99/**
1010 * linkedList based implementation of queue.
1111 * This implementation is not thread safe and need exclusive thread safety measures from the client.
12+ *
1213 * @param <T>
1314 */
1415public class GeneralQueue <T >implements Queue <T > {
1516
1617private LinkedList <T >queue ;
1718private Iterator <T >itr ;
1819
19- //Overloaded constructor to create queue of specific size
20+ /**
21+ * Overloaded constructor to create queue of specific size
22+ */
2023public GeneralQueue () {
2124queue =new LinkedList <>();
2225 }
2326
2427@ Override
2528public boolean add (T t ) {
2629
27- if (queue ==null ) {
30+ if queue ==null ) {
2831throw new IllegalStateException ();
2932 }
30- if (t ==null ){
31- throw new NullPointerException ();
33+ if t ==null )
34+ throw new NullPointerException ();
3235 }
3336queue .add (t );
3437return true ;
3538 }
3639
3740@ Override
3841public boolean remove (T t ) {
39- if (null ==queue ){
42+ if null ==queue )
4043throw new NullPointerException ();
4144 }
42- if (queue .isEmpty ()) {
45+ if queue .isEmpty ()) {
4346throw new NoSuchElementException ();
4447 }
4548queue .remove (t );
@@ -48,18 +51,12 @@ public boolean remove(T t) {
4851
4952@ Override
5053public boolean isEmpty () {
51-
52- if (null ==queue ||queue .size () ==0 ){
53- return true ;
54- }
55-
56- return false ;
54+ return null ==queue ||queue .size () ==0 ;
5755 }
5856
5957@ Override
6058public Iterator <T >iterator () {
61-
62- if (queue ==null ) {
59+ if (queue ==null ) {
6360return null ;
6461 }
6562itr =queue .iterator ();
@@ -68,10 +65,10 @@ public Iterator<T> iterator() {
6865
6966@ Override
7067public boolean offer (T t ) {
71- if (null ==queue ) {
68+ if null ==queue ) {
7269return false ;
7370 }
74- if (t ==null ){
71+ if t ==null )
7572throw new NullPointerException ();
7673 }
7774queue .add (t );
@@ -80,18 +77,16 @@ public boolean offer(T t) {
8077
8178@ Override
8279public T poll () {
83-
84- if (queue ==null ||queue .isEmpty ()){
85- return null ;
80+ if (queue ==null ||queue .isEmpty ()) {
81+ return null ;
8682 }
8783
8884return queue .pollFirst ();
8985 }
9086
9187@ Override
9288public T element () {
93-
94- if (queue ==null ||queue .isEmpty ()) {
89+ if (queue ==null ||queue .isEmpty ()) {
9590throw new NoSuchElementException ();
9691 }
9792
@@ -100,37 +95,31 @@ public T element() {
10095
10196@ Override
10297public T peek () {
103- if (null ==queue ||queue .size () ==0 ){
104- return null ;
98+ if null ==queue ||queue .size () ==0 )
99+ return null ;
105100 }
106101
107102return queue .peekFirst ();
108103 }
109104
110105@ Override
111106public boolean hasNext () {
112-
113- if (itr .hasNext ()){
114- return true ;
115- }
116- return false ;
107+ return itr .hasNext ();
117108 }
118109
119110@ Override
120111public T next () {
121-
122112return itr .next ();
123113 }
124114
125115@ Override
126116public Object []toArray () {
127-
128117Object []elements = {};
129- if (null ==queue ||queue .isEmpty ()){
118+ if null ==queue ||queue .isEmpty ())
130119return elements ;
131120 }
132121elements =new Object [queue .size ()];
133- for (int i = 0 ; i < queue .size ();i ++){
122+ for int i = 0 ; i < queue .size ();i ++)
134123elements [i ] =queue .get (i );
135124 }
136125
@@ -139,12 +128,9 @@ public Object[] toArray() {
139128
140129@ Override
141130public int size () {
142- if (null ==queue ||queue .isEmpty ()) {
131+ if null ==queue ||queue .isEmpty ()) {
143132return 0 ;
144133 }
145-
146134return queue .size ();
147135 }
148-
149-
150136}