事例共有: Java を使用した会計システムの開発と実装 (完全なコード)

package com.ss.file;
import java.io.*;
public class FileIO {

	private String filename = "tally.txt";
	public FileIO() {
		File file = new File(filename);
		if(!file.exists()) {
			try {
				file.createNewFile();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	public void write(String data,boolean mode) {
		try {
			FileWriter fw = new FileWriter(filename,mode);
			BufferedWriter bw = new BufferedWriter(fw);
			bw.write(data);
			bw.close();
			fw.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public String read() {
		FileReader fr;
		String line = "";
		String fileStr = "";
		try {
			fr = new FileReader(filename);//不能一行行的读
			BufferedReader br = new BufferedReader(fr);//可以一行行的读效率高
			while((line = br.readLine()) != null) {
				fileStr += line + "\n";
			}
			br.close();
			fr.close();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return fileStr;
	}
	public String getFilename() {
		return filename;
	}
	public void setFilename(String filename) {
		this.filename = filename;
	}

}

package com.ss.oper;
import java.util.Vector;

import com.ss.file.FileIO;
import com.ss.util.Tool;
public class Operation {
	FileIO io = new FileIO();
	public void add(String data) {
		io.write(data, true);
	}
	public void delete(String data) {
		io.write(data, false);
	}
	public void update(String data) {
		io.write(data, false);
	}
	/*
	 * 全部查询
	 */
	public Vector select() {
		String str = io.read();
		Tool tool = new Tool();
		return tool.StringToVec(str);
	}
	/*
	 * 条件查询
	 */
	public Vector select(String type,String remark) {
		Vector vecData = new Vector();
		Vector vecAll = select();
		for(int i = 0;i < vecAll.size();i++) {
			Vector smallVec = (Vector)vecAll.get(i);
			boolean select = (smallVec.get(1).toString().equals(type) || type.equals(""))
					&&
					(smallVec.get(4).toString().equals(remark) || remark.equals(""));
			if(select) {
				vecData.add(smallVec);
			}
		}
		return vecData;
	}

}