Java как удалить file
- Introduction to Java
- The complete History of Java Programming Language
- C++ vs Java vs Python
- How to Download and Install Java for 64 bit machine?
- Setting up the environment in Java
- How to Download and Install Eclipse on Windows?
- JDK in Java
- How JVM Works – JVM Architecture?
- Differences between JDK, JRE and JVM
- Just In Time Compiler
- Difference between JIT and JVM in Java
- Difference between Byte Code and Machine Code
- How is Java platform independent?
- Decision Making in Java (if, if-else, switch, break, continue, jump)
- Java if statement with Examples
- Java if-else
- Java if-else-if ladder with Examples
- Loops in Java
- For Loop in Java
- Java while loop with Examples
- Java do-while loop with Examples
- For-each loop in Java
- Continue Statement in Java
- Break statement in Java
- Usage of Break keyword in Java
- return keyword in Java
- Object Oriented Programming (OOPs) Concept in Java
- Why Java is not a purely Object-Oriented Language?
- Classes and Objects in Java
- Naming Conventions in Java
- Java Methods
- Access Modifiers in Java
- Java Constructors
- Four Main Object Oriented Programming Concepts of Java
- Inheritance in Java
- Abstraction in Java
- Encapsulation in Java
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- Interfaces in Java
- ‘this’ reference in Java
Java – Delete a File
The Kubernetes ecosystem is huge and quite complex, so it’s easy to forget about costs when trying out all of the exciting tools.
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We rely on other people’s code in our own work. Every day.
It might be the language you’re writing in, the framework you’re building on, or some esoteric piece of software that does one thing so well you never found the need to implement it yourself.
The problem is, of course, when things fall apart in production — debugging the implementation of a 3rd party library you have no intimate knowledge of is, to say the least, tricky.
Lightrun is a new kind of debugger.
It’s one geared specifically towards real-life production environments. Using Lightrun, you can drill down into running applications, including 3rd party dependencies, with real-time logs, snapshots, and metrics.
Learn more in this quick, 5-minute Lightrun tutorial:
Slow MySQL query performance is all too common. Of course it is. A good way to go is, naturally, a dedicated profiler that actually understands the ins and outs of MySQL.
The Jet Profiler was built for MySQL only, so it can do things like real-time query performance, focus on most used tables or most frequent queries, quickly identify performance issues and basically help you optimize your queries.
Critically, it has very minimal impact on your server’s performance, with most of the profiling work done separately — so it needs no server changes, agents or separate services.
Basically, you install the desktop application, connect to your MySQL server, hit the record button, and you’ll have results within minutes:
DbSchema is a super-flexible database designer, which can take you from designing the DB with your team all the way to safely deploying the schema.
The way it does all of that is by using a design model, a database-independent image of the schema, which can be shared in a team using GIT and compared or deployed on to any database.
And, of course, it can be heavily visual, allowing you to interact with the database using diagrams, visually compose queries, explore the data, generate random data, import data or build HTML5 database reports.
The Kubernetes ecosystem is huge and quite complex, so it’s easy to forget about costs when trying out all of the exciting tools.
To avoid overspending on your Kubernetes cluster, definitely have a look at the free K8s cost monitoring tool from the automation platform CAST AI. You can view your costs in real time, allocate them, calculate burn rates for projects, spot anomalies or spikes, and get insightful reports you can share with your team.
Connect your cluster and start monitoring your K8s costs right away:
We’re looking for a new Java technical editor to help review new articles for the site.
This quick article illustrates how to delete a File in Java – first using JDK 6, then JDK 7 and finally the Apache Commons IO library.
This article is part of the “Java – Back to Basic” series here on Baeldung.
1. With Java – JDK 6
Let’s start with the standard Java 6 solution:
@Test public void givenUsingJDK6_whenDeletingAFile_thenCorrect() throws IOException < new File("src/test/resources/fileToDelete_jdk6.txt").createNewFile(); File fileToDelete = new File("src/test/resources/fileToDelete_jdk6.txt"); boolean success = fileToDelete.delete(); assertTrue(success); >As you can see – the file must exist before the delete operation; if it doesn’t, the API will not throw any exceptions but will instead return false.
2. With Java – JDK 7
Let’s move on to the JDK 7 solution:
@Test public void givenUsingJDK7nio2_whenDeletingAFile_thenCorrect() throws IOException < Files.createFile(Paths.get("src/test/resources/fileToDelete_jdk7.txt")); Path fileToDeletePath = Paths.get("src/test/resources/fileToDelete_jdk7.txt"); Files.delete(fileToDeletePath); >Now – this will make better use of exceptions. If the file doesn’t exist when the delete operation is triggered – an NoSuchFileException will be thrown by the API:
java.nio.file.NoSuchFileException: srctestresourcesfileToDelete_jdk7.txt at s.n.f.WindowsException.translateToIOException(WindowsException.java:79)3. With Commons IO
Commons IO allows us to control the exceptions behavior when deleting a File. For a quiet delete that swallows any possible exceptions:
@Test public void givenUsingCommonsIo_whenDeletingAFileV1_thenCorrect() throws IOException < FileUtils.touch(new File("src/test/resources/fileToDelete_commonsIo.txt")); File fileToDelete = FileUtils.getFile("src/test/resources/fileToDelete_commonsIo.txt"); boolean success = FileUtils.deleteQuietly(fileToDelete); assertTrue(success); >Note that we can still determine if the operation was successful or not by simply checking the return value of the delete method.
Now – if we do want an exception to be thrown:
@Test public void givenUsingCommonsIo_whenDeletingAFileV2_thenCorrect() throws IOException < FileUtils.touch(new File("src/test/resources/fileToDelete.txt")); FileUtils.forceDelete(FileUtils.getFile("src/test/resources/fileToDelete.txt")); >If the file to be deleted doesn’t exist on the filesystem, the API will throw a standard FileNotFoundException:
java.io.FileNotFoundException: File does not exist: srctestresourcesfileToDelete.txt at org.apache.commons.io.FileUtils.forceDelete(FileUtils.java:2275)And there you have it – 4 simple ways to delete a File in Java.
Slow MySQL query performance is all too common. Of course it is. A good way to go is, naturally, a dedicated profiler that actually understands the ins and outs of MySQL.
The Jet Profiler was built for MySQL only, so it can do things like real-time query performance, focus on most used tables or most frequent queries, quickly identify performance issues and basically help you optimize your queries.
Critically, it has very minimal impact on your server’s performance, with most of the profiling work done separately — so it needs no server changes, agents or separate services.
Basically, you install the desktop application, connect to your MySQL server, hit the record button, and you’ll have results within minutes:
Как удалить файл
Удалить файл в Java можно несколькими способами: с помощью стандартного API и с помощью сторонних библиотек. В этой статье мы рассмотрим три способа:
- с помощью Files.delete
- с помощью Files.deleteIfExists
- с помощью FileUtils.deleteQuietly
Примечание 1: если вместо файла передан путь к директории, указанная директория будет удалена, если она пуста.
Примечание 2: если вместо файла указана символическая ссылка, она будет удалена, но файл не будет затронут.
Удаление файла с помощью Files.delete
Первый способ удалить файл – это воспользоваться стандартным методом Files.delete:
Стоит заметить, что метод Files.delete может генерировать исключения, поэтому его придётся завернуть в блок try-catch. Например, если указанный файл не найден, будет сгенерировано исключение NoSuchFileException .
Удаление файла с помощью Files.deleteIfExists
Следующий способ – использовать метод Files.deleteIfExists, который возвращает true или false в зависимости от того, получилось ли удалить указанный файл:
Также метод Files.deleteIfExists отличается от Files.delete тем, что не выбрасывает исключение NoSuchFileException в случае, если файл не найден.
Удаление файла с помощью FileUtils.deleteQuietly
Следующий способ – использовать библиотеку Commons IO. Для этого нужно подключить библиотеку в проект:
И воспользоваться методом FileUtils.deleteQuietly:
FileUtils.deleteQuietly(new File("/home/alex/test")); Этот метод не генерирует исключений в случае, если файл не найден или произошла другая ошибка при попытке удалить указанный файл.
Исходный код
import org.apache.commons.io.FileUtils; import java.io.File; import java.io.IOException; import java.nio.file.*; public class RemoveFile < public static void main(String[] args) < try < Files.delete(Paths.get("/home/alex/test")); >catch (IOException x) < System.err.println(x); >try < Files.deleteIfExists(Paths.get("/home/alex/test")); >catch (IOException e) < System.err.println(e); >FileUtils.deleteQuietly(new File("/home/alex/test")); > > Заключение
В данной статье мы рассмотрели различные способы для того, чтобы удалить файл. Вы можете воспользоваться любым исходя из ваших требований.