Java實驗之泛型與集合框架

搭建流水線

實驗要求

程式有時候需要將任務按流水式進行，例如評判體操選手的任務按流水式為依次的三個步驟：錄入裁判給選手的分數，去掉一個最高分和最低分，計算出平均成績，撰寫程式，搭建流水線，只需將評判體操選手的任務交給流水線即可，

運行效果

代碼

// DoThing.java
public abstract class DoThing {
    public abstract void doThing(double [] a);
    public abstract void setNext(DoThing next);
}

// DelMaxAndMin.java
import java.util.*;
public class DelMaxAndMin extends DoThing {
    DoThing nextDoThing;
    public void setNext(DoThing next){
        nextDoThing=next;
    }
    public void doThing(double []a){
        Arrays.sort(a);
        double []b=Arrays.copyOfRange(a,1,a.length);
        System.out.print("去掉一個最高分"+b[b.length-1]+",");
        System.out.print("去掉一個最低分"+b[0]);
        nextDoThing.doThing(b);
    }
}   

// ComputerAver.java
public class ComputerAver extends DoThing {
    DoThing nextDoThing;
    public void setNext(DoThing next){
        nextDoThing=next;
    }
    public void doThing(double[]a){
        double sum=0;
        for(int i=0;i<a.length;i++){
            sum=sum+a[i];
        }
        double aver=sum/a.length;
        System.out.print("選手最后得分"+aver);
    }
}

// Main.java
public class Main {

    public static void main(String[] args) {
        StreamLine line=new StreamLine();
        double []a=new double[1];
        line.giveResult(a);
    }
}

排序與查找

實驗要求

撰寫一個Book類，該類至少有price成員變數，該類要實作Comparable介面，在介面的compareTo()方法中規定Book類兩個實體的大小關系為二者的price成員的大小關系，
撰寫一個主類SortSearchMainClass，在main()方法中將Book類的若干個物件存放到一個鏈表中，然后再用Book類創建一個新的物件，并檢查這個物件和鏈表中哪些物件相等，

運行結果

代碼

// Book.java
public class Book implements Comparable{
    double price;
    String name;
    public void setPrice(double c){
        price=c;
    }
    public double getPrice(){
        return price;
    }
    public void setName(String n){
        name=n;
    }
    public String getName(){
        return name;
    }
    public int compareTo(Object object){
        Book bk=(Book) object;
        int difference=(int) ((this.getPrice()- bk.getPrice())*10000);
        return difference;
    }
}

// Main.java
import java.util.*;
public class Main {

    public static void main(String[] args) {
        List<Book>bookList=new LinkedList<Book>();
        String bookName[]={"Java 基礎教程","XML基礎教程","JSP基礎教程","C++基礎教程",
        "J2ME編程","作業系統","資料庫技術"};
        double bookPrice[]={29,21,22,29,34,32,29};
        Book book[]=new Book[bookName.length];
        for(int k=0;k<book.length;k++){
            book[k]=new Book();
            book[k].setName(bookName[k]);
            book[k].setPrice(bookPrice[k]);
            bookList.add(book[k]);
        }
        Book newBook=new Book();
        newBook.setPrice(29);
        newBook.setName("Java與模式");
        Collections.sort(bookList);
        int m=-1;
        System.out.println("新書："+newBook.getName()+"("+newBook.getPrice()+")與下列圖書：");
        while ((m=Collections.binarySearch(bookList,newBook,null))>=0){
            Book bk=bookList.get(m);
            System.out.println("\t"+bk.getName()+"("+bk.getPrice()+")");
            bookList.remove(m);
        }
        System.out.println("價錢相同，");
    }
}

使用TreeSet排序

實驗要求

撰寫一個應用程式，用戶分別從兩個文本框輸入學生的姓名和分數，程式按成績排序將這些學生的姓名和分數顯示在一個文本區內，

運行效果

代碼

// Student.java
public class Student implements Comparable{
    String name;
    int score;
    Student(String name,int score){
        this.name=name;
        this.score=score;
    }
    public int compareTo(Object b){
        Student st=(Student) b;
        int m=this.score-st.score;
        if(m!=0){
            return m;
        }
        else {
            return 1;
        }
    }
    public int getScore(){
        return score;
    }
    public String getName(){
        return name;
    }
}

// StudentFrame.java
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.text.Style;

public class StudentFrame extends JFrame implements ActionListener{
    JTextArea showArea;
    JTextField inputName,inputScore;
    JButton button;
    TreeSet<Student> treeSet;
    StudentFrame(){
        treeSet=new TreeSet<Student>();
        showArea=new JTextArea();
        showArea.setFont(new Font("",Font.BOLD,20));
        inputName=new JTextField(5);
        inputScore=new JTextField(5);
        button=new JButton("確定");
        button.addActionListener((ActionListener) this);
        JPanel pNorth=new JPanel();
        pNorth.add(new JLabel("Name:"));
        pNorth.add(inputName);
        pNorth.add(new JLabel("Score:"));
        pNorth.add(inputScore);
        pNorth.add(button);
        add(pNorth,BorderLayout.NORTH);
        add(showArea,BorderLayout.CENTER);
        setSize(300,320);
        setVisible(true);
        validate();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    public void actionPerformed(ActionEvent e){
        String name=inputName.getText();
        int score=0;
        try{
            score=Integer.parseInt(inputScore.getText().trim());
            if(name.length()>0){
                Student stu=new Student(name,score);
                treeSet.add(stu);
                show(treeSet);
            }
        }
        catch (NumberFormatException exp){
            inputScore.setText("請輸入數字字符");
        }
    }
    public void show(TreeSet tree){
        showArea.setText(null);
        Iterator<Student> te=treeSet.iterator();
        while (te.hasNext()){
            Student stu=te.next();
            showArea.append("Name:"+stu.getName()+"Score:"+stu.getScore()+"\n");
        }
    }
    public static void main(String[] args) {
        new StudentFrame();
    }
}

掃雷小游戲

實驗要求

撰寫一個Block類，Block物件具有String型別和boolean型別的成員變數，Block物件可以使用setName（String）方法、getName（）方法、isName（）方法、setIsMine（）方法來設定物件的名字、回傳該物件的名字、回傳物件的boolean型別成員的值、設定物件的boolean型別成員的值，
撰寫一個LayMines類，該類提供一個public void layMinesForBlock(Block block[][],int mineCount)方法，該方法可以隨機地將引數block指定的二維陣列中的mineCount個單元設定為“雷”，
撰寫一個BlockView類，該類的實體為Block物件提供視圖，
撰寫MineFrame表單類，該類將Block類的實體和BlockView類的實體作為成員，并負責二者之間的互動，

運行結果

代碼

// Block.java
public class Block {
    String name;
    int number;
    boolean boo=false;
    public void setName(String name){
        this.name=name;
    }
    public void setNumber(int n){
        number=n;
    }
    public int getNumber(){
        return number;
    }
    public String getName(){
        return name;
    }
    boolean isMine(){
        return boo;
    }
    public void setIsMine(boolean boo){
        this.boo=boo;
    }
}

// LayMine.java
import java.util.*;
public class LayMine {
    public void layMinesForBlock(Block block[][],int mineCount){
        int row= block.length;;
        int column=block[0].length;
        LinkedList<Block>list=new LinkedList<Block>();
        for(int i=0;i<row;i++){
            for(int j=0;j<column;j++){
                list.add(block[i][j]);
            }
        }
        while (mineCount>0){
            int size=list.size();
            int randomIndex=(int) (Math.random()*size);
            Block b=list.get(randomIndex);
            b.setName("雷");
            b.setIsMine(true);
            list.remove(randomIndex);
            mineCount--;
        }
        for(int i=0;i<row;i++){
            for(int j=0;j<column;j++) {
                if (block[i][j].isMine()) {
                }
                else {
                    int mineNumber = 0;
                    for (int k = Math.max(i - 1, 0); k <= Math.min(i + 1, row - 1); k++) {
                        for (int t = Math.max(j - 1, 0); t <= Math.min(j + 1, column - 1); t++) {
                            if (block[k][t].isMine())
                                mineNumber++;
                        }
                    }
                    if (mineNumber > 0) {
                        block[i][j].setName("" + mineNumber);
                        block[i][j].setNumber(mineNumber);
                    } else {
                        block[i][j].setName(" ");
                        block[i][j].setNumber(mineNumber);
                    }

                }
            }
        }
    }
}

// BlockView.java
import java.awt.*;
import javax.swing.*;
public class BlockView extends JPanel{
    JLabel blockName;
    JButton blockCover;
    CardLayout card;
    BlockView(){
        card=new CardLayout();
        setLayout(card);
        blockName=new JLabel();
        blockCover=new JButton();
        add("Cover",blockCover);
        add("name",blockName);
    }
    public void setName(String name){
        blockName.setText(name);
    }
    public String getName(){
        return blockName.getText();
    }
    public void seeBlockName(){
        card.show(this,"name");
        validate();
    }
    public void seeBlockCover(){
        card.show(this,"cover");
        validate();
    }
    public JButton getBlockCover(){
        return blockCover;
    }
}

// MineMainFrame.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MineMainFrame extends JFrame implements ActionListener{
    JButton reStart;
    Block block[][];
    BlockView blockView[][];
    LayMine lay;
    int row=10,colum=12,mineeCount=22;
    int colorSwitch=0;
    JPanel pCenter,pNorth;
    public MineMainFrame(){
        reStart=new JButton("重新開始");
        pCenter=new JPanel();
        pNorth=new JPanel();
        pNorth.setBackground(Color.CYAN);
        block=new Block[row][colum];
        for(int i=0;i<row;i++){
            for(int j=0;j<colum;j++)
                block[i][j]=new Block();
        }
        lay=new LayMine();
        lay.layMinesForBlock(block,mineeCount);
        blockView=new BlockView[row][colum];
        pCenter.setLayout(new GridLayout(row,colum));
        for (int i=0;i<row;i++){
            for(int j=0;j<colum;j++){
                blockView[i][j]=new BlockView();
                blockView[i][j].setName(block[i][j].getName());
                pCenter.add(blockView[i][j]);
                blockView[i][j].getBlockCover().addActionListener(this);
            }
        }
        reStart.addActionListener(this);
        pNorth.add(reStart);
        add(pNorth,BorderLayout.NORTH);
        add(pCenter,BorderLayout.CENTER);
        setSize(200,232);
        setVisible(true);
        validate();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    public void actionPerformed(ActionEvent e){
        JButton source=(JButton)e.getSource();
        if(source!=reStart){
            int m=-1,n=-1;
            for(int i=0;i<row;i++){
                for(int j=0;j<colum;j++){
                    if(source==blockView[i][j].getBlockCover()){
                        m=i;
                        n=j;
                        break;
                    }
                }
            }
            if(block[m][n].isMine()){
                for(int i=0;i<row;i++){
                    for (int j=0;j<colum;j++){
                        blockView[i][j].getBlockCover().removeActionListener(this);
                        if(block[i][j].isMine())
                            blockView[i][j].seeBlockName();
                    }
                }
            }
            else{
                if(block[m][n].getNumber()>0)
                    blockView[m][n].seeBlockName();
                else if(block[m][n].getNumber()==0)
                    for(int k =Math.max(m-1,0);k<=Math.min(m+1,row-1);k++){
                        for(int t = Math.max(n-1,0); t<=Math.min(n+1,colum-1); t++) {
                            blockView[k][t].seeBlockName();
                        }
                }
            }
        }
        if(source==reStart){
            for(int i=0;i<row;i++){
                for(int j=0;j<colum;j++)
                    block[i][j].setIsMine(false);
            }
            lay.layMinesForBlock(block,mineeCount);
            for(int i=0;i<row;i++){
                for(int j=0;j<colum;j++){
                    blockView[i][j].setName(block[i][j].getName());
                    blockView[i][j].seeBlockCover();
                    blockView[i][j].getBlockCover().addActionListener(this);
                }
            }
        }
    }
    public static void main(String args[]){
        new MineMainFrame();
    }
}