Some basic unit tests for URLEncoder.java.

URLEncoderTest.java

import org.junit.Assert;
import org.junit.Test;

public class URLEncoderTest extends Assert {

	public static void assertCharSequenceEquals( CharSequence expected, CharSequence actual ) {
		for( int i = 0; i < expected.length(); i++ ) {
			assertEquals( "at position " + i, expected.charAt( i ), actual.charAt( i ) );
		}
	}

	public static void assertEncodeResults( CharSequence expected, CharSequence input ) {
		CharSequence actual = URLEncoder.encode( input );
		assertCharSequenceEquals( expected, actual );
	}

	@Test
	public void encode_shouldEncodeOtherSpecialCharactersAsPercentPrefixedBase16() {
		assertEncodeResults( "!%40%23%24%25%5E%26*()-%3D_%2B%5B%5D%5C%7B%7D%7C%3B'%3A%22%2C.%2F%3C%3E%3F%60~", "!@#$%^&*()-=_+[]\\{}|;':\",./<>?`~" );
	}

	@Test
	public void encode_shouldNotEncodeAlphanumerics() {
		CharSequence input = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
		assertEncodeResults( input, input );
	}

	@Test
	public void encode_shouldNotEncodeCertainSpecialCharacters() {
		CharSequence input = "!*()-_'.~";
		assertEncodeResults( input, input );
	}

}