Found 34494 Articles for Programming

What are final classes in Java?

Sreemaha
Updated on 30-Jul-2019 22:30:20

10K+ Views

The final modifier for finalizing the implementations of classes, methods, and variables. The main purpose of using a class being declared as final is to prevent the class from being subclassed. If a class is marked as final then no class can inherit any feature from the final class. You cannot extend a final class. If you try it gives you a compile time error. Example final class Super { private int data = 30; } public class Sub extends Super{ public static void main(String args[]){ } } Output ... Read More

What is meant by Java being platform-independent?

vanithasree
Updated on 30-Jul-2019 22:30:20

211 Views

When you compile Java programs using javac compiler it generates bytecode. We need to execute this bytecode using JVM (Java Virtual machine) Then, JVM translates the Java bytecode to machine understandable code.You can download JVM’s (comes along with JDK or JRE) suitable to your operating system and, once you write a Java program you can run it on any system using JVM.

How to close all the opened files using Python?

Rajendra Dharmkar
Updated on 17-Jul-2023 13:18:54

5K+ Views

In Python, file-handling tasks like opening, reading, writing, and closing files, or manipulating data in files are a common occurrence. While opening files has its significance and utility, it's equally important that files are closed properly to release system resources and to ensure that data integrity is maintained. In this article, we will explore different methods and techniques to close multiple opened files in Python, permitting you to optimize your file-handling operations and maintain clean code. Making Use of a Context Manager In Python, context managers are a tool for efficiently managing resources that need to be properly ... Read More

What is just-in-time or JIT compiler and what does it do?

radhakrishna
Updated on 30-Jul-2019 22:30:20

209 Views

Java uses javac (compiler) to convert the java code to byte code (.class file).Then, JVM internally converts the bytecode to system understandable code using an interpreter in addition to it JVM.Instead of executing a piece of code, again and again, JVM identifies them as “hot spots” and compiles them using Just in time compiler and, later reuses the same when required.

Difference between Java SE, Java EE, and Java ME?

mkotla
Updated on 30-Jul-2019 22:30:20

1K+ Views

Java provides three editions JSE, JEE, JME. JSE − Java Standard Edition using this, you can develop stand-alone applications. This provides the following packages − java.lang − This package provides the language basics. java.util − This package provides classes and interfaces (API’s) related to collection framework, events, data structure and other utility classes such as date. java.io − This package provides classes and interfaces for file operations, and other input and output operations. java.math − This package provides classes and interfaces for multiprecision arithmetics. java.nio − This package provides classes and interfaces the Non-blocking I/O framework for Java java.net ... Read More

How to change the root directory of the current process in Python?

Rajendra Dharmkar
Updated on 03-Oct-2019 06:21:11

1K+ Views

You can use the os.chroot to change the root directory of the current process to path. This command is only available on Unix systems. You can use it as follows:>>> import os >>> os.chroot('/tmp/my_folder')This changes the root directory of the script running to /tmp/my_folder.

How to change the user and group permissions for a directory using Python?

Rajendra Dharmkar
Updated on 13-Dec-2019 07:14:14

607 Views

You can change the owner of a file or a directory using the pwd, grp and os modules. The uid module is used to get the uid from user name, grp to get gid group name string and os to change the owner:Exampleimport pwd import grp import os uid = pwd.getpwnam("my_name").pw_uid gid = grp.getgrnam("my_group").gr_gid path = 'my_folder' os.chown(path, uid, gid)

How to find the version of Java using command line?

Giri Raju
Updated on 30-Jul-2019 22:30:20

11K+ Views

You can find the version of the Java software currently installed in your system using Programs and using Command prompt. Using Command prompt The -version command of the java command prompt gives you the current version of the Java software installed in your system. Therefore, open command prompt and type the command java -version to get the version of Java installed in your system. Using the Java program The System class of java.lang package provides a method named getProperty() this method accepts one of the following string parameters an returns the respective property. To get the version of the ... Read More

How to change the owner of a file using Python?

Rajendra Dharmkar
Updated on 13-Dec-2019 07:09:55

1K+ Views

You can change the owner of a file or a directory using the pwd, grp and os modules. The uid module is used to get the uid from user name, grp to get gid group name string and os to change the owner:Exampleimport pwd import grp import os uid = pwd.getpwnam("nobody").pw_uid gid = grp.getgrnam("nogroup").gr_gid path = 'my_folder' os.chown(path, uid, gid)

How to determine the OS the computer is running using Java?

Sreemaha
Updated on 30-Jul-2019 22:30:20

112 Views

The System class of java.lang package provides a method named getProperty() this method accepts one of the following string parameters an returns the respective property. java.class.path − If you pass this value as a parameter, the getProperty() method returns the current classpath. java.home − If you pass this value as a parameter, the getProperty() method returns the current Installation directory of the JRE. java.vendor − If you pass this value as a parameter, the getProperty() method returns the current vendor name of the JRE. java.vendor.url − If you pass this value as a parameter, the getProperty() method returns the ... Read More

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