studentfromcfg.java

java编写的桌面考试系统.含所有源码.

package exam.dao;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import exam.model.Student;


public class StudentFromCfg implements StudentDao {

	private Student[] data;
	private int count;
	private File studentCfg = new File("student.cfg");

	public StudentFromCfg() {
		data = new Student[1];
		count = 0;
		init(studentCfg);
	}

	public void init(File studentCfg) {
		FileInputStream fis = null;
		InputStreamReader isr = null;
		BufferedReader br = null;

		try {
			fis = new FileInputStream(studentCfg);
			isr = new InputStreamReader(fis);
			br = new BufferedReader(isr);
			String str = null;
			while ((str = br.readLine()) != null) {
				String[] s = str.split(":");
				if (data.length == count)
					extendData();
				data[count++] = new Student(Integer.parseInt(s[0]), s[1], s[2]);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (br != null) {
				try {
					br.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (isr != null) {
				try {
					isr.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (fis != null) {
				try {
					fis.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

	public void extendData() {
		Student[] temp = new Student[data.length + 1];
		System.arraycopy(data, 0, temp, 0, data.length);
		data = temp;
		System.gc();
	}

	public Student getStudent(int id, String password) {
		for (int i = 0; i < count; i++) {
			if (data[i].getId() == id && data[i].getPassword().equals(password)) {
				return data[i];
			}
		}
		return null;
	}
}