네트워크 - 자원 정리(try-with-resources)

- CallException

public class CallException extends Exception {

    public CallException(String message) {
        super(message);
    }
}

 

- CloseException

public class CloseException extends Exception {

    public CloseException(String message) {
        super(message);
    }
}

 

- ResourceV2

AutoCloseable을 implements 하여 try-with-resources를 사용하자

public class ResourceV2 implements AutoCloseable {

    private String name;

    public ResourceV2(String name) {
        this.name = name;
    }

    public void call() {
        System.out.println(name + " call");
    }

    public void callEx() throws CallException {
        System.out.println(name + " callEx");
        throw new CallException(name + " ex");
    }

    @Override
    public void close() throws CloseException {
        System.out.println(name + " close");
        throw new CloseException(name + " ex");
    }

}

 

- ResurceCloseMainV4

public class ResourceCloseMainV4 {

    public static void main(String[] args) {
        try {
            logic();
        } catch (CallException e) {
            System.out.println("CallException 예외 처리");

            Throwable[] suppressed = e.getSuppressed();
            for (Throwable throwable : suppressed) {
                System.out.println("suppressedEx = " + throwable);
            }

            throw new RuntimeException(e);
        } catch (CloseException e) {
            System.out.println("CloseException 예외 처리");
            throw new RuntimeException(e);
        }
    }

    private static void logic() throws CallException, CloseException {
        try (ResourceV2 resource1 = new ResourceV2("resource1");
             ResourceV2 resource2 = new ResourceV2("resource2")) {

            resource1.call();
            resource2.callEx(); // CallException
        } catch (CallException e) {
            System.out.println("ex: " + e);
            throw e;
        }
    }
}

 

- 항상 try-with-resources를 사용할 수 있는 것은 아니다. 그렇지 않은 경우는 finally를 사용하여 처리해야한다.