//: c10:Cleanup.java // From 'Thinking in Java, 2nd ed.' by Bruce Eckel // www.BruceEckel.com. See copyright notice in CopyRight.txt. // Paying attention to exceptions // in constructors. import java.io.*; class InputFile { private BufferedReader in; InputFile(String fname) throws Exception { try { in = new BufferedReader( new FileReader(fname)); // Other code that might throw exceptions } catch(FileNotFoundException e) { System.err.println( "Could not open " + fname); // Wasn't open, so don't close it throw e; } catch(Exception e) { // All other exceptions must close it try { in.close(); } catch(IOException e2) { System.err.println( "in.close() unsuccessful"); } throw e; // Rethrow } finally { // Don't close it here!!! } } String getLine() { String s; try { s = in.readLine(); } catch(IOException e) { System.err.println( "readLine() unsuccessful"); s = "failed"; } return s; } void cleanup() { try { in.close(); } catch(IOException e2) { System.err.println( "in.close() unsuccessful"); } } } public class Cleanup { public static void main(String[] args) { try { InputFile in = new InputFile("Cleanup.java"); String s; int i = 1; while((s = in.getLine()) != null) System.out.println(""+ i++ + ": " + s); in.cleanup(); } catch(Exception e) { System.err.println( "Caught in main, e.printStackTrace()"); e.printStackTrace(System.err); } } } ///:~