FileInputStream operation (#174)

* file operations * Formatted with Google Java Formatter Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

Author: realDuYuanChao

src/main/java/com/examplehub/basics/io/FileInputStreamExample.java

@@ -0,0 +1,44 @@
+package com.examplehub.basics.io;
+
+import java.io.*;
+
+public class FileInputStreamExample {
+ public static void readFile(String filename) throws IOException {
+ InputStream inputStream = null;
+ try {
+ inputStream = new FileInputStream(filename);
+ int read;
+ while ((read = inputStream.read()) != -1) {
+ System.out.print((char) read);
+ }
+ } catch (IOException e) {
+ e.printStackTrace();
+ } finally {
+ assert inputStream != null;
+ inputStream.close();
+ }
+ }
+
+ public static void readFileWithTryRecourse(String filename) throws FileNotFoundException {
+ try (InputStream inputStream = new FileInputStream(filename)) {
+ int read;
+ while ((read = inputStream.read()) != -1) {
+ System.out.print((char) read);
+ }
+ } catch (IOException e) {
+ e.printStackTrace();
+ }
+ }
+
+ public static void readFileWithBuffer(String filename) throws IOException {
+ try (InputStream inputStream = new FileInputStream(filename)) {
+ byte[] buffer = new byte[1024];
+ int readBytes;
+ while ((readBytes = inputStream.read(buffer)) != -1) {
+ for (int i = 0; i < readBytes; i++) {
+ System.out.print((char) buffer[i]);
+ }
+ }
+ }
+ }
+}

src/main/java/com/examplehub/basics/io/FileOutputStreamExample.java

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+package com.examplehub.basics.io;
+
+public class FileOutputStreamExample {}

src/main/java/com/examplehub/basics/io/ReadClasspathFile.java

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+package com.examplehub.basics.io;
+
+import java.io.InputStream;
+
+public class ReadClasspathFile {
+ public static void main(String[] args) {
+ InputStream inputStream = ReadClasspathFile.class.getResourceAsStream("default.properties");
+ System.out.println(inputStream);
+ }
+}

src/test/java/com/examplehub/basics/io/FileInputStreamExampleTest.java

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+package com.examplehub.basics.io;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import org.junit.jupiter.api.Test;
+
+class FileInputStreamExampleTest {
+ @Test
+ void testReadFile() throws IOException {
+ FileInputStreamExample.readFile("pom.xml");
+ }
+
+ @Test
+ void testReadFileWithTryRecourse() throws FileNotFoundException {
+ FileInputStreamExample.readFileWithTryRecourse("pom.xml");
+ }
+
+ @Test
+ void testReadFileWithBuffer() throws IOException {
+ FileInputStreamExample.readFileWithBuffer("pom.xml");
+ }
+}

src/test/java/com/examplehub/basics/io/FileOutputStreamExampleTest.java

@@ -0,0 +1,48 @@
+package com.examplehub.basics.io;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import com.examplehub.basics.file.DeleteFile;
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import org.junit.jupiter.api.Test;
+
+class FileOutputStreamExampleTest {
+ @Test
+ void testWriteByteToFile() throws IOException {
+ try (OutputStream outputStream = new FileOutputStream("temp.txt")) {
+ outputStream.write('H');
+ outputStream.write('e');
+ outputStream.write('l');
+ outputStream.write('l');
+ outputStream.write('o');
+ outputStream.flush();
+
+ assertTrue(new File("temp.txt").delete());
+ }
+ }
+
+ @Test
+ void testWriteString() throws IOException {
+ try (OutputStream outputStream = new FileOutputStream("temp.txt")) {
+ outputStream.write("Hello".getBytes(StandardCharsets.UTF_8));
+ assertTrue(new File("temp.txt").delete());
+ }
+ }
+
+ @Test
+ void testCopyFile() throws IOException {
+ String srcPath = "pom.xml";
+ String destPath = "pom.xml.bk";
+ try (InputStream inputStream = new FileInputStream(srcPath);
+ OutputStream outputStream = new FileOutputStream(destPath)) {
+ byte[] bytes = new byte[1024];
+ int readBytes;
+ while ((readBytes = inputStream.read(bytes)) != -1) {
+ outputStream.write(bytes, 0, readBytes);
+ }
+ }
+
+ assertTrue(DeleteFile.deleteFile("pom.xml.bk"));
+ }
+}