Here are 7 of the new features that have been completed:
- Language support for collections
- Automatic Resource Management
- Improved Type Inference for Generic Instance Creation (diamond)
- Underscores in numeric literals
- Strings in switch
- Binary literals
- Simplified Varargs Method Invocation
- There is a lot more to Java 7 then just these language changes. I’ll be exploring the rest of the release in future posts. One of the big debates is currently around
- Closures, which are a separate JSR.
- Language support for collections
Java will be getting first class language support for creating collections. The style change means that collections can be created like they are in Ruby, Perl etc.
Instead of:
- Κώδικας: Επιλογή όλων
List<String> list = new ArrayList<String>();
list.add("item");
String item = list.get(0);
Set<String> set = new HashSet<String>();
set.add("item");
Map<String, Integer> map = new HashMap<String, Integer>();
map.put("key", 1);
int value = map.get("key");
You will be able to use:
List<String> list = ["item"];
String item = list[0];
Set<String> set = {"item"};
Map<String, Integer> map = {"key" : 1};
int value = map["key"];
These collections are immutable.
Automatic Resource Management
Some resources in Java need to be closed manually like InputStream, Writers, Sockets, Sql classes. This language feature allows the try statement itself to declare one of more resources. These resources are scoped to the try block and are closed automatically.
This:
- Κώδικας: Επιλογή όλων
BufferedReader br = new BufferedReader(new FileReader(path));
try {
return br.readLine();
} finally {
br.close();
}
becomes:
try (BufferedReader br = new BufferedReader(new FileReader(path)) {
return br.readLine();
}
You can declare more than one resource to close:
