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Read files in java 8

Using FileInputStream and BufferedReader

Use this method when you want to read text from a character input stream. Buffering characters provides efficiency of the reading process.

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);
}
br.close();
} catch (FileNotFoundException e) {
// File not found
e.printStackTrace();
} catch (IOException e) {
// Error when reading the file
e.printStackTrace();
}

Using FileReader and BufferedReader

This example is similar the previous one, except the fact that we build the BufferedReader from a FileReader.

Use this option when you have to read character based content. You cannot specify the encoding charset for this method and it will use the platform encoding.

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);
}
br.close();
} catch (FileNotFoundException e) {
// File not found
e.printStackTrace();
} catch (IOException e) {
// Error when reading the file
e.printStackTrace();
}

Using Files.newBufferedReader() in Java 7 and above

This example is similar to the first one (Using FileInputStreamAND BufferedReader) . It uses the java.nio package and the try-with-resources exception management structure. It works starting from java 7.

// The required imports
import 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;
//The code
Path path = Paths.get("c:/tmp/myfile.csv");
Charset charset = Charset.forName("UTF-8");
try (BufferedReader reader = Files.newBufferedReader(path, charset)) {
String line = null;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}

Using Lambda expression in Java 8

One of the benefits of Lambda Expression is the reduction of the number of lines of code. In this example, we will read and print the content of a file in one line using Lambda Expressions and java.nio.file.Files class :

Files.lines(new File("c:/myfile.txt").toPath()).forEach(System.out::println);

(for simplicity I didnโ€™t include the exception management for the IOException exception)