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenCreatingAFileWithFileSeparator_thenFileIsCreated() throws IOException {
|
||||
File tempDirectory = new File(System.getProperty("java.io.tmpdir"));
|
||||
File newFile = new File(tempDirectory.getAbsolutePath() + File.separator + "newFile2.txt");
|
||||
|
||||
assertFalse(newFile.exists());
|
||||
|
||||
Files.touch(newFile);
|
||||
|
||||
assertTrue(newFile.exists());
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,94 @@
|
|||
package com.ossez.deletecontents;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertEquals;
|
||||
|
||||
import java.io.BufferedWriter;
|
||||
import java.io.File;
|
||||
import java.io.FileInputStream;
|
||||
import java.io.FileOutputStream;
|
||||
import java.io.FileWriter;
|
||||
import java.io.IOException;
|
||||
import java.io.PrintWriter;
|
||||
import java.nio.channels.FileChannel;
|
||||
import java.nio.charset.Charset;
|
||||
import java.nio.file.Files;
|
||||
import java.nio.file.Paths;
|
||||
import java.nio.file.StandardOpenOption;
|
||||
|
||||
import org.apache.commons.io.FileUtils;
|
||||
import org.junit.After;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
public class FilesClearDataUnitTest {
|
||||
|
||||
public static final String FILE_PATH = "src/test/resources/fileexample.txt";
|
||||
|
||||
@Before
|
||||
@After
|
||||
public void setup() throws IOException {
|
||||
PrintWriter writer = new PrintWriter(FILE_PATH);
|
||||
writer.print("This example shows how we can delete the file contents without deleting the file");
|
||||
writer.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingPrintWritter_thenEmptyFile() throws IOException {
|
||||
PrintWriter writer = new PrintWriter(FILE_PATH);
|
||||
writer.print("");
|
||||
writer.close();
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingPrintWritterWithougObject_thenEmptyFile() throws IOException {
|
||||
new PrintWriter(FILE_PATH).close();
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingFileWriter_thenEmptyFile() throws IOException {
|
||||
new FileWriter(FILE_PATH, false).close();
|
||||
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingFileOutputStream_thenEmptyFile() throws IOException {
|
||||
new FileOutputStream(FILE_PATH).close();
|
||||
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingFileUtils_thenEmptyFile() throws IOException {
|
||||
FileUtils.write(new File(FILE_PATH), "", Charset.defaultCharset());
|
||||
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingNIOFiles_thenEmptyFile() throws IOException {
|
||||
BufferedWriter writer = Files.newBufferedWriter(Paths.get(FILE_PATH));
|
||||
writer.write("");
|
||||
writer.flush();
|
||||
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingNIOFileChannel_thenEmptyFile() throws IOException {
|
||||
FileChannel.open(Paths.get(FILE_PATH), StandardOpenOption.WRITE).truncate(0).close();
|
||||
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingFile_whenDeleteContentUsingGuava_thenEmptyFile() throws IOException {
|
||||
File file = new File(FILE_PATH);
|
||||
byte[] empty = new byte[0];
|
||||
com.google.common.io.Files.write(empty, file);
|
||||
|
||||
assertEquals(0, StreamUtils.getStringFromInputStream(new FileInputStream(FILE_PATH)).length());
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
package com.ossez.deletecontents;
|
||||
|
||||
import org.apache.commons.io.IOUtils;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.io.InputStream;
|
||||
import java.io.StringWriter;
|
||||
|
||||
public class StreamUtils {
|
||||
|
||||
public static String getStringFromInputStream(InputStream input) throws IOException {
|
||||
StringWriter writer = new StringWriter();
|
||||
IOUtils.copy(input, writer, "UTF-8");
|
||||
return writer.toString();
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,100 @@
|
|||
package com.ossez.directories;
|
||||
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.File;
|
||||
|
||||
import static org.junit.Assert.assertFalse;
|
||||
import static org.junit.Assert.assertTrue;
|
||||
|
||||
public class NewDirectoryUnitTest {
|
||||
|
||||
private static final File TEMP_DIRECTORY = new File(System.getProperty("java.io.tmpdir"));
|
||||
|
||||
@Before
|
||||
public void beforeEach() {
|
||||
File newDirectory = new File(TEMP_DIRECTORY, "new_directory");
|
||||
File nestedInNewDirectory = new File(newDirectory, "nested_directory");
|
||||
File existingDirectory = new File(TEMP_DIRECTORY, "existing_directory");
|
||||
File existingNestedDirectory = new File(existingDirectory, "existing_nested_directory");
|
||||
File nestedInExistingDirectory = new File(existingDirectory, "nested_directory");
|
||||
|
||||
nestedInNewDirectory.delete();
|
||||
newDirectory.delete();
|
||||
nestedInExistingDirectory.delete();
|
||||
existingDirectory.mkdir();
|
||||
existingNestedDirectory.mkdir();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenUnexistingDirectory_whenMkdir_thenTrue() {
|
||||
File newDirectory = new File(TEMP_DIRECTORY, "new_directory");
|
||||
assertFalse(newDirectory.exists());
|
||||
|
||||
boolean directoryCreated = newDirectory.mkdir();
|
||||
|
||||
assertTrue(directoryCreated);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingDirectory_whenMkdir_thenFalse() {
|
||||
File newDirectory = new File(TEMP_DIRECTORY, "new_directory");
|
||||
newDirectory.mkdir();
|
||||
assertTrue(newDirectory.exists());
|
||||
|
||||
boolean directoryCreated = newDirectory.mkdir();
|
||||
|
||||
assertFalse(directoryCreated);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenUnexistingNestedDirectories_whenMkdir_thenFalse() {
|
||||
File newDirectory = new File(TEMP_DIRECTORY, "new_directory");
|
||||
File nestedDirectory = new File(newDirectory, "nested_directory");
|
||||
assertFalse(newDirectory.exists());
|
||||
assertFalse(nestedDirectory.exists());
|
||||
|
||||
boolean directoriesCreated = nestedDirectory.mkdir();
|
||||
|
||||
assertFalse(directoriesCreated);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenUnexistingNestedDirectories_whenMkdirs_thenTrue() {
|
||||
File newDirectory = new File(System.getProperty("java.io.tmpdir") + File.separator + "new_directory");
|
||||
File nestedDirectory = new File(newDirectory, "nested_directory");
|
||||
assertFalse(newDirectory.exists());
|
||||
assertFalse(nestedDirectory.exists());
|
||||
|
||||
boolean directoriesCreated = nestedDirectory.mkdirs();
|
||||
|
||||
assertTrue(directoriesCreated);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingParentDirectories_whenMkdirs_thenTrue() {
|
||||
File newDirectory = new File(TEMP_DIRECTORY, "existing_directory");
|
||||
newDirectory.mkdir();
|
||||
File nestedDirectory = new File(newDirectory, "nested_directory");
|
||||
assertTrue(newDirectory.exists());
|
||||
assertFalse(nestedDirectory.exists());
|
||||
|
||||
boolean directoriesCreated = nestedDirectory.mkdirs();
|
||||
|
||||
assertTrue(directoriesCreated);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenExistingNestedDirectories_whenMkdirs_thenFalse() {
|
||||
File existingDirectory = new File(TEMP_DIRECTORY, "existing_directory");
|
||||
File existingNestedDirectory = new File(existingDirectory, "existing_nested_directory");
|
||||
assertTrue(existingDirectory.exists());
|
||||
assertTrue(existingNestedDirectory.exists());
|
||||
|
||||
boolean directoriesCreated = existingNestedDirectory.mkdirs();
|
||||
|
||||
assertFalse(directoriesCreated);
|
||||
}
|
||||
|
||||
}
|
||||
|
|
@ -0,0 +1,58 @@
|
|||
package com.ossez.filenotfoundexception;
|
||||
|
||||
import org.junit.Test;
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
|
||||
import java.io.*;
|
||||
|
||||
public class FileNotFoundExceptionUnitTest {
|
||||
|
||||
private static final Logger LOG = LoggerFactory.getLogger(FileNotFoundExceptionUnitTest.class);
|
||||
|
||||
private String fileName = Double.toString(Math.random());
|
||||
|
||||
@Test(expected = BusinessException.class)
|
||||
public void raiseBusinessSpecificException() throws IOException {
|
||||
try {
|
||||
readFailingFile();
|
||||
} catch (FileNotFoundException ex) {
|
||||
throw new BusinessException("BusinessException: necessary file was not present.");
|
||||
}
|
||||
}
|
||||
|
||||
@Test
|
||||
public void createFile() throws IOException {
|
||||
try {
|
||||
readFailingFile();
|
||||
} catch (FileNotFoundException ex) {
|
||||
try {
|
||||
new File(fileName).createNewFile();
|
||||
readFailingFile();
|
||||
} catch (IOException ioe) {
|
||||
throw new RuntimeException("BusinessException: even creation is not possible.");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@Test
|
||||
public void logError() throws IOException {
|
||||
try {
|
||||
readFailingFile();
|
||||
} catch (FileNotFoundException ex) {
|
||||
LOG.error("Optional file " + fileName + " was not found.");
|
||||
}
|
||||
}
|
||||
|
||||
private void readFailingFile() throws IOException {
|
||||
BufferedReader rd = new BufferedReader(new FileReader(new File(fileName)));
|
||||
rd.readLine();
|
||||
// no need to close file
|
||||
}
|
||||
|
||||
private class BusinessException extends RuntimeException {
|
||||
BusinessException(String string) {
|
||||
super(string);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,71 @@
|
|||
package com.ossez.listfiles;
|
||||
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.util.Collections;
|
||||
import java.util.HashSet;
|
||||
import java.util.Set;
|
||||
|
||||
import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
|
||||
import static org.junit.Assert.assertEquals;
|
||||
import static org.junit.jupiter.api.Assertions.assertThrows;
|
||||
|
||||
public class ListFilesUnitTest {
|
||||
|
||||
private static final String VALID_DIRECTORY = "src/test/resources/listFilesUnitTestFolder";
|
||||
private static final String INVALID_DIRECTORY = "src/test/resources/thisDirectoryDoesNotExist";
|
||||
private static final Set<String> EXPECTED_FILE_SET = new HashSet<String>() {
|
||||
{
|
||||
add("test.xml");
|
||||
add("employee.json");
|
||||
add("students.json");
|
||||
add("country.txt");
|
||||
}
|
||||
};
|
||||
private static final int DEPTH = 1;
|
||||
private final ListFiles listFiles = new ListFiles();
|
||||
|
||||
@Test
|
||||
public void givenAValidDirectoryWhenUsingJavaIOThenReturnSetOfFileNames() {
|
||||
assertThat(listFiles.listFilesUsingJavaIO(VALID_DIRECTORY))
|
||||
.isEqualTo(EXPECTED_FILE_SET);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAInvalidValidDirectoryWhenUsingJavaIOThenThrowsNullPointerExceptino() {
|
||||
assertThrows(NullPointerException.class,
|
||||
() -> listFiles.listFilesUsingJavaIO(INVALID_DIRECTORY));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAValidDirectoryWhenUsingFilesListThenReturnSetOfFileNames() throws IOException {
|
||||
assertThat(listFiles.listFilesUsingFilesList(VALID_DIRECTORY))
|
||||
.isEqualTo(EXPECTED_FILE_SET);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAValidDirectoryWhenUsingFilesWalkWithDepth1ThenReturnSetOfFileNames() throws IOException {
|
||||
assertThat(listFiles.listFilesUsingFileWalk(VALID_DIRECTORY, DEPTH))
|
||||
.isEqualTo(EXPECTED_FILE_SET);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAValidDirectoryWhenUsingFilesWalkFileTreeThenReturnSetOfFileNames() throws IOException {
|
||||
assertThat(listFiles.listFilesUsingFileWalkAndVisitor(VALID_DIRECTORY))
|
||||
.isEqualTo(EXPECTED_FILE_SET);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAValidDirectoryWhenUsingDirectoryStreamThenReturnSetOfFileNames() throws IOException {
|
||||
assertThat(listFiles.listFilesUsingDirectoryStream(VALID_DIRECTORY))
|
||||
.isEqualTo(EXPECTED_FILE_SET);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenAValidFileWhenUsingFilesWalkWithDepth1ThenReturnSetOfTheSameFile() throws IOException {
|
||||
Set<String> expectedFileSet = Collections.singleton("test.xml");
|
||||
String filePathString = "src/test/resources/listFilesUnitTestFolder/test.xml";
|
||||
assertEquals(expectedFileSet, listFiles.listFilesUsingFileWalk(filePathString, DEPTH));
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,107 @@
|
|||
package com.ossez.readlargefile;
|
||||
|
||||
import java.io.File;
|
||||
import java.io.FileInputStream;
|
||||
import java.io.IOException;
|
||||
import java.util.Scanner;
|
||||
|
||||
import org.apache.commons.io.FileUtils;
|
||||
import org.apache.commons.io.LineIterator;
|
||||
import org.junit.Ignore;
|
||||
import org.junit.Test;
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
|
||||
import com.google.common.base.Charsets;
|
||||
import com.google.common.io.Files;
|
||||
|
||||
@Ignore("need large file for testing")
|
||||
public class ReadLargeFileUnitTest {
|
||||
protected final Logger logger = LoggerFactory.getLogger(getClass());
|
||||
|
||||
// tests - iterate lines in a file
|
||||
|
||||
@Test
|
||||
public final void givenUsingGuava_whenIteratingAFile_thenCorrect() throws IOException {
|
||||
final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
|
||||
// final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
|
||||
|
||||
logMemory();
|
||||
Files.readLines(new File(path), Charsets.UTF_8);
|
||||
logMemory();
|
||||
}
|
||||
|
||||
@Test
|
||||
public final void givenUsingCommonsIo_whenIteratingAFileInMemory_thenCorrect() throws IOException {
|
||||
// final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
|
||||
final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
|
||||
|
||||
logMemory();
|
||||
FileUtils.readLines(new File(path));
|
||||
logMemory();
|
||||
}
|
||||
|
||||
@Test
|
||||
public final void whenStreamingThroughAFile_thenCorrect() throws IOException {
|
||||
final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
|
||||
// final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
|
||||
|
||||
logMemory();
|
||||
|
||||
FileInputStream inputStream = null;
|
||||
Scanner sc = null;
|
||||
try {
|
||||
inputStream = new FileInputStream(path);
|
||||
sc = new Scanner(inputStream, "UTF-8");
|
||||
while (sc.hasNextLine()) {
|
||||
final String line = sc.nextLine();
|
||||
// System.out.println(line);
|
||||
}
|
||||
// note that Scanner suppresses exceptions
|
||||
if (sc.ioException() != null) {
|
||||
throw sc.ioException();
|
||||
}
|
||||
} finally {
|
||||
if (inputStream != null) {
|
||||
inputStream.close();
|
||||
}
|
||||
if (sc != null) {
|
||||
sc.close();
|
||||
}
|
||||
}
|
||||
|
||||
logMemory();
|
||||
}
|
||||
|
||||
@Test
|
||||
public final void givenUsingApacheIo_whenStreamingThroughAFile_thenCorrect() throws IOException {
|
||||
final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
|
||||
// final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
|
||||
|
||||
logMemory();
|
||||
|
||||
final LineIterator it = FileUtils.lineIterator(new File(path), "UTF-8");
|
||||
try {
|
||||
while (it.hasNext()) {
|
||||
final String line = it.nextLine();
|
||||
// do something with line
|
||||
}
|
||||
} finally {
|
||||
LineIterator.closeQuietly(it);
|
||||
}
|
||||
|
||||
logMemory();
|
||||
}
|
||||
|
||||
// utils
|
||||
|
||||
private final void logMemory() {
|
||||
logger.info("Max Memory: {} Mb", Runtime.getRuntime()
|
||||
.maxMemory() / 1048576);
|
||||
logger.info("Total Memory: {} Mb", Runtime.getRuntime()
|
||||
.totalMemory() / 1048576);
|
||||
logger.info("Free Memory: {} Mb", Runtime.getRuntime()
|
||||
.freeMemory() / 1048576);
|
||||
}
|
||||
|
||||
}
|
||||
|
|
@ -0,0 +1,193 @@
|
|||
package com.ossez.writetofile;
|
||||
|
||||
import static org.junit.Assert.assertEquals;
|
||||
|
||||
import java.io.BufferedOutputStream;
|
||||
import java.io.BufferedReader;
|
||||
import java.io.BufferedWriter;
|
||||
import java.io.DataInputStream;
|
||||
import java.io.DataOutputStream;
|
||||
import java.io.File;
|
||||
import java.io.FileInputStream;
|
||||
import java.io.FileOutputStream;
|
||||
import java.io.FileReader;
|
||||
import java.io.FileWriter;
|
||||
import java.io.IOException;
|
||||
import java.io.PrintWriter;
|
||||
import java.io.RandomAccessFile;
|
||||
import java.nio.ByteBuffer;
|
||||
import java.nio.channels.FileChannel;
|
||||
import java.nio.channels.FileLock;
|
||||
import java.nio.channels.OverlappingFileLockException;
|
||||
import java.nio.charset.Charset;
|
||||
import java.nio.file.Files;
|
||||
import java.nio.file.Path;
|
||||
import java.nio.file.Paths;
|
||||
|
||||
import org.junit.Test;
|
||||
|
||||
public class JavaWriteToFileUnitTest {
|
||||
|
||||
private String fileNameLarge = "src/test/resources/test_large.txt";
|
||||
private String fileName = "src/test/resources/test_write.txt";
|
||||
private String fileName1 = "src/test/resources/test_write_1.txt";
|
||||
private String fileName2 = "src/test/resources/test_write_2.txt";
|
||||
private String fileName3 = "src/test/resources/test_write_3.txt";
|
||||
private String fileName4 = "src/test/resources/test_write_4.txt";
|
||||
private String fileName5 = "src/test/resources/test_write_5.txt";
|
||||
|
||||
@Test
|
||||
public void whenWriteStringUsingBufferedWritter_thenCorrect() throws IOException {
|
||||
final String str = "Hello";
|
||||
final BufferedWriter writer = new BufferedWriter(new FileWriter(fileName3));
|
||||
writer.write(str);
|
||||
writer.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenAppendStringUsingBufferedWritter_thenOldContentShouldExistToo() throws IOException {
|
||||
final String str = "World";
|
||||
final BufferedWriter writer = new BufferedWriter(new FileWriter(fileName3, true));
|
||||
writer.append(' ');
|
||||
writer.append(str);
|
||||
writer.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenWritingStringToFile_whenUsingPrintWriter_thenCorrect() throws IOException {
|
||||
final FileWriter fileWriter = new FileWriter(fileName);
|
||||
final PrintWriter printWriter = new PrintWriter(fileWriter);
|
||||
printWriter.print("Some String");
|
||||
printWriter.printf("Product name is %s and its price is %d $", "iPhone", 1000);
|
||||
printWriter.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenWritingStringToFile_whenUsingFileOutputStream_thenCorrect() throws IOException {
|
||||
final String str = "Hello";
|
||||
final FileOutputStream outputStream = new FileOutputStream(fileName3);
|
||||
final byte[] strToBytes = str.getBytes();
|
||||
outputStream.write(strToBytes);
|
||||
outputStream.close();
|
||||
}
|
||||
|
||||
//
|
||||
|
||||
@Test
|
||||
public void givenWritingToFile_whenUsingDataOutputStream_thenCorrect() throws IOException {
|
||||
final String value = "Hello";
|
||||
final FileOutputStream fos = new FileOutputStream(fileName1);
|
||||
final DataOutputStream outStream = new DataOutputStream(new BufferedOutputStream(fos));
|
||||
outStream.writeUTF(value);
|
||||
outStream.close();
|
||||
|
||||
String result;
|
||||
final FileInputStream fis = new FileInputStream(fileName1);
|
||||
final DataInputStream reader = new DataInputStream(fis);
|
||||
result = reader.readUTF();
|
||||
reader.close();
|
||||
|
||||
assertEquals(value, result);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenWritingToSpecificPositionInFile_thenCorrect() throws IOException {
|
||||
final int data1 = 2014;
|
||||
final int data2 = 1500;
|
||||
writeToPosition(fileName2, data1, 4);
|
||||
assertEquals(data1, readFromPosition(fileName2, 4));
|
||||
writeToPosition(fileName2, data2, 4);
|
||||
assertEquals(data2, readFromPosition(fileName2, 4));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenTryToLockFile_thenItShouldBeLocked() throws IOException {
|
||||
final RandomAccessFile stream = new RandomAccessFile(fileName4, "rw");
|
||||
final FileChannel channel = stream.getChannel();
|
||||
|
||||
FileLock lock = null;
|
||||
try {
|
||||
lock = channel.tryLock();
|
||||
} catch (final OverlappingFileLockException e) {
|
||||
stream.close();
|
||||
channel.close();
|
||||
}
|
||||
stream.writeChars("test lock");
|
||||
lock.release();
|
||||
|
||||
stream.close();
|
||||
channel.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenWritingToFile_whenUsingFileChannel_thenCorrect() throws IOException {
|
||||
final RandomAccessFile stream = new RandomAccessFile(fileName5, "rw");
|
||||
final FileChannel channel = stream.getChannel();
|
||||
final String value = "Hello";
|
||||
final byte[] strBytes = value.getBytes();
|
||||
final ByteBuffer buffer = ByteBuffer.allocate(strBytes.length);
|
||||
buffer.put(strBytes);
|
||||
buffer.flip();
|
||||
channel.write(buffer);
|
||||
stream.close();
|
||||
channel.close();
|
||||
|
||||
final RandomAccessFile reader = new RandomAccessFile(fileName5, "r");
|
||||
assertEquals(value, reader.readLine());
|
||||
reader.close();
|
||||
|
||||
}
|
||||
|
||||
@Test
|
||||
public void writingToLargeFile() throws IOException {
|
||||
final RandomAccessFile stream = new RandomAccessFile(fileNameLarge, "rw");
|
||||
stream.setLength(1024 * 1024 * 1024);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenWriteToTmpFile_thenCorrect() throws IOException {
|
||||
final String toWrite = "Hello";
|
||||
final File tmpFile = File.createTempFile("test", ".tmp");
|
||||
final FileWriter writer = new FileWriter(tmpFile);
|
||||
writer.write(toWrite);
|
||||
writer.close();
|
||||
|
||||
final BufferedReader reader = new BufferedReader(new FileReader(tmpFile));
|
||||
assertEquals(toWrite, reader.readLine());
|
||||
reader.close();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenUsingJava7_whenWritingToFile_thenCorrect() throws IOException {
|
||||
final String str = "Hello";
|
||||
|
||||
final Path path = Paths.get(fileName3);
|
||||
final byte[] strToBytes = str.getBytes();
|
||||
|
||||
Files.write(path, strToBytes);
|
||||
|
||||
final String read = Files.readAllLines(path, Charset.defaultCharset()).get(0);
|
||||
assertEquals(str, read);
|
||||
}
|
||||
|
||||
// UTIL
|
||||
|
||||
// use RandomAccessFile to write data at specific position in the file
|
||||
private void writeToPosition(final String filename, final int data, final long position) throws IOException {
|
||||
final RandomAccessFile writer = new RandomAccessFile(filename, "rw");
|
||||
writer.seek(position);
|
||||
writer.writeInt(data);
|
||||
writer.close();
|
||||
}
|
||||
|
||||
// use RandomAccessFile to read data from specific position in the file
|
||||
private int readFromPosition(final String filename, final long position) throws IOException {
|
||||
int result = 0;
|
||||
final RandomAccessFile reader = new RandomAccessFile(filename, "r");
|
||||
reader.seek(position);
|
||||
result = reader.readInt();
|
||||
reader.close();
|
||||
return result;
|
||||
}
|
||||
|
||||
}
|
||||
|
|
@ -0,0 +1,3 @@
|
|||
UK
|
||||
US
|
||||
Germany
|
||||
|
|
@ -0,0 +1 @@
|
|||
This example shows how we can delete the file contents without deleting the file
|
||||
|
|
@ -0,0 +1 @@
|
|||
This is a sample txt file for unit test ListFilesUnitTest
|
||||
|
|
@ -0,0 +1 @@
|
|||
{}
|
||||
|
|
@ -0,0 +1 @@
|
|||
{}
|
||||
|
|
@ -0,0 +1 @@
|
|||
<xml></xml>
|
||||
|
|
@ -0,0 +1 @@
|
|||
Some StringProduct name is iPhone and its price is 1000 $
|
||||
Binary file not shown.
Binary file not shown.
|
|
@ -0,0 +1 @@
|
|||
Hello World
|
||||
Binary file not shown.
Loading…
Reference in New Issue