檔案操作的一些Demo

文章目錄

• • • • • 周遊所有檔案
        • 讀寫檔案内容
        • 壓縮檔案
        • 解壓檔案

周遊所有檔案

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class Demo {
	public static List<String> fileList = new ArrayList<>(); // 檔案标準路徑的List集合
	
	/**
	 * 周遊目錄下所有檔案
	 * @param dirpath
	 * @throws IOException
	 */
	public static void traverseFiles(String dirpath) throws IOException {
		File dirFile = new File(dirpath);
		if (!dirFile.exists()) {
			return;
		}
		if (!dirFile.isDirectory()) {
			fileList.add(dirFile.getCanonicalPath());
			return;
		}
		String[] fileNames = dirFile.list();
		for (String string : fileNames) {
			File file = new File(dirFile.getCanonicalPath(), string);
			if (file.isDirectory()) {
				traverseFiles(file.getCanonicalPath());
			} else {
				fileList.add(file.getCanonicalPath());
			}
		}
	}
	
	/**
	 * 周遊Zip壓縮包中所有檔案
	 * @param dirpath
	 * @throws IOException
	 */
	public static void traverseZipFiles(String dirpath) throws IOException {
		ZipInputStream zin = new ZipInputStream(new BufferedInputStream(new FileInputStream(new File(zipath))));
		ZipEntry zipEntry;
		while ((zipEntry = zin.getNextEntry()) != null) {
			if (zipEntry.isDirectory()) {
			} else {
				fileList.add(zipEntry.getName());
			}
		}
		zin.close();
	}
}
           

讀寫檔案内容

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.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

public class Demo {
	/**
	 * 以位元組為機關讀寫檔案，常用于對二進制檔案的操作
	 * 
	 * @param rfilePath
	 * @param wfilePath
	 * @throws IOException
	 */
	public static void rwFileByBytes(String rfilePath, String wfilePath) throws IOException {
		File rFile = new File(rfilePath);
		if (!rFile.exists()) {
			return;
		}
		File wFile = new File(wfilePath);
		
		// 一次讀寫一個位元組
		BufferedInputStream bin = new BufferedInputStream(new FileInputStream(rFile));
		BufferedOutputStream bout = new BufferedOutputStream(new FileOutputStream(wFile));
		int nextByte;
		while ((nextByte = bin.read()) != -1) {
			bout.write(nextByte);
		}
		bin.close();
		bout.close();
		
		// 一次讀寫多個位元組，自建直接緩沖區
		InputStream in = new FileInputStream(rFile);
		OutputStream out = new FileOutputStream(wFile);
		byte[] temp = new byte[1024];
		int totalNum;
		while((totalNum = in.read(temp)) != -1) {
			out.write(temp, 0, totalNum);
		}
		in.close();
		out.close();
	}
	
	/**
	 * 以字元為機關讀寫機關, 常用于對文本檔案的操作
	 * 
	 * @param rfilePath
	 * @param wfilePath
	 * @throws IOException
	 */
	public static void rwFileByChars(String rfilePath, String wfilePath) throws IOException {
		File rFile = new File(rfilePath);
		if (!rFile.exists()) {
			return;
		}
		File wFile = new File(wfilePath);
		
		// 一次讀寫一個字元
		BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(rFile)));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(wFile)));
		int charRead;
		while((charRead = br.read()) != -1) {
			// 對于windows下，\r\n這兩個字元在一起時，表示一個換行。但如果這兩個字元分開顯示時，會換兩次行。是以，屏蔽掉\r，或者屏蔽\n。否則，将會多出很多空行。
			if (((char) charRead) != '\r') {
				bw.write(charRead);
			}
		}
		br.close();
		bw.close();
		
		// 一次讀寫多個字元, 自建直接緩沖區
		InputStreamReader reader = new InputStreamReader(new FileInputStream(rFile));
		OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(wFile));
		char[] temp = new char[256];
		int totalNum;
		while ((totalNum = reader.read(temp)) != -1) {
			if ((totalNum == temp.length) && (temp[temp.length - 1] != '\r')) {
				writer.write(temp, 0, totalNum);
            } else {
                for (int i = 0; i < totalNum; i++) {
                    if (temp[i] == '\r') {
                        continue;
                    } else {
                    	writer.write(temp[i]);
                    }
                }
            }
		}
		reader.close();
		writer.close();
	}
	
	/**
	 * 以行為機關讀寫檔案, 常用于讀寫面向行的格式化檔案
	 * 
	 * @param rfilePath
	 * @param wfilePath
	 * @throws IOException
	 */
	public static void rwFileByLines(String rfilePath, String wfilePath) throws IOException {
		File rFile = new File(rfilePath);
		if (!rFile.exists()) {
			return;
		}
		File wFile = new File(wfilePath);
		
		BufferedReader reader = new BufferedReader(new FileReader(rFile));
		BufferedWriter writer = new BufferedWriter(new FileWriter(wFile));
		// BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(rFile), "gbk"));
		// BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(wFile), "gbk"));
		String line = null;
		while ((line = reader.readLine()) != null) {
			writer.write(line);
		}
		reader.close();
		writer.close();
	}
}
           

壓縮檔案

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class Demo {
    /**
     * 壓縮方法
     *
     * @param file 要壓縮的檔案
     * @param zos zip輸出流
     * @param bos 輸出流
     * @param baseDir 要壓縮檔案所在檔案夾
     * @throws IOException
     */
    public static void compress(File file, ZipOutputStream zos, BufferedOutputStream bos, String baseDir) throws IOException {
        BufferedInputStream bis = null;
        try {
            if (!file.exists()) {
                return;
            }
            if (file.isFile()) {
                // 保證壓縮層次
                String entryPath = file.getCanonicalPath().replace(baseDir, "");
                // 建立一個要壓縮檔案的檔案名的條目
                ZipEntry entry = new ZipEntry(entryPath);
                // 将此條目放入建立好的壓縮包裡
                zos.putNextEntry(entry);
                byte[] buffer = new byte[4096];
                bis = new BufferedInputStream(new FileInputStream(file));
                int len;
                while ((len = bis.read(buffer)) > 0) {
                    bos.write(buffer, 0, len);
                    bos.flush();
                }
            } else {
                File[] files = file.listFiles();
                for (File f : files) {
                    compress(f, zos, bos, baseDir);
                }
            }
        } finally {
            if (null != bis) {
                bis.close();
            }
        }
    }

    /**
     * 建立zip壓縮檔案
     *
     * @param srcPath 要壓縮檔案所在檔案夾
     * @param desPath 生成的壓縮檔案
     * @return
     */
    public static File createZipFile(String srcPath, String desPath) {
        File file = new File(srcPath);
        if (!file.exists()) {
            return file;
        }
        File zipFile = new File(desPath);
        ZipOutputStream zos = null;
        BufferedOutputStream bos = null;
        try {
            zos = new ZipOutputStream(new FileOutputStream(zipFile));
            bos = new BufferedOutputStream(zos);
            compress(file, zos, bos, srcPath);
        } catch (FileNotFoundException e) {
            zipFile = null;
            e.printStackTrace();
        } catch (IOException e) {
            zipFile = null;
            e.printStackTrace();
        } finally {
            if (null != zos) {
                try {
                    zos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                try {
                    bos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return zipFile;
    }
}
           

解壓檔案

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

public class Demo {
    /**
     * 解壓zip壓縮包
     *
     * @param srcPath 壓縮包路徑
     * @param desPath 解壓路徑
     */
    public static void unZip(String srcPath, String desPath) {
        File srcFile = new File(srcPath);
        if (!srcFile.exists()) {
            return;
        }
        InputStream ins = null;
        FileOutputStream fos = null;
        try {
            ZipFile zipFile = new ZipFile(srcFile);
            Enumeration<?> entries = zipFile.entries();
            while (entries.hasMoreElements()) {
                ZipEntry entry = (ZipEntry) entries.nextElement();
                String path = desPath + File.separator + entry.getName();
                File file = new File(path);
                if (entry.isDirectory()) {
                    file.mkdirs();
                } else {
                    if (!file.getParentFile().exists()) {
                        file.getParentFile().mkdirs();
                    }
                    file.createNewFile();
                    ins = zipFile.getInputStream(entry);
                    fos = new FileOutputStream(file);
                    int len;
                    byte[] buffer = new byte[1024];
                    while ((len = ins.read(buffer)) != -1) {
                        fos.write(buffer, 0, len);
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != fos) {
                    fos.close();
                }
                if (null != ins) {
                    ins.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}
           

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