In Java 8, reading files can be accomplished through several methods, each suited to different scenarios. Whether you’re dealing with large text files, need to handle character encoding, or prefer more modern approaches like lambda expressions, Java 8 provides the flexibility to do so efficiently. Below, we’ll explore various techniques to read files in Java 8, with code examples and explanations.

1. Using FileInputStream and BufferedReader

This method is useful when you need to read text from a character input stream, especially when dealing with raw binary files. Buffering characters with BufferedReader enhances the efficiency of the reading process.

Example:

javaCopy codeimport java.io.*;

File file = new File("myFile.zip");

try (FileInputStream fis = new FileInputStream(file);
     BufferedReader br = new BufferedReader(new InputStreamReader(fis))) {
     
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println(line);
    }
} catch (FileNotFoundException e) {
    // File not found
    e.printStackTrace();
} catch (IOException e) {
    // Error when reading the file
    e.printStackTrace();
}

2. Using FileReader and BufferedReade

This approach is similar to the previous one, but here we use FileReader instead of FileInputStream. FileReader is specifically designed for reading character files. However, it uses the platform’s default charset, so if you need to specify a different charset, consider using InputStreamReader.

Example:

javaCopy codeimport java.io.*;

File file = new File("myFile.txt");

try (BufferedReader br = new BufferedReader(new FileReader(file))) {
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println(line);
    }
} catch (FileNotFoundException e) {
    // File not found
    e.printStackTrace();
} catch (IOException e) {
    // Error when reading the file
    e.printStackTrace();
}

---

3. Using Files.newBufferedReader() in Java 7 and Above

Introduced in Java 7, the java.nio.file.Files class provides several static methods for file operations. Files.newBufferedReader() is similar to the previous methods but allows specifying the character encoding, and it integrates seamlessly with the try-with-resources statement for better resource management.

Example:

javaCopy codeimport java.io.BufferedReader;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

Path path = Paths.get("c:/tmp/myfile.csv");
Charset charset = Charset.forName("UTF-8");

try (BufferedReader reader = Files.newBufferedReader(path, charset)) {
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    e.printStackTrace();
}

4. Using Lambda Expressions in Java 8

Lambda expressions, introduced in Java 8, can significantly reduce the amount of boilerplate code. In this example, we read and print the content of a file in a single line using the Files.lines() method combined with a lambda expression.

Example:

javaCopy codeimport java.io.File;
import java.io.IOException;
import java.nio.file.Files;

try {
    Files.lines(new File("c:/myfile.txt").toPath())
         .forEach(System.out::println);
} catch (IOException e) {
    e.printStackTrace();
}

---

Conclusion

Java 8 provides a range of methods for reading files, each with its own use case. Whether you prefer the classic approach with FileInputStream and BufferedReader, or more modern techniques like Files.newBufferedReader() and lambda expressions, Java 8 has you covered. Always choose the method that best suits your needs, considering factors like file size, character encoding, and code readability.