9、介紹JAVA中的Collection FrameWork(包括如何寫自己的數(shù)據(jù)結(jié)構(gòu))?
答:Collection FrameWork如下: Collection ├List │├LinkedList │├ArrayList │└Vector │ └Stack └Set Map ├Hashtable ├HashMap └WeakHashMap Collection是最基本的集合接口,一個Collection代表一組Object,即Collection的元素(Elements) Map提供key到value的映射 10、Java中異常處理機(jī)制,事件機(jī)制? 11、JAVA中的多形與繼承?
12、抽象類與接口?
答:抽象類與接口都用于抽象,但是抽象類(JAVA中)可以有自己的部分實現(xiàn),而接口則完全是一個標(biāo)識(同時有多重繼承的功能)。 13、Java 的通信編程,編程題(或問答),用JAVA SOCKET編程,讀服務(wù)器幾個字符,再寫入本地顯示?
答:Server端程序: package test; import java.net.*; import java.io.*; public class Server { private ServerSocket ss; private Socket socket; private BufferedReader in; private PrintWriter out; public Server() { try { ss=new ServerSocket(10000); while(true) { socket = ss.accept(); String RemoteIP = socket.getInetAddress().getHostAddress(); String RemotePort = ":"+socket.getLocalPort(); System.out.println("A client come in!IP:"+RemoteIP+RemotePort); in = new BufferedReader(new InputStreamReader(socket.getInputStream())); String line = in.readLine(); System.out.println("Cleint send is :" + line); out = new PrintWriter(socket.getOutputStream(),true); out.println("Your Message Received!"); out.close(); in.close(); socket.close(); } } catch (IOException e) { out.println("wrong"); } } public static void main(String[] args) { new Server(); } }; Client端程序: package test; import java.io.*; import java.net.*; public class Client { Socket socket; BufferedReader in; PrintWriter out; public Client() { try { System.out.println("Try to Connect to 127.0.0.1:10000"); socket = new Socket("127.0.0.1",10000); System.out.println("The Server Connected!"); System.out.println("Please enter some Character:"); BufferedReader line = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(socket.getOutputStream(),true); out.println(line.readLine()); in = new BufferedReader(new InputStreamReader(socket.getInputStream())); System.out.println(in.readLine()); out.close(); in.close(); socket.close(); } catch(IOException e) { out.println("Wrong"); } } public static void main(String[] args) { new Client(); } }; 14、用JAVA實現(xiàn)一種排序,JAVA類實現(xiàn)序列化的方法(二種)? 如在COLLECTION框架中,實現(xiàn)比較要實現(xiàn)什么樣的接口?
答:用插入法進(jìn)行排序代碼如下 package test; import java.util.*; class InsertSort { ArrayList al; public InsertSort(int num,int mod) { al = new ArrayList(num); Random rand = new Random(); System.out.println("The ArrayList Sort Before:"); for (int i=0;i) { al.add(new Integer(Math.abs(rand.nextInt()) % mod + 1)); System.out.println("al["+i+"]="+al.get(i)); } } public void SortIt() { nteger tempInt; int MaxSize=1; for(int i=1;i ) { tempInt = (Integer)al.remove(i); if(tempInt.intValue()>=((Integer)al.get(MaxSize-1)).intValue()) { al.add(MaxSize,tempInt); MaxSize++; System.out.println(al.toString()); } else { for (int j=0;j) { if (((Integer)al.get(j)).intValue()>=tempInt.intValue()) { al.add(j,tempInt); MaxSize++; System.out.println(al.toString()); break; } } } } System.out.println("The ArrayList Sort After:"); for(int i=0;i) { System.out.println("al["+i+"]="+al.get(i)); } } public static void main(String[] args) { InsertSort is = new InsertSort(10,100); is.SortIt(); } }
JAVA類實現(xiàn)序例化的方法是實現(xiàn)java.io.Serializable接口 Collection框架中實現(xiàn)比較要實現(xiàn)Comparable 接口和 Comparator 接口 |