android 记得用mkdirs不要用mkdir

反正加s就对了，mkdir不能创建多个目录

 

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android的文件操作要有权限：

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

<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

Environment.getExternalStorageState().equals(
        android.os.Environment.MEDIA_MOUNTED);

Environment.getExternalStorageState().equals( android.os.Environment.MEDIA_MOUNTED);

 

2、获得sd卡根目录：

File skRoot = Environment.getExternalStorageDirectory();

File skRoot = Environment.getExternalStorageDirectory();

 

私有目录下的文件操作：

1、获得私有根目录：

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

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

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

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

String parentPath = File.getParent();

String parentPath = File.getParent();

 

c、获得文件或文件夹的名称：

String Name = File.getName();

String Name = File.getName();

 

2、建立文件或文件夹

File.mkDir(); //建立文件夹
File.createNewFile();//建立文件

File.mkDir(); //建立文件夹 File.createNewFile();//建立文件

 

3、判断是文件或文件夹

File.isDirectory()

File.isDirectory()

 

4、列出文件夹下的所有文件和文件夹名

File[] files = File.listFiles();

File[] files = File.listFiles();

 

5、修改文件夹和文件名

File.renameTo(dest);

File.renameTo(dest);

 

6、删除文件夹或文件

File.delete();

File.delete();

 

 

 

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;
    }
}

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。

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());

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。