包含常用的文件操作，辅助开发
public class FileUtils {
// 获取指定文件的扩展名
public static String getFilenameExtension(String srcPath) {
// 将源路径转换成文件对象
File file = new File(srcPath);
if (file.isFile()) {
String name = file.getName();
String[] exName = name.split("\\.");
return exName[exName.length - 1];
} else {
return "";
}
}
/**
* 判断文件夹是否存在，如不存在则创建
*/
public static void isFolderExitAndCreate(String folderName){
File file = new File(folderName);
if(!file.exists()){
file.mkdir();
}
}
/**
* 获取文件MD5值
*
* @param file
* @return 文件的MD5字符串
*/
public static String getMd5ByFile(File file) {
String value = null;
FileInputStream in = null;
try {
in = new FileInputStream(file);
MappedByteBuffer byteBuffer = in.getChannel().map(FileChannel.MapMode.READ_ONLY, 0,
file.length());
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(byteBuffer);
BigInteger bi = new BigInteger(1, md5.digest());
value = bi.toString(16);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (null != in) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return value;
}
/**
* 获取文件总的大小
*
* @param file 文件
* @return 文件长度
*/
public static long getFileLength(File file)
throws IOException {
FileInputStream fis = null;
fis = new FileInputStream(file);
return fis.available();
}
/**
* rename 文件重命名
*
* @param to
* @param from
* @return
*/
public static File rename(File from, File to) {
try {
String newPath = to.getPath();
String oldPath = from.getPath();
if (!oldPath.equals(newPath)) {
if (!to.exists()) {
from.renameTo(to);
}
}
} catch (Exception ex) {
}
return to;
}
/**
* rename 文件重命名
*
* @param filePath
* @param from
* @param to
* @return
*/
public static File rename(String filePath, String from, String to) {
File newFile = null;
try {
File oldFile = new File(combainPath(filePath, from));
newFile = new File(combainPath(filePath, to));
rename(newFile, oldFile);
} catch (Exception ex) {
}
return newFile;
}
/**
* 读取文件到二进制
* @param file
* @return
* @throws IOException
*/
public static byte[] getBytesFromFile(File file)
throws IOException {
InputStream is = new FileInputStream(file);
long length = file.length();
if (length > Integer.MAX_VALUE) {
// File is too large
}
byte[] bytes = new byte[(int) length];
// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
offset += numRead;
}
// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("不能读取文件: " + file.getName());
}
is.close();
return bytes;
}
/**
* 获取标准文件大小，以KB，MB，GB结尾
*
* @param file
* @return 以KB，MB，GB结尾字符串文件大小
* @throws IOException
*/
public static String getFileSize(File file)
throws IOException {
if (size < 1024) {
return String.valueOf(size) + "B";
} else {
size = size / 1024;
}
if (size < 1024) {
return String.valueOf(size) + "KB";
} else {
size = size / 1024;
}
if (size < 1024) {
size = size * 100;
return String.valueOf((size / 100)) + "."
+ String.valueOf((size % 100)) + "MB";
} else {
size = size * 100 / 1024;
return String.valueOf((size / 100)) + "."
+ String.valueOf((size % 100)) + "GB";
}
}
/**
* 检查文件是否存在
*
* @param fileName
* @return
* @throws IOException
*/
public static boolean existFile(String fileName)
throws IOException {
File file = new File(fileName);
if (!file.exists()) {
throw new IOException("文件未找到:" + fileName);
}
return file.exists();
}
/**
* 删除文件
*
* @param fileName
*/
public static void deleteFile(String fileName)
throws IOException {
File file = new File(fileName);
if (!file.exists()) {
throw new IOException("文件未找到:" + fileName);
}
file.delete();
}
/**
* 读取文件到字符串
*
* @param fileName
* @return
* @throws IOException
*/
public static String readFile(String fileName)
throws IOException {
File file = new File(fileName);
if (!file.exists()) {
throw new IOException("文件未找到:" + fileName);
}
BufferedReader in = new BufferedReader(new FileReader(file));
StringBuffer sb = new StringBuffer();
String str = "";
while ((str = in.readLine()) != null) {
sb.append(str);
}
in.close();
return sb.toString();
}
/**
* 删除文件夹
*
* @param folderPath
* 文件夹路径
*/
public static void delFolder(String folderPath) {
// 删除文件夹里面所有内容
delAllFile(folderPath);
String filePath = folderPath;
java.io.File myFilePath = new java.io.File(filePath);
// 删除空文件夹
myFilePath.delete();
}
/**
* 删除文件夹里面的所有文件
*
* @param path
* 文件夹路径
*/
public static void delAllFile(String path) {
File file = new File(path);
if (!file.exists()) {
return;
}
if (!file.isDirectory()) {
return;
}
String[] childFiles = file.list();
File temp = null;
for (int i = 0; i < childFiles.length; i++) {
if (path.endsWith(File.separator)) {
temp = new File(path + childFiles[i]);
} else {
temp = new File(path + File.separator + childFiles[i]);
}
if (temp.isFile()) {
temp.delete();
}
if (temp.isDirectory()) {
delAllFile(path + File.separatorChar + childFiles[i]);// 先删除文件夹里面的文件
delFolder(path + File.separatorChar + childFiles[i]);// 再删除空文件夹
}
}
}
/**
* 复制单个文件
* @param srcFileName 待复制的文件名
* @param descFileName 目标文件名
* @param coverlay 如果目标文件已存在，是否覆盖
* @return 如果复制成功，则返回true，否则返回false
*/
public static boolean copyFile(String srcFileName,
String descFileName, boolean coverlay) {
File srcFile = new File(srcFileName);
if (!srcFile.exists()) {
return false;
}
else if (!srcFile.isFile()) {
return false;
}
File descFile = new File(descFileName);
// 判断目标文件是否存在
if (descFile.exists()) {
// 如果目标文件存在，并且允许覆盖
if (coverlay) {
if (!FileUtils.delFile(descFileName)) {
return false;
}
} else {
return false;
}
} else {
if (!descFile.getParentFile().exists()) {
// 如果目标文件所在的目录不存在，则创建目录
if (!descFile.getParentFile().mkdirs()) {
return false;
}
}
}
// 复制文件
int readByte = 0;
InputStream ins = null;
OutputStream outs = null;
try {
// 打开源文件
ins = new FileInputStream(srcFile);
// 打开目标文件的输出流
outs = new FileOutputStream(descFile);
byte[] buf = new byte[1024];
while ((readByte = ins.read(buf)) != -1) {
// 将读取的字节流写入到输出流
outs.write(buf, 0, readByte);
}
return true;
} catch (Exception e) {
return false;
} finally {
// 关闭输入输出流，首先关闭输出流，然后再关闭输入流
if (outs != null) {
try {
outs.close();
} catch (IOException oute) {
oute.printStackTrace();
}
}
if (ins != null) {
try {
ins.close();
} catch (IOException ine) {
ine.printStackTrace();
}
}
}
}
/**
* 复制文件夹
*
* @param oldPath
* String 源文件夹路径 如
* @param newPath
* String 目标文件夹路径
* @return boolean
*/
public static void copyFolder(String oldPath, String newPath)
throws IOException {
// 如果文件夹不存在 则新建文件夹
mkdir(newPath);
File file = new File(oldPath);
String[] files = file.list();
File temp = null;
for (int i = 0; i < files.length; i++) {
if (oldPath.endsWith(File.separator)) {
temp = new File(oldPath + files[i]);
} else {
temp = new File(oldPath + File.separator + files[i]);
}
if (temp.isFile()) {
FileInputStream input = new FileInputStream(temp);
FileOutputStream output = new FileOutputStream(newPath + "/"
+ (temp.getName()).toString());
byte[] buffer = new byte[1024 * 2];
int len;
while ((len = input.read(buffer)) != -1) {
output.write(buffer, 0, len);
}
output.flush();
output.close();
input.close();
}
if (temp.isDirectory()) {// 如果是子文件夹
copyFolder(oldPath + "/" + files[i], newPath + "/" + files[i]);
}
}
}
/**
* 移动文件到指定目录
*
* @param oldPath
* 包含路径的文件名
* @param newPath
* 目标文件目录
*/
public static void moveFile(String oldPath, String newPath)
throws IOException {
copyFile(oldPath, newPath);
deleteFile(oldPath);
}
/**
* 移动文件到指定目录，不会删除文件夹
*
* @param oldPath
* 源文件目录
* @param newPath
* 目标文件目录
*/
public static void moveFiles(String oldPath, String newPath)
throws IOException {
copyFolder(oldPath, newPath);
delAllFile(oldPath);
}
/**
* 移动文件到指定目录，会删除文件夹
*
* @param oldPath
* 源文件目录
* @param newPath
* 目标文件目录
*/
public static void moveFolder(String oldPath, String newPath)
throws IOException {
copyFolder(oldPath, newPath);
delFolder(oldPath);
}
/**
* 读取数据
*
* @param inSream
* @param charsetName
* @return
* @throws Exception
*/
public static String readData(InputStream inSream, String charsetName)
throws IOException {
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = -1;
while ((len = inSream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
}
byte[] data = outStream.toByteArray();
outStream.close();
inSream.close();
return new String(data, charsetName);
}
/**
* 一行一行读取文件，适合字符读取，若读取中文字符时会出现乱码
*
* @param path
* @return
* @throws Exception
*/
public static Set<String> readFileLine(String path)
throws IOException {
Set<String> datas = new HashSet<String>();
FileReader fr = new FileReader(path);
BufferedReader br = new BufferedReader(fr);
String line = null;
while ((line = br.readLine()) != null) {
datas.add(line);
}
br.close();
fr.close();
return datas;
}
}
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