Example: say I want to open a file. If I get a FileNotFoundException, I need to wait for some time and try again. How can I gracefully do that? Or do I need to use nested try/catch blocks?
Example :
public void openFile() {
File file = null;
try {
file = new <....>
} catch(FileNotFoundException e) {
}
return file;
}
You could use a do { ... } while (file == null) construct.
File file = null;
do {
try {
file = new <....>
} catch(FileNotFoundException e) {
// Wait for some time.
}
} while (file == null);
return file;
public File openFile() {
File file = null;
while (file == null) {
try {
file = new <....>
} catch(FileNotFoundException e) {
// Thread.sleep(waitingTime) or what you want to do
}
}
return file;
}
Note that this is a somewhat dangerous method, since there is no way to break out unless the file eventually appears. You could add a counter and give up after a certain number of tries, eg:
while (file == null) {
...
if (tries++ > MAX_TRIES) {
break;
}
}
public File openFile() {
File file = null;
while(true){
try {
file = new <....>
} catch(FileNotFoundException e) {
//wait for sometime
}
if(file!=null){
break;
}
}
return file;
}
