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Java in a Nutshell

Previous Chapter 24
The java.io Package

24.16 java.io.File (JDK 1.0)

This class supports a platform-independent definition of file and directory names. It also provides methods to list the files in a directory, to check the existence, readability, writeability, type, size, and modification time of files and directories, to make new directories, to rename files and directories, and to delete files and directories. The constants defined by this class are the platform-dependent directory and path separator characters, available as a String or char.

getName() returns the name of the File with any directory names omitted. getPath() returns the full name of the file, including the directory name. getParent() returns the directory of the File. If the File is an absolute specification, then getAbsolutePath() returns the complete filename. Otherwise, if the File is a relative file specification, it returns the relative filename appended to the current working directory.

isAbsolute() tests whether the File is an absolute specification. exists(), canWrite(), canRead(), isFile(), and isDirectory() perform the obvious tests on the specified File. length() returns the length of the file. lastModified() returns the modification time of the file (which should be used for comparison with other file times only, and not interpreted as any particular time format).

list() returns the name of all entries in a directory that are not rejected by an optional FilenameFilter. mkdir() creates a directory. mkdirs() creates all the directories in a File specification. renameTo() renames a file or directory. delete() deletes a file or directory. Note that there is no method to create a file; that is done with a FileOutputStream.

public class File extends Object implements Serializable {
    // Public Constructors
            public File(String path);
            public File(String path, String name);
            public File(File dir, String name);
    // Constants
            public static final String pathSeparator;
            public static final char pathSeparatorChar;
            public static final String separator;
            public static final char separatorChar;
    // Public Instance Methods
            public boolean canRead();
            public boolean canWrite();
            public boolean delete();
            public boolean equals(Object obj);  // Overrides Object
            public boolean exists();
            public String getAbsolutePath();
        1.1  public String getCanonicalPath() throws IOException;
            public String getName();
            public String getParent();
            public String getPath();
            public int hashCode();  // Overrides Object
            public native boolean isAbsolute();
            public boolean isDirectory();
            public boolean isFile();
            public long lastModified();
            public long length();
            public String[] list();
            public String[] list(FilenameFilter filter);
            public boolean mkdir();
            public boolean mkdirs();
            public boolean renameTo(File dest);
            public String toString();  // Overrides Object

Passed To:

File(), File.renameTo(), FileInputStream(), FilenameFilter.accept(), FileOutputStream(), FileReader(), FileWriter(), RandomAccessFile(), ZipFile()

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