public class CallNameDemo {
    public static void main(String[] args) throws IOException {
        //創(chuàng)建字符緩沖輸入流對象 
        BufferedReader br = new BufferedReader(new FileReader("myCharStream\\names.txt"));
 
        //創(chuàng)建ArrayList集合對象 
        ArrayList<String> array = new ArrayList<String>();
 
        //調用字符緩沖輸入流對象的方法讀數(shù)據(jù) 
        String line;
        while ((line=br.readLine())!=null) {
            //把讀取到的字符串數(shù)據(jù)存儲到集合中 
            array.add(line);
        }
 
        //釋放資源 
        br.close();
 
        //使用Random產(chǎn)生一個隨機數(shù)，隨機數(shù)的范圍在：[0,集合的長度) 
        Random r = new Random();
        int index = r.nextInt(array.size());
 
        //把第6步產(chǎn)生的隨機數(shù)作為索引到ArrayList集合中獲取值 
        String name = array.get(index);
 
        //把第7步得到的數(shù)據(jù)輸出在控制臺 
        System.out.println("幸運者是：" + name);
    }
}

public class Student {
    private String sid;
    private String name;
    private int age;
    private String address;
 
    public Student() {
    }
 
    public Student(String sid, String name, int age, String address) {
        this.sid = sid;
        this.name = name;
        this.age = age;
        this.address = address;
    }
 
    public String getSid() {
        return sid;
    }
 
    public void setSid(String sid) {
        this.sid = sid;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public int getAge() {
        return age;
    }
 
    public void setAge(int age) {
        this.age = age;
    }
 
    public String getAddress() {
        return address;
    }
 
    public void setAddress(String address) {
        this.address = address;
    }
}

public class ArrayListToFileDemo {
    public static void main(String[] args) throws IOException {
        //創(chuàng)建ArrayList集合 
        ArrayList<Student> array = new ArrayList<Student>();
 
        //創(chuàng)建學生對象 
        Student s1 = new Student("itheima001", "小林", 20, "西安");
        Student s2 = new Student("itheima002", "小張", 25, "武漢");
        Student s3 = new Student("itheima003", "小王", 23, "鄭州");
 
        //把學生對象添加到集合中 
        array.add(s1);
        array.add(s2);
        array.add(s3);
 
        //創(chuàng)建字符緩沖輸出流對象 
        BufferedWriter bw = new BufferedWriter(new FileWriter("myCharStream\\students.txt"));
 
        //遍歷集合，得到每一個學生對象 
        for (Student s : array) {
            //把學生對象的數(shù)據(jù)拼接成指定格式的字符串 
            StringBuilder sb = new StringBuilder();
            sb.append(s.getSid()).append(",").append(s.getName()).append(",").append(s.ge tAge()).append(",").append(s.getAddress());
 
            //調用字符緩沖輸出流對象的方法寫數(shù)據(jù) 
            bw.write(sb.toString());
            bw.newLine();
            bw.flush();
        }
 
        //釋放資源 
        bw.close();
    }
}

public class FileToArrayListDemo {
    public static void main(String[] args) throws IOException {
        //創(chuàng)建字符緩沖輸入流對象 
        BufferedReader br = new BufferedReader(new FileReader("myCharStream\\students.txt"));
 
        //創(chuàng)建ArrayList集合對象 
        ArrayList<Student> array = new ArrayList<Student>();
 
        //調用字符緩沖輸入流對象的方法讀數(shù)據(jù) 
        String line;
        while ((line = br.readLine()) != null) {
            //把讀取到的字符串數(shù)據(jù)用split()進行分割，得到一個字符串數(shù)組 
            String[] strArray = line.split(",");
 
            //創(chuàng)建學生對象 
            Student s = new Student();
            //把字符串數(shù)組中的每一個元素取出來對應的賦值給學生對象的成員變量值 
            //itheima001,林青霞,30,西安 
            s.setSid(strArray[0]);
            s.setName(strArray[1]);
            s.setAge(Integer.parseInt(strArray[2]));
            s.setAddress(strArray[3]);
 
            //把學生對象添加到集合 
            array.add(s);
        }
 
        //釋放資源 
        br.close();
 
        //遍歷集合 
        for (Student s : array) {
            System.out.println(s.getSid() + "," + s.getName() + "," +
                    s.getAge() + "," + s.getAddress());
        }
    }
}