java基础之(一) Io操作 字节和字符

package io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.Date;

public class FileIo {
	private static SimpleDateFormat sdf = new SimpleDateFormat(
			"yyyy-MM-dd HH:mm:ss S");
	/**
	 * 目标文件路径
	 */
	public static final String SAVE_PATH = "d://student.txt";
	/**
	 * 复制文件路径 字节
	 */
	public static final String COPY_PATH = "d://byte.txt";

	/**
	 * 字节流操作 查询数据库,将数据写入文件。
	 * 
	 * @throws Exception
	 */
	public static void stream(String savePath) throws Exception {
		// 计算运行时间

		long startTime = System.currentTimeMillis();
		System.out.println("字节流操作--读取数据库开始时间:"
				+ sdf.format(new Date(startTime)));

		File file = new File(savePath);
		OutputStream ops = new FileOutputStream(file);
		BufferedOutputStream bos = new BufferedOutputStream(ops);
		String sql = "select * from student";
		Connection conn = DbUtils.getConn();
		Statement state = conn.createStatement();
		ResultSet rs = state.executeQuery(sql);
		// 获取表列名
		ResultSetMetaData metaData = rs.getMetaData();
		for (int i = 1; i <= metaData.getColumnCount(); i++) {
			bos.write(metaData.getColumnLabel(i).getBytes());
			bos.write("\t".getBytes());
		}
		bos.write("\r\n".getBytes());

		// 读取数据
		while (rs.next()) {
			bos.write(rs.getBytes(1));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(2));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(3));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(4));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(5));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(6));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(7));
			bos.write("\t".getBytes());
			bos.write(rs.getBytes(8));
			bos.write("\t".getBytes());
			bos.write("\r\n".getBytes());
		}
		bos.flush();
		ops.close();
		bos.close();
		// 计算结束时间
		long endTime = System.currentTimeMillis();
		System.out.println("字节流操作--读取数据库结束时间:" + sdf.format(new Date(endTime)));
	}

	/**
	 * 字节流操作 复制文件
	 * 
	 * @param savePath
	 * @param copyPath
	 * @throws Exception
	 */
	public static void copy(String savePath, String copyPath) throws Exception {
		long startTime = System.currentTimeMillis();
		System.out.println("字节流操作--复制开始时间:" + sdf.format(new Date(startTime)));
		File file = new File(savePath);
		if (file.exists()) {
			FileInputStream fis = new FileInputStream(file);
			BufferedInputStream bis = new BufferedInputStream(fis);
			File outFile = new File(copyPath);
			OutputStream ops = new FileOutputStream(outFile);
			BufferedOutputStream bos = new BufferedOutputStream(ops);
			byte[] b = new byte[1024];
			while (bis.read(b) != -1) {

				bos.write(b);
			}
			bos.flush();
			ops.close();
			bos.close();
			fis.close();
			bis.close();
		} else {
			System.out.println("文件不存在");
		}
		long endTime = System.currentTimeMillis();
		System.out.println("字节流操作--复制结束时间:" + sdf.format(new Date(endTime)));
	}

	/**
	 * 字符操作 复制文件夹
	 * @param savePath
	 * @param copyPath
	 * @throws Exception
	 */
	public static void filecopy(File sourceFile, File targetFile)
			throws Exception {
                if(!targetFile.exists()){
			targetFile.mkdir();
		}
		File tarpath = new File(targetFile, sourceFile.getName());
		
		if (sourceFile.isDirectory()) {
			tarpath.mkdir();
			File[] dir = sourceFile.listFiles();
			for (int i = 0; i < dir.length; i++) {
				filecopy(dir[i], tarpath);
			}
		} else {
			Reader reader = null;
			Writer writer = null;
			try {
				reader = new FileReader(sourceFile);
				writer = new FileWriter(tarpath);

				char[] buf = new char[1024];
				while (reader.read(buf) != -1) {
					writer.write(buf);
				}
			} finally {

				reader.close();
				writer.close();
			}
		}

	}

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		// FileIo.stream(SAVE_PATH);
		// FileIo.copy(SAVE_PATH, COPY_PATH);

		FileIo.filecopy(new File("E://java"), new File("E://新建文件夹"));

	}

}