Java 7's Best New Features

Java 6 is approaching its end of life release in February 2013, so here are some new features of Java 7 that will help you hit the ground running with the new JDK. A few of them are sure to be huge timesavers, like using Strings in switch statements.

Binary Literals

int j = 0b10101010101;

Underscores in Numbers

Let you quickly see how large a number really is.

int k = 1_000_000;

String Switch Statements

Use the new string switch statements to apply .equals() on the string:

switch(someString)
{
    case "Saturday": case "Sunday": 
        return "weekend";

    default:
        return "weekday";
}

Automatic Resource Closing

When you open streams in try blocks, they are now automatically closed.

try(InputStream in = socket.getInputStream();
    PrintStream out = new PrintStream(new BufferedOutputStream(socket.getOutputStream())))
{
    byte[] b = new byte[1024];
    int k = 0;
    while((k = in.read(b)) > 0)
        out.write(b,0,k);
}

// in and out will be cleaned up after this.

Multiple Catch

You can now catch more than one exception at a time:

try{

    // do stuff here

}catch(IOException | NullPointerException ex)
{
    // Handle either exception
}

New Diamond Operator

No longer do you have to declare the same type in the constructor and variable when you're providing types:

HashMap<String, Integer> myMap = new HashMap<>();

NIO

This is a huge topic, too long to be covered here; but there is a new library for working with various filesystems that abstracts away their differences, so you can use the same code to work remotely, locally, within zip files, etc.

Compute/Fork Join

Java now provides an interface for embarrassingly parallel fork-join tasks (such as sorting), just implement Compute.

Swing Improvements

• Draw on top of components, then erase the drawing, using JLayer
• Make translucent windows with .setOpacity(<float>) on a JFrame
• New HSV tab on JColorChooser.