Java Utililty Methods Assert

void assertArgNotEmptyString(String value, String argName)
assert Arg Not Empty String

if (value.isEmpty()) {
 throw new IllegalArgumentException(String.format("Argument [%s] cannot be an empty String", argName));

void assertArgumentNotMinusInteger(String name, int value)
assert Argument Not Minus Integer

if (value < 0) {
 String msg = "The argument '" + name + "' should be plus or zero value: " + value;
 throw new IllegalArgumentException(msg);

void assertArrayIndex(int arrayLength, int offset, int length)
assert Array Index

if (offset < 0 || length < 0) {
 throw new IndexOutOfBoundsException("Negative index specified");
if ((long) offset + (long) length > arrayLength) {
 throw new IndexOutOfBoundsException("Size mismatch");

void assertArrayIndexScale(final String name, int actualIndexScale, int expectedIndexScale)
assert Array Index Scale

if (actualIndexScale != expectedIndexScale) {
 throw new IllegalStateException(
 name + " array index scale must be " + expectedIndexScale + ", but is " + actualIndexScale);

void assertArrayType(Object array)
Assert the object is array or not

Class<?> type = array.getClass();
if (!type.isArray()) {
 String message = String.format("The argument is not an array object, its type is %s", type.getName());
 throw new IllegalArgumentException(message);

void assertAssertionsEnabled()
assert Assertions Enabled

boolean assertOn = false;
assert assertOn = true;
if (!assertOn) {
 throw new RuntimeException("Asserts not enabled; enable assertions using the '-ea' JVM option");

void assertAttributeNameIsLegal(final String attributeName)
Check whether the given String represents a legal attribute name according to the SAM spec, and throw an exception if it doesn't.

if (attributeName == null || attributeName.length() != 2 || !Character.isLetter(attributeName.charAt(0))
 || !Character.isLetterOrDigit(attributeName.charAt(1))) {
 throw new IllegalArgumentException("Read attribute " + attributeName
 + " invalid: attribute names must be non-null two-character Strings matching the pattern /[A-Za-z][A-Za-z0-9]/");

void assertBounds(final long reqOff, final long reqLen, final long allocSize)
Perform bounds checking using java assert (if enabled) checking the requested offset and length against the allocated size.

assert ((reqOff | reqLen | (reqOff + reqLen) | (allocSize - (reqOff + reqLen))) >= 0) : "offset: " + reqOff
 + ", reqLength: " + reqLen + ", size: " + allocSize;

void assertByThrowing(boolean condition, String errorMessage)
assert By Throwing

if (!condition) {
 throw new RuntimeException(errorMessage);

String assertCharactersNotInString(final String illegalChars, final char... chars)
Checks that a String doesn't contain one or more characters of interest.

for (final char illegalChar : illegalChars.toCharArray()) {
 for (final char ch : chars) {
 if (illegalChar == ch) {
 throw new IllegalArgumentException(
 "Supplied String contains illegal character '" + illegalChar + "'.");
return illegalChars;