Develop a data storage container using internal classes to store data containers

Develop a data storage container using internal classes to store data containers

Case study: a container is developed to store key-value pairs, English names, Chinese names, and internal classes;

Case Design:

① Use static internal classes to encapsulate key-value pairs;

② By default, the container size is 5, which is twice the size of the container if the container size exceeds 5;

③ Call the entryArrays method to return data in the container;

1 import java. util. arrays; 2 public class EntryDemo {3 public static void main (String [] args) {4 MyContainer container = new MyContainer (); 5 container. put ("jack", "jack"); 6 container. put ("jay", "jay Chou"); 7 container. put ("john", "john"); 8 container. put ("rose", "rose"); 9 container. put ("jack", "James"); 10 11 MyContainer. entry [] entrys = container. entryArrays (); 12 for (int I = 0; I <entrys. length; I ++) {13 MyContainer. entry entry = entrys [I]; 14 System. out. println (entry. getKey () + "--" + entry. getValue (); 15} 16} 17} 18 19 class MyContainer {20 // array for storing entry objects, default size: 521 private Entry [] entrys = new Entry [5]; 22 private int count = 0; 23 24 // provide an external interface to store encapsulated data in the container 25 public void put (String key, String value) {26 Entry entry = new Entry (); 27 entry. setKey (key); 28 entry. setValue (value); 29 entrys [count ++] = entry; // store the entry object to the array 30 // resize the Array 31 if (count> = entrys. length) {32 // the size of the new expanded array 33 int newCapacity = entrys. length * 2; 34 // copy the data in the old array to 35 entrys = Arrays in the new array with the length newCapacity. copyOf (entrys, newCapacity); 36} 37} 38 39 // return 40 public Entry [] entryArrays () {41 return Arrays. copyOfRange (entrys, 0, count); 42} 43 44 // encapsulate key-value pairs in the Entry object 45 public static class Entry {46 private String key; 47 private String value; 48 public void setKey (String key) {49 this. key = key; 50} 51 public String getKey () {52 return key; 53} 54 public void setValue (String value) {55 this. value = value; 56} 57 public String getValue () {58 return value; 59} 60} 61}