The example reads the first line from a file. It uses an instance of BufferedReader
to read data from the file. BufferedReader
is a resource that must be closed after the program is finished with it:
static String readFirstLineFromFile(String path) throws IOException {
try (BufferedReader br = new BufferedReader(new FileReader(path))) {
return br.readLine();
}
}
In this example, the resource declared in the try-with-resources statement is a BufferedReader
. The declaration statement appears within parentheses immediately after the try keyword. The class BufferedReader
, in Java SE 7 and later, implements the interface java.lang.AutoCloseable
. Because the BufferedReader
instance is declared in a try-with-resource statement, it will be closed regardless of whether the try statement completes normally or abruptly (as a result of the method BufferedReader.readLine
throwing an IOException
).