Java Basic Archives - Page 10 of 13

Move file in Java

To migrate any file in Java, in Java 6 or older Java versions, we can use the renameTo() method located in the File object to do this:

package com.huongdanjava.javaexample;

import java.io.File;

public class MoveFile {

    public static void main(String[] args) {
        File source = new File("F://source.txt");
        File dest = new File("E://dest.txt");

        if (source.renameTo(dest)) {
            System.out.println("Move file " + source.getAbsolutePath() + " to " + dest.getAbsolutePath() + " success.");
        }
    }
}

package com.huongdanjava.javaexample;

import java.io.File;

public class MoveFile {

public static void main(String[] args) {

File source = new File("F://source.txt");

File dest = new File("E://dest.txt");

if (source.renameTo(dest)) {

System.out.println("Move file " + source.getAbsolutePath() + " to " + dest.getAbsolutePath() + " success.");

}

Result:

Move file F:\source.txt to E:\dest.txt success

1	Move file F:\source.txt to E:\dest.txt success

From Java 7 onwards, we have another way to move a file, which is to… Read More

In this tutorial, we will cover how to copy any file in Java. If you consider Java 6 or earlier, Java does not have an object or method that supports us copying a file, only creating or deleting a file. So if you are working… Read More

Delete file in Java

6 years ago by Khanh NguyenJava Basic

Even though creating a file in Java is easy, deleting a file is easier. In this tutorial, I will guide you how to delete a file in Java. The File object, which is the main file management object since Java version 6 and earlier, cannot be… Read More

Create file in Java

6 years ago by Khanh NguyenJava Basic

Creating files in Java is a basic operation, everyone must know. So, in this tutorial, I just synthesized the ways that we can create a file in Java. Maybe it is useful for beginners of Java programming. First, I have to mention the File object.… Read More

Some ways to initialize Optional object in Java

7 years ago by Khanh NguyenJava Basic

In the previous tutorial, I introduced with you all about the Optional object in Java. In this tutorial, let’s find out some ways to initialize your Optional object in Java. OK … First, we can initialize an Optional object with the nulled reference variable. For… Read More

Change Java version in macOS

7 years ago by Khanh NguyenJava Basic

Assume, you are installing multiple Java versions in macOS, so how do you change from one version to another? In this tutorial, I will guide you to do this. First, let’s open Terminal and enter the following command to check all the Java versions that… Read More

Method iterate() of Stream object in Java

7 years ago by Khanh NguyenJava Basic

In Java 8, the iterate() method has been introduced and it has only two parameters and will help us to create an infinite stream. Content:

public static<T> Stream<T> iterate(final T seed, final UnaryOperator<T> f)

1	public static<T> Stream<T> iterate(final T seed, final UnaryOperator<T> f)

Example:

package com.huongdanjava.javastream;

import java.util.stream.Stream;

public class Example {

	public static void main(String[] args) {
		Stream.iterate(1, i -> i + 1).forEach(System.out::println);
	}
}

package com.huongdanjava.javastream;

import java.util.stream.Stream;

public class Example {

public static void main(String[] args) {

Stream.iterate(1, i -> i + 1).forEach(System.out::println);

}

When running the above example, you will see that a Stream object contains endless numbers beginning at… Read More

Method ofNullable() of Stream object in Java

7 years ago by Khanh NguyenJava Basic

This method was added from Java 9.

static<T> Stream<T> ofNullable(T t)

1	static<T> Stream<T> ofNullable(T t)

This method will return the Stream object of an element in case this element is not null; if it is null, it returns an empty Stream. Example:

package com.huongdanjava.javaexample;

import java.util.stream.Stream;

public class Example {

	public static void main(String[] args) {
		String s = null;
		Stream.ofNullable(s).forEach(System.out::println);
	}
}

package com.huongdanjava.javaexample;

import java.util.stream.Stream;

public class Example {

public static void main(String[] args) {

String s = null;

Stream.ofNullable(s).forEach(System.out::println);

}

When you run the above code, it will print… Read More

Method dropWhile() of Stream object in Java

7 years ago by Khanh NguyenJava Basic

This method was added from Java 9.

default Stream<T> dropWhile(Predicate<? super T> predicate)

1	default Stream<T> dropWhile(Predicate<? super T> predicate)

This method also has the parameter Predicate interface and its function is the opposite of the takeWhile() method. This method also passes each element in your Stream object from left to right and ignores all elements that… Read More

Method takeWhile() of Stream object in Java

7 years ago by Khanh NguyenJava Basic

This method was added from Java 9.

default Stream<T> takeWhile(Predicate<? super T> predicate)

1	default Stream<T> takeWhile(Predicate<? super T> predicate)

The parameter of this method is the Predicate interface and this method takes the elements in your Stream object from left to right, until the condition of the Predicate object is no longer fulfilled. Example:

package com.huongdanjava.javastream;

import java.util.stream.Stream;

public class Example {

	public static void main(String[] args) {
		Stream.of(1,2,3,4,5,6,7,8,9,10)
			.takeWhile(i -> i < 5)
			.forEach(System.out::println);
	}
}

package com.huongdanjava.javastream;

import java.util.stream.Stream;

public class Example {

public static void main(String[] args) {

Stream.of(1,2,3,4,5,6,7,8,9,10)

.takeWhile(i -> i < 5)

.forEach(System.out::println);

}

In… Read More