JAVA工具类------文件工具类fileUtil
参考于：
https://blog.csdn.net/lovoo/article/details/77899627
https://blog.csdn.net/u014315849/article/details/50804554
在网上找了两个写好的工具类
版本一：
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
/**
* @ClassName
* @Description 文件操作工具剋
* @Date 2018-12-13 10:36
**/
public class FileUtil {
/**
* 读取文件内容
*
* @param is
* @return
*/
public static String readFile(InputStream is) {
BufferedReader br = null;
StringBuffer sb = new StringBuffer();
try {
br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
String readLine = null;
while ((readLine = br.readLine()) != null) {
sb.append(readLine);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
br.close();
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
/**
* 判断指定的文件是否存在。
*
* @param fileName
* @return
*/
public static boolean isFileExist(String fileName) {
return new File(fileName).isFile();
}
/**
* 创建指定的目录。 如果指定的目录的父目录不存在则创建其目录书上所有需要的父目录。
* 注意：可能会在返回false的时候创建部分父目录。
*
* @param file
* @return
*/
public static boolean makeDirectory(File file) {
File parent = file.getParentFile();
if (parent != null) {
return parent.mkdirs();
}
return false;
}
/**
* 返回文件的URL地址。
*
* @param file
* @return
* @throws MalformedURLException
*/
public static URL getURL(File file) throws MalformedURLException {
String fileURL = "file:/" + file.getAbsolutePath();
URL url = new URL(fileURL);
return url;
}
/**
* 从文件路径得到文件名。
*
* @param filePath
* @return
*/
public static String getFileName(String filePath) {
File file = new File(filePath);
return file.getName();
}
/**
* 从文件名得到文件绝对路径。
*
* @param fileName
* @return
*/
public static String getFilePath(String fileName) {
File file = new File(fileName);
return file.getAbsolutePath();
}
/**
* 将DOS/Windows格式的路径转换为UNIX/Linux格式的路径。
*
* @param filePath
* @return
*/
public static String toUNIXpath(String filePath) {
return filePath.replace("", "/");
}
/**
* 从文件名得到UNIX风格的文件绝对路径。
*
* @param fileName
* @return
*/
public static String getUNIXfilePath(String fileName) {
File file = new File(fileName);
return toUNIXpath(file.getAbsolutePath());
}
/**
* 得到文件后缀名
*
* @param fileName
* @return
*/
public static String getFileExt(String fileName) {
int point = fileName.lastIndexOf('.');
int length = fileName.length();
if (point == -1 || point == length - 1) {
return "";
} else {
return fileName.substring(point + 1, length);
}
}
/**
* 得到文件的名字部分。 实际上就是路径中的最后一个路径分隔符后的部分。
*
* @param fileName
* @return
*/
public static String getNamePart(String fileName) {
int point = getPathLastIndex(fileName);
int length = fileName.length();
if (point == -1) {
return fileName;
} else if (point == length - 1) {
int secondPoint = getPathLastIndex(fileName, point - 1);
if (secondPoint == -1) {
if (length == 1) {
return fileName;
} else {
return fileName.substring(0, point);
}
} else {
return fileName.substring(secondPoint + 1, point);
}
} else {
return fileName.substring(point + 1);
}
}
/**
* 得到文件名中的父路径部分。 对两种路径分隔符都有效。 不存在时返回""。
* 如果文件名是以路径分隔符结尾的则不考虑该分隔符，例如"/path/"返回""。
*
* @param fileName
* @return
*/
public static String getPathPart(String fileName) {
int point = getPathLastIndex(fileName);
int length = fileName.length();
if (point == -1) {
return "";
} else if (point == length - 1) {
int secondPoint = getPathLastIndex(fileName, point - 1);
if (secondPoint == -1) {
return "";
} else {
return fileName.substring(0, secondPoint);
}
} else {
return fileName.substring(0, point);
}
}
/**
* 得到路径分隔符在文件路径中最后出现的位置。 对于DOS或者UNIX风格的分隔符都可以。
*
* @param fileName
* @return
*/
public static int getPathLastIndex(String fileName) {
int point = fileName.lastIndexOf("/");
if (point == -1) {
point = fileName.lastIndexOf("");
}
return point;
}
/**
* 得到路径分隔符在文件路径中指定位置前最后出现的位置。 对于DOS或者UNIX风格的分隔符都可以。
*
* @param fileName
* @param fromIndex
* @return
*/
public static int getPathLastIndex(String fileName, int fromIndex) {
int point = fileName.lastIndexOf("/", fromIndex);
if (point == -1) {
point = fileName.lastIndexOf("", fromIndex);
}
return point;
}
/**
* 得到路径分隔符在文件路径中首次出现的位置。 对于DOS或者UNIX风格的分隔符都可以。
*
* @param fileName
* @return
*/
public static int getPathIndex(String fileName) {
int point = fileName.indexOf("/");
if (point == -1) {
point = fileName.indexOf("");
}
return point;
}
/**
* 得到路径分隔符在文件路径中指定位置后首次出现的位置。 对于DOS或者UNIX风格的分隔符都可以。
*
* @param fileName
* @param fromIndex
* @return
*/
public static int getPathIndex(String fileName, int fromIndex) {
int point = fileName.indexOf("/", fromIndex);
if (point == -1) {
point = fileName.indexOf("", fromIndex);
}
return point;
}
/**
* 将文件名中的类型部分去掉。
*
* @param filename
* @return
*/
public static String removeFileExt(String filename) {
int index = filename.lastIndexOf(".");
if (index != -1) {
return filename.substring(0, index);
} else {
return filename;
}
}
/**
* 得到相对路径。 文件名不是目录名的子节点时返回文件名。
*
* @param pathName
* @param fileName
* @return
*/
public static String getSubpath(String pathName, String fileName) {
int index = fileName.indexOf(pathName);
if (index != -1) {
return fileName.substring(index + pathName.length() + 1);
} else {
return fileName;
}
}
/**
* 删除一个文件。
*
* @param filename
* @throws IOException
*/
public static void deleteFile(String filename) throws IOException {
File file = new File(filename);
if (file.isDirectory()) {
throw new IOException("IOException -> BadInputException: not a file.");
}
if (!file.exists()) {
throw new IOException("IOException -> BadInputException: file is not exist.");
}
if (!file.delete()) {
throw new IOException("Cannot delete file. filename = " + filename);
}
}
/**
* 删除文件夹及其下面的子文件夹
*
* @param dir
* @throws IOException
*/
public static void deleteDir(File dir) throws IOException {
if (dir.isFile())
throw new IOException("IOException -> BadInputException: not a directory.");
File[] files = dir.listFiles();
if (files != null) {
for (int i = 0; i < files.length; i++) {
File file = files[i];
if (file.isFile()) {
file.delete();
} else {
deleteDir(file);
}
}
}
dir.delete();
}
/**
* 复制文件
*
* @param src
* @param dst
* @throws Exception
*/
public static void copy(File src, File dst) throws Exception {
int BUFFER_SIZE = 4096;
InputStream in = null;
OutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(src), BUFFER_SIZE);
out = new BufferedOutputStream(new FileOutputStream(dst), BUFFER_SIZE);
byte[] buffer = new byte[BUFFER_SIZE];
int len = 0;
while ((len = in.read(buffer)) > 0) {
out.write(buffer, 0, len);
}
} catch (Exception e) {
throw e;
} finally {
if (null != in) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
in = null;
}
if (null != out) {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
out = null;
}
}
}
/**
* @复制文件，支持把源文件内容追加到目标文件末尾
* @param src
* @param dst
* @param append
* @throws Exception
*/
public static void copy(File src, File dst, boolean append) throws Exception {
int BUFFER_SIZE = 4096;
InputStream in = null;
OutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(src), BUFFER_SIZE);
out = new BufferedOutputStream(new FileOutputStream(dst, append), BUFFER_SIZE);
byte[] buffer = new byte[BUFFER_SIZE];
int len = 0;
while ((len = in.read(buffer)) > 0) {
out.write(buffer, 0, len);
}
} catch (Exception e) {
throw e;
} finally {
if (null != in) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
in = null;
}
if (null != out) {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
out = null;
}
}
}
}
版本二：
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;/**
* File Utils
*
* Read or write file
*- {@link #readFile(String, String)} read file
*- {@link #readFileToList(String, String)} read file to string list
*- {@link #writeFile(String, String, boolean)} write file from String
*- {@link #writeFile(String, String)} write file from String
*- {@link #writeFile(String, List, boolean)} write file from String List
*- {@link #writeFile(String, List)} write file from String List
*- {@link #writeFile(String, InputStream)} write file
*- {@link #writeFile(String, InputStream, boolean)} write file
*- {@link #writeFile(File, InputStream)} write file
*- {@link #writeFile(File, InputStream, boolean)} write file
*
*
* Operate file
*- {@link #moveFile(File, File)}
*- {@link #copyFile(String, String)}
*- {@link #getFileExtension(String)}
*- {@link #getFileName(String)}
*- {@link #getFileNameWithoutExtension(String)}
*- {@link #getFileSize(String)}
*- {@link #deleteFile(String)}
*- {@link #isFileExist(String)}
*- {@link #isFolderExist(String)}
*- {@link #makeFolders(String)}
*- {@link #makeDirs(String)}
*
*
* @author Trinea 2012-5-12
*/
public class FileUtils {public final static String FILE_EXTENSION_SEPARATOR = ".";
private FileUtils() {
throw new AssertionError();
}/**
* read file
*
* @param filePath
* @param charsetName The name of a supported {@link java.nio.charset.Charset charset}
* @return if file not exist, return null, else return content of file
* @throws RuntimeException if an error occurs while operator BufferedReader
*/
public static StringBuilder readFile(String filePath, String charsetName) {
File file = new File(filePath);
StringBuilder fileContent = new StringBuilder("");
if (file == null || !file.isFile()) {
return null;
}BufferedReader reader = null;
try {
InputStreamReader is = new InputStreamReader(new FileInputStream(file), charsetName);
reader = new BufferedReader(is);
String line = null;
while ((line = reader.readLine()) != null) {
if (!fileContent.toString().equals("")) {
fileContent.append("\r\n");
}
fileContent.append(line);
}
return fileContent;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(reader);
}
}/**
* write file
*
* @param filePath
* @param content
* @param append is append, if true, write to the end of file, else clear content of file and write into it
* @return return false if content is empty, true otherwise
* @throws RuntimeException if an error occurs while operator FileWriter
*/
public static boolean writeFile(String filePath, String content, boolean append) {
if (StringUtils.isEmpty(content)) {
return false;
}FileWriter fileWriter = null;
try {
makeDirs(filePath);
fileWriter = new FileWriter(filePath, append);
fileWriter.write(content);
return true;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(fileWriter);
}
}/**
* write file
*
* @param filePath
* @param contentList
* @param append is append, if true, write to the end of file, else clear content of file and write into it
* @return return false if contentList is empty, true otherwise
* @throws RuntimeException if an error occurs while operator FileWriter
*/
public static boolean writeFile(String filePath, ListcontentList, boolean append) {
if (ListUtils.isEmpty(contentList)) {
return false;
}FileWriter fileWriter = null;
try {
makeDirs(filePath);
fileWriter = new FileWriter(filePath, append);
int i = 0;
for (String line : contentList) {
if (i++ > 0) {
fileWriter.write("\r\n");
}
fileWriter.write(line);
}
return true;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(fileWriter);
}
}/**
* write file, the string will be written to the begin of the file
*
* @param filePath
* @param content
* @return
*/
public static boolean writeFile(String filePath, String content) {
return writeFile(filePath, content, false);
}/**
* write file, the string list will be written to the begin of the file
*
* @param filePath
* @param contentList
* @return
*/
public static boolean writeFile(String filePath, ListcontentList) {
return writeFile(filePath, contentList, false);
}/**
* write file, the bytes will be written to the begin of the file
*
* @param filePath
* @param stream
* @return
* @see {@link #writeFile(String, InputStream, boolean)}
*/
public static boolean writeFile(String filePath, InputStream stream) {
return writeFile(filePath, stream, false);
}/**
* write file
*
* @param file the file to be opened for writing.
* @param stream the input stream
* @param append iftrue, then bytes will be written to the end of the file rather than the beginning
* @return return true
* @throws RuntimeException if an error occurs while operator FileOutputStream
*/
public static boolean writeFile(String filePath, InputStream stream, boolean append) {
return writeFile(filePath != null ? new File(filePath) : null, stream, append);
}/**
* write file, the bytes will be written to the begin of the file
*
* @param file
* @param stream
* @return
* @see {@link #writeFile(File, InputStream, boolean)}
*/
public static boolean writeFile(File file, InputStream stream) {
return writeFile(file, stream, false);
}/**
* write file
*
* @param file the file to be opened for writing.
* @param stream the input stream
* @param append iftrue, then bytes will be written to the end of the file rather than the beginning
* @return return true
* @throws RuntimeException if an error occurs while operator FileOutputStream
*/
public static boolean writeFile(File file, InputStream stream, boolean append) {
OutputStream o = null;
try {
makeDirs(file.getAbsolutePath());
o = new FileOutputStream(file, append);
byte data[] = new byte[1024];
int length = -1;
while ((length = stream.read(data)) != -1) {
o.write(data, 0, length);
}
o.flush();
return true;
} catch (FileNotFoundException e) {
throw new RuntimeException("FileNotFoundException occurred. ", e);
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(o);
IOUtils.close(stream);
}
}/**
* move file
*
* @param srcFile
* @param destFile
*/
public static void moveFile(File srcFile, File destFile) {
boolean rename = srcFile.renameTo(destFile);
if (!rename) {
copyFile(srcFile.getAbsolutePath(), destFile.getAbsolutePath());
deleteFile(srcFile.getAbsolutePath());
}
}/**
* copy file
*
* @param sourceFilePath
* @param destFilePath
* @return
* @throws RuntimeException if an error occurs while operator FileOutputStream
*/
public static boolean copyFile(String sourceFilePath, String destFilePath) {
InputStream inputStream = null;
try {
inputStream = new FileInputStream(sourceFilePath);
} catch (FileNotFoundException e) {
throw new RuntimeException("FileNotFoundException occurred. ", e);
}
return writeFile(destFilePath, inputStream);
}/**
* read file to string list, a element of list is a line
*
* @param filePath
* @param charsetName The name of a supported {@link java.nio.charset.Charset charset}
* @return if file not exist, return null, else return content of file
* @throws RuntimeException if an error occurs while operator BufferedReader
*/
public static ListreadFileToList(String filePath, String charsetName) {
File file = new File(filePath);
ListfileContent = new ArrayList ();
if (file == null || !file.isFile()) {
return null;
}BufferedReader reader = null;
try {
InputStreamReader is = new InputStreamReader(new FileInputStream(file), charsetName);
reader = new BufferedReader(is);
String line = null;
while ((line = reader.readLine()) != null) {
fileContent.add(line);
}
return fileContent;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(reader);
}
}/**
* get file name from path, not include suffix
*
*
* getFileNameWithoutExtension(null) = null
* getFileNameWithoutExtension("") = ""
* getFileNameWithoutExtension(" ") = " "
* getFileNameWithoutExtension("abc") = "abc"
* getFileNameWithoutExtension("a.mp3") = "a"
* getFileNameWithoutExtension("a.b.rmvb") = "a.b"
* getFileNameWithoutExtension("c:\\") = ""
* getFileNameWithoutExtension("c:\\a") = "a"
* getFileNameWithoutExtension("c:\\a.b") = "a"
* getFileNameWithoutExtension("c:a.txt\\a") = "a"
* getFileNameWithoutExtension("/home/admin") = "admin"
* getFileNameWithoutExtension("/home/admin/a.txt/b.mp3") = "b"
*
*
* @param filePath
* @return file name from path, not include suffix
* @see
*/
public static String getFileNameWithoutExtension(String filePath) {
if (StringUtils.isEmpty(filePath)) {
return filePath;
}int extenPosi = filePath.lastIndexOf(FILE_EXTENSION_SEPARATOR);
int filePosi = filePath.lastIndexOf(File.separator);
if (filePosi == -1) {
return (extenPosi == -1 ? filePath : filePath.substring(0, extenPosi));
}
if (extenPosi == -1) {
return filePath.substring(filePosi + 1);
}
return (filePosi < extenPosi ? filePath.substring(filePosi + 1, extenPosi) : filePath.substring(filePosi + 1));
}/**
* get file name from path, include suffix
*
*
* getFileName(null) = null
* getFileName("") = ""
* getFileName(" ") = " "
* getFileName("a.mp3") = "a.mp3"
* getFileName("a.b.rmvb") = "a.b.rmvb"
* getFileName("abc") = "abc"
* getFileName("c:\\") = ""
* getFileName("c:\\a") = "a"
* getFileName("c:\\a.b") = "a.b"
* getFileName("c:a.txt\\a") = "a"
* getFileName("/home/admin") = "admin"
* getFileName("/home/admin/a.txt/b.mp3") = "b.mp3"
*
*
* @param filePath
* @return file name from path, include suffix
*/
public static String getFileName(String filePath) {
if (StringUtils.isEmpty(filePath)) {
return filePath;
}int filePosi = filePath.lastIndexOf(File.separator);
return (filePosi == -1) ? filePath : filePath.substring(filePosi + 1);
}/**
* get folder name from path
*
*
* getFolderName(null) = null
* getFolderName("") = ""
* getFolderName(" ") = ""
* getFolderName("a.mp3") = ""
* getFolderName("a.b.rmvb") = ""
* getFolderName("abc") = ""
* getFolderName("c:\\") = "c:"
* getFolderName("c:\\a") = "c:"
* getFolderName("c:\\a.b") = "c:"
* getFolderName("c:a.txt\\a") = "c:a.txt"
* getFolderName("c:a\\b\\c\\d.txt") = "c:a\\b\\c"
* getFolderName("/home/admin") = "/home"
* getFolderName("/home/admin/a.txt/b.mp3") = "/home/admin/a.txt"
*
*
* @param filePath
* @return
*/
public static String getFolderName(String filePath) {if (StringUtils.isEmpty(filePath)) {
return filePath;
}int filePosi = filePath.lastIndexOf(File.separator);
return (filePosi == -1) ? "" : filePath.substring(0, filePosi);
}/**
* get suffix of file from path
*
*
* getFileExtension(null) = ""
* getFileExtension("") = ""
* getFileExtension(" ") = " "
* getFileExtension("a.mp3") = "mp3"
* getFileExtension("a.b.rmvb") = "rmvb"
* getFileExtension("abc") = ""
* getFileExtension("c:\\") = ""
* getFileExtension("c:\\a") = ""
* getFileExtension("c:\\a.b") = "b"
* getFileExtension("c:a.txt\\a") = ""
* getFileExtension("/home/admin") = ""
* getFileExtension("/home/admin/a.txt/b") = ""
* getFileExtension("/home/admin/a.txt/b.mp3") = "mp3"
*
*
* @param filePath
* @return
*/
public static String getFileExtension(String filePath) {
if (StringUtils.isBlank(filePath)) {
return filePath;
}int extenPosi = filePath.lastIndexOf(FILE_EXTENSION_SEPARATOR);
int filePosi = filePath.lastIndexOf(File.separator);
if (extenPosi == -1) {
return "";
}
return (filePosi >= extenPosi) ? "" : filePath.substring(extenPosi + 1);
}/**
* Creates the directory named by the trailing filename of this file, including the complete directory path required
* to create this directory.
*
*
* Attentions:
*- makeDirs("C:\\Users\\Trinea") can only create users folder
*- makeFolder("C:\\Users\\Trinea\\") can create Trinea folder
*
*
* @param filePath
* @return true if the necessary directories have been created or the target directory already exists, false one of
* the directories can not be created.
*
*- if {@link FileUtils#getFolderName(String)} return null, return false
*- if target directory already exists, return true
*- return {@link File#makeFolder}
*
*/
public static boolean makeDirs(String filePath) {
String folderName = getFolderName(filePath);
if (StringUtils.isEmpty(folderName)) {
return false;
}File folder = new File(folderName);
return (folder.exists() && folder.isDirectory()) ? true : folder.mkdirs();
}/**
* @param filePath
* @return
* @see #makeDirs(String)
*/
public static boolean makeFolders(String filePath) {
return makeDirs(filePath);
}/**
* Indicates if this file represents a file on the underlying file system.
*
* @param filePath
* @return
*/
public static boolean isFileExist(String filePath) {
if (StringUtils.isBlank(filePath)) {
return false;
}File file = new File(filePath);
return (file.exists() && file.isFile());
}/**
* Indicates if this file represents a directory on the underlying file system.
*
* @param directoryPath
* @return
*/
public static boolean isFolderExist(String directoryPath) {
if (StringUtils.isBlank(directoryPath)) {
return false;
}File dire = new File(directoryPath);
return (dire.exists() && dire.isDirectory());
}/**
* delete file or directory
*
*- if path is null or empty, return true
*- if path not exist, return true
*- if path exist, delete recursion. return true
*
*
* @param path
* @return
*/
public static boolean deleteFile(String path) {
if (StringUtils.isBlank(path)) {
return true;
}File file = new File(path);
if (!file.exists()) {
return true;
}
if (file.isFile()) {
return file.delete();
}
if (!file.isDirectory()) {
return false;
}
for (File f : file.listFiles()) {
if (f.isFile()) {
f.delete();
} else if (f.isDirectory()) {
deleteFile(f.getAbsolutePath());
}
}
return file.delete();
}/**
* get file size
*
*- if path is null or empty, return -1
*- if path exist and it is a file, return file size, else return -1
*
*
* @param path
* @return returns the length of this file in bytes. returns -1 if the file does not exist.
*/
public static long getFileSize(String path) {
if (StringUtils.isBlank(path)) {
return -1;
}File file = new File(path);
return (file.exists() && file.isFile() ? file.length() : -1);
}
}