我创建了两个文件，一个文件的界面如下：
public interface ICharQ {
void put(char ch);
char get();
}
和实现类如下：
//A fixed size Queue class for characters
class FixedQueue implements ICharQ{
private char q[]; //This queue holds the characters
private int putloc, getloc; //the put and get indices
public FixedQueue(int size){
q = new char[size+1]; //allocate memory for the queue
putloc = getloc = 0;
}
//Put a character into the queue
public void put(char ch){
if(putloc == q.length - 1){
System.out.println(" - Queue is full");
return;
}
putloc++;
q[putloc] = ch;
}
//Get a character from the Queue
public char get(){
if(getloc == putloc){
System.out.println(" - Queue is empty");
return (char) 0;
}
getloc++;
return q[getloc];
}
}
//A circular Queue
class CircularQueue implements ICharQ{
private char q[]; //This queue holds the characters
private int putloc, getloc; //the put and get indices
public CircularQueue(int size){
q = new char[size+1]; //allocate memory for the queue
putloc = getloc = 0;
}
//Put a character into the queue
public void put(char ch){
/*Queue is full if putloc is one less than getloc or if putloc is at the end and getloc is at the beginning */
if((putloc + 1 == getloc)|(putloc == q.length-1 & getloc == 0)){
System.out.println(" - Queue is full");
return;
}
putloc++;
if(putloc == q.length) putloc = 0; //reset loop
q[putloc] = ch;
}
//Get character from the Queue
public char get(){
if(getloc == putloc){
System.out.println(" - Queue is empty");
return (char) 0;
}
getloc++;
if(getloc == q.length) getloc = 0;
return q[getloc];
}
}
//A dynamic Queue
class DynQueue implements ICharQ {
private char q[]; // this array holds the queue
private int putloc, getloc; // the put and get indices
// Construct an empty queue given its size.
public DynQueue(int size) {
q = new char[size+1]; // allocate memory for queue
putloc = getloc = 0;
}
//put a character into the queue
public void put(char ch){
if(putloc == q.length-1){
//increase queue size
char t[] = new char[q.length * 2];
//copy elements into the new queue
for(int i=0; i<q.length; i++)
t[i] = q[i];
q = t;
}
putloc++;
q[putloc] = ch;
}
// Get a character from the queue.
public char get() {
if(getloc == putloc) {
System.out.println(" – Queue is empty.");
return (char) 0;
}
getloc++;
return q[getloc];
}
}
//Demonstrate the ICharQ interface
class IQDemo{
public static void main(String args[]){
FixedQueue q1 = new FixedQueue(10);
DynQueue q2 = new DynQueue(5);
CircularQueue q3 = new CircularQueue(10);
ICharQ iQ;
char ch;
int i;
iQ = q1;
//Put some characters into the fixed queue
for(i = 0; i<10; i++){
iQ.put((char)('A' + i));
}
//Show the queue
for(i=0; i<10; i++){
System.out.print("Contents of fixed queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
System.out.print(ch);
}
}
System.out.println();
iQ = q2;
// Put some characters into dynamic queue.
for(i=0; i < 10; i++)
iQ.put((char) ('Z' - i));
// Show the queue.
System.out.print("Contents of dynamic queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
System.out.print(ch);
}
System.out.println();
iQ = q3;
// Put some characters into circular queue.
for(i=0; i < 10; i++)
iQ.put((char) ('A' + i));
// Show the queue.
System.out.print("Contents of circular queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
System.out.print(ch);
}
System.out.println();
// Put more characters into circular queue.
for(i=10; i < 20; i++)
iQ.put((char) ('A' + i));
// Show the queue.
System.out.print("Contents of circular queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
System.out.print(ch);
}
System.out.println("\nStore and consume from" +
" circular queue.");
// Use and consume from circular queue.
for(i=0; i < 20; i++) {
iQ.put((char) ('A' + i));
ch = iQ.get();
System.out.print(ch);
}
}
}
现在这些文件位于同一目录中。ICharQ.java 文件编译得很好。但是当我试图编译 IQDemo.java 时，它会给出错误，指出它找不到 ICharQ。
但是，当我从接口文件中删除公共访问器并将代码包含在 IQDemo 中时，它可以完美运行。但是，当我将其更改为公开时，它并没有编译。
代码有问题还是我错过了什么？请帮忙。