Java 1.5 小手册 Cheat Sheet

Create a new object instance

StringBuffer buffer = new StringBuffer(128);

Output a string to standard output

System.out.println("Some string");

Create a new object using generic types (array list that holds strings)

ArrayList<String> list = new ArrayList<String>();

For Each Loop (loop over any Iterable object, or array this way)

String[] spaghetti = { "a", "b", "c"};
for (String noodle : spaghetti) {
  System.out.println(noodle);
}

JavaDocs Example

/**
 * HTML Description here
 * @author Bob
 * @version 1.0
 * @see java.lang.String
 */
public class Foo {
	/**
	 * Method description
	 * @param arg1 The first arg
	 * @param arg2 The second arg
	 * @throws FooException if things are bad
	 * @return what it returns
	 */
	public String bar(int arg1, int arg2) throws FooException { }
}

Enum Example

public enum Day { SUN, MON, TUE, WED, THU, FRI, SAT }

public void checkDay(Day d) {
	if (d == Day.FRI) {
		System.out.println("Yippie!");
	}
}

Annotations Example

/** Use to define a license for an annotated element */
public @interface License {
	String value();
}

@License("GPL")
public class MyGPLLicensedClass { ... }

Main - Hello World

public class TestRun {
	public static final void main(String[] args) {
		System.out.println("Hello World.");
	}
}

From: http://www.petefreitag.com/cheatsheets/java/