Java: Try-Catch-Continue?

Let's say I can a set of statements:

try {
  String a = getProperty("a");
  String b = getProperty("b");
  String c = getProperty("c");
} catch(Exception e) {

}

Now, lets say property b was not found and the function throws an exception. In this case, how would I just continue or perhaps set b to null without having to write a try-catch block for each property? I mean, a,b,c exist but sometime th开发者_如何学Pythoney might not be found at all during which an exception is thrown.

Assuming you can't change the function so that it returns null when the property isn't found, you are kind of stuck wrapping everything in its own try catch block -- especially if you want for every value that can be retrieved to be retrieved (as opposed to letting the first value that fails cancel the whole operation.)

If you have a lot of these properties to retrieve, perhaps it would be cleaner to write a helper method to use:

String getPropertySafely(String key) {
   try {
      return getProperty(key);
   } catch (Exception e) {
      return null;
   }
}

You have to put a try-catch around each statement. There is no continue (like there is in ON ERROR ... RESUME blocks in VB). Instead of:

String a = null;
try {
  a = getProperty("a");
} catch(Exception e) {
  ...
}
String b = null;
try {
  b = getProperty("b");
} catch(Exception e) {
  ...
}
String c = null;
try {
  c = getProperty("c");
} catch(Exception e) {
  ...
}

you could write:

public String getPropertyNoException(String name) {
  try {
    return getProperty(name);
  } catch (Exception e) {
    return null;
  }
}

Personally I think a getProperty() is a poor candidate for throwing exceptions just for all this extra boilerplate required

Since you are using the same function each time you might be able to put this in a loop:

String[] abc = new String[3];
String[] param = {"a", "b", "c"};
for (int i = 0; i < 3; i++) {
    try {
      abc[i] = getProperty(param[i]);
    } catch(Exception e) {

    }
}

but this is rather contrived and would only be useful for a large number of properties. I suspect you will have to simple write 3 try-catch.

You should reconsider how getProperty is handled if you plan to use many of them because there isn't a plain way to do it.

You can exploit finally statement but you still need a try-catch for every call.