android的文件操作。（未整理完成）

原文地址：/article/9075535.html
android的文件操作要有权限：

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<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

SD卡下的文件操作：
1、判断SD卡是否插入

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Environment.getExternalStorageState().equals(

android.os.Environment.MEDIA_MOUNTED);

2、获得sd卡根目录：

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File skRoot = Environment.getExternalStorageDirectory();

私有目录下的文件操作：
1、获得私有根目录：

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File fileRoot = Context.getFilesDir()+"//";

还未整理

文件夹或文件夹操作：
1、确定或获得文件夹和文件路径
a、获得文件或文件夹的绝对路径和相对路径。区别

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String path = File.getPath();//相对

String path = File.getAbsoultePath();//绝对

b 、获得文件或文件夹的父目录

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String parentPath = File.getParent();

c、获得文件或文件夹的名称：

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String Name = File.getName();

2、建立文件或文件夹

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File.mkDir(); //建立文件夹

File.createNewFile();//建立文件

3、判断是文件或文件夹

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File.isDirectory()

4、列出文件夹下的所有文件和文件夹名

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File[] files = File.listFiles();

5、修改文件夹和文件名

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File.renameTo(dest);

6、删除文件夹或文件

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File.delete();

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package otheri.common;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import otheri.io.Input;

import otheri.io.Output;

import android.content.Context;

import android.os.Environment;

public class FileHelper {

private Context context;

private String SDPATH;

private String FILESPATH;

public FileHelper(Context context) {

this.context = context;

SDPATH = Environment.getExternalStorageDirectory().getPath() + "//";

FILESPATH = this.context.getFilesDir().getPath() + "//";

}

/**

* 在SD卡上创建文件

*

* @throws IOException

*/

public File creatSDFile(String fileName) throws IOException {

File file = new File(SDPATH + fileName);

file.createNewFile();

return file;

}

/**

* 删除SD卡上的文件

*

* @param fileName

*/

public boolean delSDFile(String fileName) {

File file = new File(SDPATH + fileName);

if (file == null || !file.exists() || file.isDirectory())

return false;

file.delete();

return true;

}

/**

* 在SD卡上创建目录

*

* @param dirName

*/

public File creatSDDir(String dirName) {

File dir = new File(SDPATH + dirName);

dir.mkdir();

return dir;

}

/**

* 删除SD卡上的目录

*

* @param dirName

*/

public boolean delSDDir(String dirName) {

File dir = new File(SDPATH + dirName);

return delDir(dir);

}

/**

* 修改SD卡上的文件或目录名

*

* @param fileName

*/

public boolean renameSDFile(String oldfileName, String newFileName) {

File oleFile = new File(SDPATH + oldfileName);

File newFile = new File(SDPATH + newFileName);

return oleFile.renameTo(newFile);

}

/**

* 拷贝SD卡上的单个文件

*

* @param path

* @throws IOException

*/

public boolean copySDFileTo(String srcFileName, String destFileName)

throws IOException {

File srcFile = new File(SDPATH + srcFileName);

File destFile = new File(SDPATH + destFileName);

return copyFileTo(srcFile, destFile);

}

/**

* 拷贝SD卡上指定目录的所有文件

*

* @param srcDirName

* @param destDirName

* @return

* @throws IOException

*/

public boolean copySDFilesTo(String srcDirName, String destDirName)

throws IOException {

File srcDir = new File(SDPATH + srcDirName);

File destDir = new File(SDPATH + destDirName);

return copyFilesTo(srcDir, destDir);

}

/**

* 移动SD卡上的单个文件

*

* @param srcFileName

* @param destFileName

* @return

* @throws IOException

*/

public boolean moveSDFileTo(String srcFileName, String destFileName)

throws IOException {

File srcFile = new File(SDPATH + srcFileName);

File destFile = new File(SDPATH + destFileName);

return moveFileTo(srcFile, destFile);

}

/**

* 移动SD卡上的指定目录的所有文件

*

* @param srcDirName

* @param destDirName

* @return

* @throws IOException

*/

public boolean moveSDFilesTo(String srcDirName, String destDirName)

throws IOException {

File srcDir = new File(SDPATH + srcDirName);

File destDir = new File(SDPATH + destDirName);

return moveFilesTo(srcDir, destDir);

}

/*

* 将文件写入sd卡。如:writeSDFile("test.txt");

*/

public Output writeSDFile(String fileName) throws IOException {

File file = new File(SDPATH + fileName);

FileOutputStream fos = new FileOutputStream(file);

return new Output(fos);

}

/*

* 在原有文件上继续写文件。如:appendSDFile("test.txt");

*/

public Output appendSDFile(String fileName) throws IOException {

File file = new File(SDPATH + fileName);

FileOutputStream fos = new FileOutputStream(file, true);

return new Output(fos);

}

/*

* 从SD卡读取文件。如:readSDFile("test.txt");

*/

public Input readSDFile(String fileName) throws IOException {

File file = new File(SDPATH + fileName);

FileInputStream fis = new FileInputStream(file);

return new Input(fis);

}

/**

* 建立私有文件

*

* @param fileName

* @return

* @throws IOException

*/

public File creatDataFile(String fileName) throws IOException {

File file = new File(FILESPATH + fileName);

file.createNewFile();

return file;

}

/**

* 建立私有目录

*

* @param dirName

* @return

*/

public File creatDataDir(String dirName) {

File dir = new File(FILESPATH + dirName);

dir.mkdir();

return dir;

}

/**

* 删除私有文件

*

* @param fileName

* @return

*/

public boolean delDataFile(String fileName) {

File file = new File(FILESPATH + fileName);

return delFile(file);

}

/**

* 删除私有目录

*

* @param dirName

* @return

*/

public boolean delDataDir(String dirName) {

File file = new File(FILESPATH + dirName);

return delDir(file);

}

/**

* 更改私有文件名

*

* @param oldName

* @param newName

* @return

*/

public boolean renameDataFile(String oldName, String newName) {

File oldFile = new File(FILESPATH + oldName);

File newFile = new File(FILESPATH + newName);

return oldFile.renameTo(newFile);

}

/**

* 在私有目录下进行文件复制

*

* @param srcFileName

* ： 包含路径及文件名

* @param destFileName

* @return

* @throws IOException

*/

public boolean copyDataFileTo(String srcFileName, String destFileName)

throws IOException {

File srcFile = new File(FILESPATH + srcFileName);

File destFile = new File(FILESPATH + destFileName);

return copyFileTo(srcFile, destFile);

}

/**

* 复制私有目录里指定目录的所有文件

*

* @param srcDirName

* @param destDirName

* @return

* @throws IOException

*/

public boolean copyDataFilesTo(String srcDirName, String destDirName)

throws IOException {

File srcDir = new File(FILESPATH + srcDirName);

File destDir = new File(FILESPATH + destDirName);

return copyFilesTo(srcDir, destDir);

}

/**

* 移动私有目录下的单个文件

*

* @param srcFileName

* @param destFileName

* @return

* @throws IOException

*/

public boolean moveDataFileTo(String srcFileName, String destFileName)

throws IOException {

File srcFile = new File(FILESPATH + srcFileName);

File destFile = new File(FILESPATH + destFileName);

return moveFileTo(srcFile, destFile);

}

/**

* 移动私有目录下的指定目录下的所有文件

*

* @param srcDirName

* @param destDirName

* @return

* @throws IOException

*/

public boolean moveDataFilesTo(String srcDirName, String destDirName)

throws IOException {

File srcDir = new File(FILESPATH + srcDirName);

File destDir = new File(FILESPATH + destDirName);

return moveFilesTo(srcDir, destDir);

}

/*

* 将文件写入应用私有的files目录。如:writeFile("test.txt");

*/

public Output wirteFile(String fileName) throws IOException {

OutputStream os = context.openFileOutput(fileName,

Context.MODE_WORLD_WRITEABLE);

return new Output(os);

}

/*

* 在原有文件上继续写文件。如:appendFile("test.txt");

*/

public Output appendFile(String fileName) throws IOException {

OutputStream os = context.openFileOutput(fileName, Context.MODE_APPEND);

return new Output(os);

}

/*

* 从应用的私有目录files读取文件。如:readFile("test.txt");

*/

public Input readFile(String fileName) throws IOException {

InputStream is = context.openFileInput(fileName);

return new Input(is);

}

/**********************************************************************************************************/

/*********************************************************************************************************/

*/

/**

* 删除一个文件

*

* @param file

* @return

*/

public boolean delFile(File file) {

if (file.isDirectory())

return false;

return file.delete();

}

/**

* 删除一个目录（可以是非空目录）

*

* @param dir

*/

public boolean delDir(File dir) {

if (dir == null || !dir.exists() || dir.isFile()) {

return false;

}

for (File file : dir.listFiles()) {

if (file.isFile()) {

file.delete();

} else if (file.isDirectory()) {

delDir(file);// 递归

}

}

dir.delete();

return true;

}

/**

* 拷贝一个文件,srcFile源文件，destFile目标文件

*

* @param path

* @throws IOException

*/

public boolean copyFileTo(File srcFile, File destFile) throws IOException {

if (srcFile.isDirectory() || destFile.isDirectory())

return false;// 判断是否是文件

FileInputStream fis = new FileInputStream(srcFile);

FileOutputStream fos = new FileOutputStream(destFile);

int readLen = 0;

byte[] buf = new byte[1024];

while ((readLen = fis.read(buf)) != -1) {

fos.write(buf, 0, readLen);

}

fos.flush();

fos.close();

fis.close();

return true;

}

/**

* 拷贝目录下的所有文件到指定目录

*

* @param srcDir

* @param destDir

* @return

* @throws IOException

*/

public boolean copyFilesTo(File srcDir, File destDir) throws IOException {

if (!srcDir.isDirectory() || !destDir.isDirectory())

return false;// 判断是否是目录

if (!destDir.exists())

return false;// 判断目标目录是否存在

File[] srcFiles = srcDir.listFiles();

for (int i = 0; i < srcFiles.length; i++) {

if (srcFiles[i].isFile()) {

// 获得目标文件

File destFile = new File(destDir.getPath() + "//"

+ srcFiles[i].getName());

copyFileTo(srcFiles[i], destFile);

} else if (srcFiles[i].isDirectory()) {

File theDestDir = new File(destDir.getPath() + "//"

+ srcFiles[i].getName());

copyFilesTo(srcFiles[i], theDestDir);

}

}

return true;

}

/**

* 移动一个文件

*

* @param srcFile

* @param destFile

* @return

* @throws IOException

*/

public boolean moveFileTo(File srcFile, File destFile) throws IOException {

boolean iscopy = copyFileTo(srcFile, destFile);

if (!iscopy)

return false;

delFile(srcFile);

return true;

}

/**

* 移动目录下的所有文件到指定目录

*

* @param srcDir

* @param destDir

* @return

* @throws IOException

*/

public boolean moveFilesTo(File srcDir, File destDir) throws IOException {

if (!srcDir.isDirectory() || !destDir.isDirectory()) {

return false;

}

File[] srcDirFiles = srcDir.listFiles();

for (int i = 0; i < srcDirFiles.length; i++) {

if (srcDirFiles[i].isFile()) {

File oneDestFile = new File(destDir.getPath() + "//"

+ srcDirFiles[i].getName());

moveFileTo(srcDirFiles[i], oneDestFile);

delFile(srcDirFiles[i]);

} else if (srcDirFiles[i].isDirectory()) {

File oneDestFile = new File(destDir.getPath() + "//"

+ srcDirFiles[i].getName());

moveFilesTo(srcDirFiles[i], oneDestFile);

delDir(srcDirFiles[i]);

}

}

return true;

}

}

getPath与getAbsoultePath的区别:
getAbsolutePath()：返回抽象路径名的绝对路径名字符串。

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public static void test1(){

File file1 = new File(".//test1.txt");

File file2 = new File("D://workspace//test//test1.txt");

System.out.println("-----默认相对路径：取得路径不同------");

System.out.println(file1.getPath());

System.out.println(file1.getAbsolutePath());

System.out.println("-----默认绝对路径:取得路径相同------");

System.out.println(file2.getPath());

System.out.println(file2.getAbsolutePath());

}

-----默认相对路径：取得路径不同------

./test1.txt

D:/workspace/test/./test1.txt

-----默认绝对路径:取得路径相同------

D:/workspace/test/test1.txt

D:/workspace/test/test1.txt

----------------------------------------------------

public static void test2() throws Exception{

File file = new File("..//src//test1.txt");

System.out.println(file.getAbsolutePath());

System.out.println(file.getCanonicalPath());

}

D:/workspace/test/../src/test1.txt

D:/workspace/src/test1.txt

--------------------------------------------

public static void test3() throws Exception{

File file = new File("D://Text.txt");

System.out.println(file.getCanonicalPath());

(1),确定D盘下没有Text.txt这个文件，直接执行这段代码，得到的结果是:

D:/Text.txt注意这里试大写的Text.txt

(2)在D盘下建立一个文件，名叫text.txt，再次执行代码，得到结果

D:/text.txt同样的代码得到不同的结果。