栈的基本特性是后进先出，最简单的用途是用于转置，还有其他诸如括号匹配，中序表达式(A+B*(C-D/(E+F)) --> ABCDEF+/-*+)和后续表达式(345+*612+/- --> 3*(4+5)-6/(1+2))互换等高级用法。
示例代码：
package chap04.Reverse;
import java.io.*; // for I/O
class StackX {
private int maxSize;
private char[] stackArray;
private int top;
public StackX(int max) {
maxSize = max;
stackArray = new char[maxSize];
top = -1;
}
public void push(char j) {
stackArray[++top] = j;
}
public char pop() {
return stackArray[top--];
}
public char peek() {
return stackArray[top];
}
public boolean isEmpty() {
return (top == -1);
}
public boolean isFull() {
return (top == maxSize - 1);
}
}
class Reverser {
private String input;
private String output;
public Reverser(String in) {
input = in;
}
// 转置
public String doRev() {
int stackSize = input.length();
StackX theStack = new StackX(stackSize);
for (int j = 0; j < input.length(); j++) {
char ch = input.charAt(j);
theStack.push(ch);
}
output = "";
while (!theStack.isEmpty()) {
char ch = theStack.pop();
output = output + ch;
}
return output;
}
}
class ReverseApp {
public static void main(String[] args) throws IOException {
String input, output;
while (true) {
System.out.print("Enter a string: ");
System.out.flush();
input = getString1();
if (input.equals("")) {
break;
}
Reverser theReverser = new Reverser(input);
output = theReverser.doRev();
System.out.println("Reversed: " + output);
}
}
public static String getString1() throws IOException {
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
String s = br.readLine();
return s;
}
}