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This article will explain in detail what are the commonly used file manipulation methods in java. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.

Common operation methods of files

Public class FileUtility {

/ * *

* create a directory

*

* @ param fileDir

* the directory where the file is located

*

* @ throws java.lang.Exception

, /

Public static void createDir (String filePath) {

File fileDir = new File (filePath)

Try {

If (! fileDir.exists ()) {

FileDir.mkdir ()

}

} catch (Exception ex) {

}

}

/ * *

* @ roseuid 46345A88024A

, /

Public FileUtility () {

}

/ * *

* if the file exists, delete it and recreate it; if it does not exist, create it.

*

* @ param filePath-

* File path

* @ param fileName-

* File name

* @ param sb-

* output content

* @ roseuid 4612F3C103B9

, /

Public static void createFile (String filePath, String fileName

StringBuffer sb) {

CreateDir (filePath)

Java.io.File file = new java.io.File (filePath, fileName)

Try {

If (file.exists ()) = = true) {

File = new java.io.File (filePath, fileName)

File.delete ()

}

File.createNewFile ()

FileOutputStream fos = new FileOutputStream (file)

Writer out = new OutputStreamWriter (fos, "GB2312")

Out.write (sb.toString ())

Out.flush ()

Out.close ()

Fos.close ()

Out = null

Fos = null

} catch (Exception ex) {

}

}

/ * *

* Delete files

*

* @ param filePath-

* File path

* @ param fileName-

* File name

* @ roseuid 4612F3C103B9

, /

Public static void deleteFile (String filePath, String fileName)

{

CreateDir (filePath)

Java.io.File file = new java.io.File (filePath, fileName)

Try {

If (file.exists ()) {

File = new java.io.File (filePath, fileName)

File.delete ()

}

File = null

} catch (Exception ex) {

}

}

/ * *

* create a new file

* @ param filePath

* @ param fileName

, /

Public static void createOrClearFile (String filePath, String fileName)

{

CreateDir (filePath)

File fileDS = new File (filePath, fileName)

Try {

If (fileDS.exists ()) {

FileDS = new File (filePath, fileName)

FileDS.delete ()

}

FileDS.createNewFile ()

} catch (Exception ex) {

}

}

/ * *

* add content to the document

* @ param filePath

* @ param fileName

* @ param sb

, /

Public static void writeAppendFile (String filePath, String fileName

StringBuffer sb) {

Try {

FileWriter fileWriter = new FileWriter (filePath + File.separator

+ fileName, true)

PrintWriter out = new PrintWriter (fileWriter)

Out.print (sb.toString ())

Out.flush ()

FileWriter.flush ()

Out.close ()

FileWriter.close ()

Out = null

FileWriter = null

} catch (Exception ex) {

}

}

/ * *

* compress the files in the specified directory

*

* @ param zipList-

* File name, the file name in the list is compressed into a compressed package

* @ param filePath-

* File path

* @ param zipName-

* name of the compressed file

* @ roseuid 4612F4AE03B1

, /

Public static void zip (List zipList, String filePath, String zipName)

{

BufferedInputStream origin = null

ZipOutputStream out = null

Int BUFFER = 2048

CreateDir (filePath)

Try {

File zipFile = new File (filePath, zipName)

FileOutputStream dest = new FileOutputStream (zipFile)

Byte data [] = new byte [BUFFER]

/ / enter the flag bit for the compressed file, judge whether it is damaged when decompressing, and do not decompress if it is damaged.

Out = new ZipOutputStream (new BufferedOutputStream (dest))

/ / set the file to be compressed

Out.setMethod (ZipOutputStream.DEFLATED)

Int num = zipList.size ()

For (int I = 0; I

< num; i++) { FileInputStream fi = new FileInputStream(filePath + File.separator + (String) zipList.get(i)); origin = new BufferedInputStream(fi, BUFFER); ZipEntry entry = new ZipEntry((String) zipList.get(i)); out.putNextEntry(entry); int count; while ((count = origin.read(data, 0, BUFFER)) != -1) { out.write(data, 0, count); } origin.close(); } out.close(); } catch (Exception e) { } finally { origin = null; out = null; } } /** * 删除临时文件 * * @param delList - * 要删除的文件的名称的列表 * @param filePath - * 删除文件的路径 * @roseuid 4612F5380341 */ public static void delete(List delList, String filePath) { try { for (int i = 0; i < delList.size(); i++) { String fileName = (String) delList.get(i); File f = new File(filePath, fileName); if (f.exists()) { f.delete(); } fileName = null; f = null; } } catch (Exception e) { } } /** * 从zip文件中获取指定名称的文件 * * @param filePath - * zip所在文件目录 * @param zipFileName - * zip文件名称 * @param fileName - * 要读出的文件名称 * @return BufferedReader * @roseuid 4612F788032E */ public static BufferedReader getZipReader(String filePath, String zipFileName, String fileName) { BufferedReader br = null; try { ZipFile zf = new ZipFile(filePath + File.separator + zipFileName); ZipEntry entry = zf.getEntry(fileName); br = new BufferedReader(new InputStreamReader(zf .getInputStream(entry))); } catch (Exception e) { } return br; } public static Document readXmlFile(File xmlFile) { Document doc = null; try { SAXBuilder saxBuilder = new org.jdom.input.SAXBuilder(false); doc = saxBuilder.build(xmlFile); } catch (Exception ex) { } return doc; } /** * 保存导出文件 * * @param saveDir * String * @param fileName * String * @param doc * Document */ public static void saveXmlFile(String saveDir, String fileName, Document doc) { createDir(saveDir); try { java.io.FileWriter fw = null; java.io.BufferedWriter bw = null; File file = new File(saveDir, fileName); if (file.exists()) { file.delete(); } if (file.createNewFile()) { XMLOutputter xmlOut = new XMLOutputter(" ", true); xmlOut.setEncoding("GB2312"); fw = new java.io.FileWriter(file); bw = new java.io.BufferedWriter(fw); xmlOut.output(doc, bw); bw.flush(); fw.flush(); bw.close(); fw.close(); bw = null; fw = null; } } catch (Exception ex) { } } public static void createEntryFile() { try { // 创建xml文件 Element rootElement = new Element("entry"); Document doc = new Document(rootElement); FileUtility.saveXmlFile(FilePath, FileName, doc); } catch (Exception e) { } } public void zip(List tableList, String entryFileName, String backupFilePath, String backupFileName){ // 1.获取所有的压缩文件名 List fileList = new ArrayList(); int num = tableList.size(); TableObject to = null; for (int i = 0; i < num; i++) { to = (TableObject) tableList.get(i); //只有记录大于0的表才进行输出 if (to.getRecordnum() >

0) {

FileList.add (to.getBackupfile ())

}

}

FileList.add (entryFileName)

/ / 2. Compress all files and delete temporary files

Try {

FileUtility.zip (fileList, backupFilePath, backupFileName)

FileUtility.delete (fileList, backupFilePath)

} catch (Exception e) {

}

}

/ * *

* check whether the path is legal and throw an exception

* @ param path

* @ return

, /

Public static String checkPath (String path) {

If (! path.matches ("[^ *?"

< >

|] {1,} ") {

} else {

File dir = new File (path)

If (! dir.exists ()) {

}

Return dir.getAbsolutePath () + File.separator

}

}

}

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