filerecord.java

继承和多态 实验目的： 1、 掌握继承和多态的概念与实现方法 2、 掌握如何从已有的类中派生子类并继承父类 3、 掌握方法的覆盖和重载 实验内容： 设计一个通用的排序算法

package generalSort;

import java.io.PrintWriter;
import java.io.FileWriter;
import java.io.File;
import java.io.IOException;

/**
 * <p>Title: FileRecord</p>
 *
 * <p>Description:A class for operating the file, which has two methods
 ****Method void append_tofile(String content) appends 'content' to the end of the file "C:\\GeneralSort_Report.doc"
 ****Method boolean openfile() opens the file "C:\\GeneralSort_Report.doc"
 *  </p>
 * <p>Copyright: Copyright (c) 2008 All rights reserved</p>
 * <p>Organization :Shandong University </p>
 * @Email:[e-mail]
 * @author: Xiao Ruohan
 * @version 1.0
 */
public class FileRecord {
    private static String file_name = "C:\\GeneralSort_Report.doc";
    private String changedString = "";
    private File f = new File(file_name);
    private FileWriter fw = null;
    private PrintWriter pw = null;
    private String analysis_content =
            "<-----------------------GeneralSort Report--------------------------->";

    public FileRecord() {
        this.append_tofile(this.analysis_content);
    }

    public FileRecord(String fname) {
        file_name = fname;
    }

    public void append_tofile(String content) {
        try {
            if (!f.exists()) { //检查文件是否存在
                f.createNewFile(); //删除文件
            }

            fw = new FileWriter(f, true); //建立FileWriter对象，并实例化fw
            //将字符串写入文件
            pw = new PrintWriter(fw);
            changedString = content.replaceAll("\n",
                                               System.getProperty(
                    "line.separator")); //将换行符转换为系统默认的换行符
            pw.println(changedString);
            pw.close();
            fw.close();

        } catch (IOException ex) {
        }

    }

    public boolean open_file() {
        try {
            Runtime.getRuntime().exec(
                    "cmd.exe /c start " + file_name); //打开文件记录
            return true;
        } catch (Exception ex) {
            ex.printStackTrace();
            System.out.println("Fail to open the file" + file_name);
            return false;
        }
    }

}