Java implementation stack (can be put in infinity)

Always want to use Java to implement the stack, queue, but no time, immediately to find an internship, on the review of the algorithm, to achieve a simple stack, the code is still problematic, interested brothers help correct

　　Problem: Multi-threaded words pop and push can only have one method to be executed need to add mutex variable

　　　　　

Importjava.util.Arrays; Public classStack<item> {    Private transientobject[] data;//Storing Data    Private intTop//represents the top element of the stack    Private intoldcapacity;  PublicStack () {oldcapacity= 100; Data=NewObject[oldcapacity];//need to expand to re-build the array, copy this to the pasttop =-1; }     Public synchronized voidPut (Item t) {//Press Stack        if(Top >oldcapacity-2) {            intNewcapacity = (oldcapacity * 3)/2 + 1;//imitate ArrayList to increase the length of array lengthOldcapacity =newcapacity; Data=arrays.copyof (data, newcapacity); } Top++; Data[top]=T; }     Public synchronizedItem Pop () {//out of the stack        if(Top < 0) {            return NULL; } Item T=(Item) data[top]; Top--; returnT; }}

Java implementation stack (can be put in infinity)