try (FileInputStream fis = new FileInputStream("source.txt");
     BufferedInputStream bis = new BufferedInputStream(fis);
     FileOutputStream fos = new FileOutputStream("dest.txt");
     BufferedOutputStream bos = new BufferedOutputStream(fos)) {
    
    byte[] buffer = new byte[8192];
    int bytesRead;
    while ((bytesRead = bis.read(buffer)) != -1) {
        bos.write(buffer, 0, bytesRead);
    }
}

// Псевдокод трансформации компилятором
{
    final Resource r1 = new Resource("r1");
    Throwable primaryExc1 = null;
    try {
        final Resource r2 = new Resource("r2");
        Throwable primaryExc2 = null;
        try {
            // Основной блок
            r1.work();
            r2.work();
        } catch (Throwable t) {
            primaryExc2 = t;
            throw t;
        } finally {
            if (r2 != null) {
                if (primaryExc2 != null) {
                    try {
                        r2.close();
                    } catch (Throwable suppressed) {
                        primaryExc2.addSuppressed(suppressed);
                    }
                } else {
                    r2.close();
                }
            }
        }
    } catch (Throwable t) {
        primaryExc1 = t;
        throw t;
    } finally {
        if (r1 != null) {
            if (primaryExc1 != null) {
                try {
                    r1.close();
                } catch (Throwable suppressed) {
                    primaryExc1.addSuppressed(suppressed);
                }
            } else {
                r1.close();
            }
        }
    }
}

try (FileReader fr = new FileReader("file.txt");
     BufferedReader br = new BufferedReader(fr)) {
    // ...
}
// Закрытие: br.close() вызывает fr.close(), затем fr.close() вызывается повторно

public List<User> findUsersByRole(String role) throws SQLException {
    String query = "SELECT id, name, email FROM users WHERE role = ?";
    
    try (Connection conn = dataSource.getConnection();
         PreparedStatement stmt = conn.prepareStatement(query);
         ResultSet rs = stmt.executeQuery()) {
        
        stmt.setString(1, role);
        List<User> users = new ArrayList<>();
        
        while (rs.next()) {
            users.add(mapRowToUser(rs));
        }
        return users;
    }
}

// Java 7/8: избыточное объявление новой переменной
BufferedReader br = new BufferedReader(new FileReader("data.txt"));
try (BufferedReader reader = br) {  // Вынуждены создать reader, хотя br уже готов
    String line = reader.readLine();
    // ...
}

// Java 9+: прямое использование существующей переменной
BufferedReader br = new BufferedReader(new FileReader("data.txt"));
try (br) {  // Нет необходимости в новой переменной
    String line = br.readLine();
    // ...
}

// Java 9+: несколько effectively final ресурсов
final Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery(query);  // effectively final

try (statement; resultSet) {
    while (resultSet.next()) {
        processRow(resultSet);
    }
}

public class ReportGenerator {
    
    public void generateMonthlyReport(Path outputPath) throws IOException {
        // Ресурс создается здесь
        BufferedWriter writer = Files.newBufferedWriter(outputPath);
        
        try {
            writeHeader(writer);
            writeBody(writer);
            writeFooter(writer);
        } finally {
            // Ручное закрытие до Java 9
            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException e) {
                    logger.warn("Failed to close writer", e);
                }
            }
        }
    }
}

public void generateMonthlyReport(Path outputPath) throws IOException {
    BufferedWriter writer = Files.newBufferedWriter(outputPath);
    
    try (writer) {
        writeHeader(writer);
        writeBody(writer);
        writeFooter(writer);
    }
    // writer автоматически закрыт, suppressed exceptions сохранены
}

// Потенциально опасный код с effectively final
Resource r1 = new Resource("r1");
Resource r2 = new Resource("r2");  // Если здесь исключение — r1 не будет закрыт!

try (r1; r2) {
    // ...
}

Connection conn = dataSource.getConnection();
PreparedStatement stmt = conn.prepareStatement(query);
ResultSet rs = stmt.executeQuery();

try (conn; stmt; rs) {
    return extractResults(rs);
} catch (SQLException e) {
    // Выполняется после закрытия всех ресурсов
    throw new DataAccessException("Query failed: " + query, e);
} finally {
    // Выполняется после catch, все ресурсы уже закрыты
    metrics.recordQueryExecution(query, System.currentTimeMillis() - startTime);
}

import java.io.*;

public class Task240426 {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new StringReader("test"));

        try (reader) {
            System.out.print(reader.readLine());
        }

        reader.readLine();
    }
}