What is try with resource in Java? Example tutorial

In Java we normally use resources like file, network connection, socket connection, database connection etc ,dealing with resources is not a difficult task but what if after using the resources programmers forget to close the resources. As we know in Java everything is Object so if we forget to close or shut down the resource its responsibility of GC that will recollect it when its no longer used but we can reduce resource exhaustion by explicitly closing the resources as soon we done with our job with the resources. Some resources like database connection are very precious and would surely run out of resources if waited for finalization. Many database servers only accept a certain number of connections so if forget to close properly will create problem.

 
So JDK 7 come with the solution of try with resource also called automatic resource management where when try block ended automatically it will close or release our resource. Let see one example how to use try with resource in JDK 7

The try-with-resources statement is a feature introduced in Java 7. It simplifies the resource management and improves the code readability by automatically closing the resources that are opened in a try block. In this article, we will learn how to use try-with-resources in Java to handle resources like file streams, database connections, and network sockets. We will also discuss the benefits of using try-with-resources over traditional try-catch-finally blocks.

How to Use try with resource in Java - JDK 7

Here's an example of using try with resources in Java

public void readFile(String fileName) throws IOException {
    try (FileReader fileReader = new FileReader(fileName);
         BufferedReader bufferedReader = new BufferedReader(fileReader)) {
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            System.out.println(line);
        }
    }
}

In this example, we're reading from a file using a FileReader and a BufferedReader. Instead of manually closing these resources, we're using try with resources to automatically close them once the block of code inside the try statement completes. This helps to ensure that the resources are properly released and avoids potential resource leaks.

Here is another example of using try-with-resource statement in Java:

Difference between try-with-resource and try-catch-finally pattern in Java

Yes, there are several benefits of using the try-with-resources statement over the traditional try-catch-finally block:

1. Simplified Code

The try-with-resources statement simplifies code by reducing the number of lines required to create, use, and close a resource.

2. Automatic Resource Management

When a try block is exited, the resources are automatically closed. There is no need to explicitly close the resources, reducing the risk of resource leaks.

3. Exception Handling
The try-with-resources statement ensures that any exceptions thrown when closing resources are handled correctly. If an exception is thrown when closing a resource, it will be suppressed, and any exceptions thrown in the try block will still be thrown.

4. Support for Multiple Resources

The try-with-resources statement supports managing multiple resources in a single statement, further simplifying code and reducing the chance of errors.

Overall, the try-with-resources statement is a significant improvement over the traditional try-catch-finally block when dealing with resources in Java. It is more concise, less error-prone, and handles exceptions more efficiently. Though you must note that your resource must implement AutoCloseable interface in order to be used inside try-with-resource statement. This concept is also frequently tested on Java interviews. 

That's all about what is try with resource in Java and how to use it for automatica resource management in Java. The try-with-resources statement in Java simplifies the process of handling resources by eliminating the need for explicit finally blocks. This reduces the amount of code and makes it easier to read and maintain. 

Additionally, it ensures that resources are always properly closed, even in the presence of exceptions. The try-with-resources statement is a great addition to Java 7 and is highly recommended for use in any code that deals with resources such as files, sockets, and database connections.