Java class separate file

DVers, please explain if I can edit this question to make it more appropriate for the site. I could not find an answer from searching the internet nor stackoverflow.

Tunaki thanks for the link — Szmagpie. I was going to write a full answer, but I figured this should help docs. Do they have t be n separate classes? Add a comment. Active Oldest Votes. Here's why: package foo. As a result you have to do this to keep them in the same file: package foo. Besides, it's easier to manage small source files. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually.

Linked Building which is a different package. I don't know if it's a typo in the question or what. We'll have to wait for an update. I have edited the compiler error. Yes both class have the same package, com. Show 2 more comments. Active Oldest Votes. Isaac Truett Isaac Truett 8, 1 1 gold badge 27 27 silver badges 48 48 bronze badges. Add a comment. Seems like Person.

Building needs Person's class file for compiling instead of. You must import the class you're referencing: import Person;. I disagree - it looks like he's using the same package name com. Liv Liv 5, 1 1 gold badge 20 20 silver badges 29 29 bronze badges. Re-edited my question, looks exactly as you state but still cant compile. Tried this but failed javac -d.. Sign up or log in Sign up using Google. Sign up using Facebook.

For a given abstract pathname f it is guaranteed that new File f. This relationship typically does not hold, however, when a file: URI that is created in a virtual machine on one operating system is converted into an abstract pathname in a virtual machine on a different operating system.

Parameters: uri - An absolute, hierarchical URI with a scheme equal to "file" , a non-empty path component, and undefined authority, query, and fragment components Throws: NullPointerException - If uri is null IllegalArgumentException - If the preconditions on the parameter do not hold Since: 1.

This is just the last name in the pathname's name sequence. If the pathname's name sequence is empty, then the empty string is returned. Returns: The name of the file or directory denoted by this abstract pathname, or the empty string if this pathname's name sequence is empty getParent public String getParent Returns the pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.

The parent of an abstract pathname consists of the pathname's prefix, if any, and each name in the pathname's name sequence except for the last. If the name sequence is empty then the pathname does not name a parent directory. Returns: The pathname string of the parent directory named by this abstract pathname, or null if this pathname does not name a parent getParentFile public File getParentFile Returns the abstract pathname of this abstract pathname's parent, or null if this pathname does not name a parent directory.

Returns: The abstract pathname of the parent directory named by this abstract pathname, or null if this pathname does not name a parent Since: 1. The resulting string uses the default name-separator character to separate the names in the name sequence. Returns: The string form of this abstract pathname isAbsolute public boolean isAbsolute Tests whether this abstract pathname is absolute. The definition of absolute pathname is system dependent.

Returns: true if this abstract pathname is absolute, false otherwise getAbsolutePath public String getAbsolutePath Returns the absolute pathname string of this abstract pathname. If this abstract pathname is already absolute, then the pathname string is simply returned as if by the getPath method. If this abstract pathname is the empty abstract pathname then the pathname string of the current user directory, which is named by the system property user. Otherwise this pathname is resolved in a system-dependent way.

On UNIX systems, a relative pathname is made absolute by resolving it against the current user directory. On Microsoft Windows systems, a relative pathname is made absolute by resolving it against the current directory of the drive named by the pathname, if any; if not, it is resolved against the current user directory. Returns: The absolute pathname string denoting the same file or directory as this abstract pathname Throws: SecurityException - If a required system property value cannot be accessed.

Equivalent to new File this. Returns: The absolute abstract pathname denoting the same file or directory as this abstract pathname Throws: SecurityException - If a required system property value cannot be accessed.

Since: 1. A canonical pathname is both absolute and unique. The precise definition of canonical form is system-dependent. This method first converts this pathname to absolute form if necessary, as if by invoking the getAbsolutePath method, and then maps it to its unique form in a system-dependent way.

This typically involves removing redundant names such as ". Every pathname that denotes an existing file or directory has a unique canonical form. Every pathname that denotes a nonexistent file or directory also has a unique canonical form.

The canonical form of the pathname of a nonexistent file or directory may be different from the canonical form of the same pathname after the file or directory is created. Similarly, the canonical form of the pathname of an existing file or directory may be different from the canonical form of the same pathname after the file or directory is deleted.

FileDescriptor method denies read access to the file Since: 1. Converts this abstract pathname into a file: URL. The exact form of the URL is system-dependent. If it can be determined that the file denoted by this abstract pathname is a directory, then the resulting URL will end with a slash.

The exact form of the URI is system-dependent. If it can be determined that the file denoted by this abstract pathname is a directory, then the resulting URI will end with a slash. For a given abstract pathname f , it is guaranteed that new File f. Due to the system-dependent nature of abstract pathnames, however, this relationship typically does not hold when a file: URI that is created in a virtual machine on one operating system is converted into an abstract pathname in a virtual machine on a different operating system.

The authority component is undefined, meaning that it is represented as null. The Path class defines the toUri method to encode the server name in the authority component of the resulting URI. The toPath method may be used to obtain a Path representing this abstract pathname. Returns: An absolute, hierarchical URI with a scheme equal to "file" , a path representing this abstract pathname, and undefined authority, query, and fragment components Throws: SecurityException - If a required system property value cannot be accessed.

Returns: true if and only if the file specified by this abstract pathname exists and can be read by the application; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager. String method denies read access to the file canWrite public boolean canWrite Tests whether the application can modify the file denoted by this abstract pathname. Returns: true if and only if the file system actually contains a file denoted by this abstract pathname and the application is allowed to write to the file; false otherwise.

String method denies write access to the file exists public boolean exists Tests whether the file or directory denoted by this abstract pathname exists. Returns: true if and only if the file or directory denoted by this abstract pathname exists; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager. String method denies read access to the file or directory isDirectory public boolean isDirectory Tests whether the file denoted by this abstract pathname is a directory.

Returns: true if and only if the file denoted by this abstract pathname exists and is a directory; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager. String method denies read access to the file isFile public boolean isFile Tests whether the file denoted by this abstract pathname is a normal file.

A file is normal if it is not a directory and, in addition, satisfies other system-dependent criteria. Any non-directory file created by a Java application is guaranteed to be a normal file. Returns: true if and only if the file denoted by this abstract pathname exists and is a normal file; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager.

String method denies read access to the file isHidden public boolean isHidden Tests whether the file named by this abstract pathname is a hidden file. The exact definition of hidden is system-dependent.

On UNIX systems, a file is considered to be hidden if its name begins with a period character '. On Microsoft Windows systems, a file is considered to be hidden if it has been marked as such in the filesystem. Returns: true if and only if the file denoted by this abstract pathname is hidden according to the conventions of the underlying platform Throws: SecurityException - If a security manager exists and its SecurityManager.

String method denies read access to the file Since: 1. String method denies read access to the file length public long length Returns the length of the file denoted by this abstract pathname.

The return value is unspecified if this pathname denotes a directory. Returns: The length, in bytes, of the file denoted by this abstract pathname, or 0L if the file does not exist. Some operating systems may return 0L for pathnames denoting system-dependent entities such as devices or pipes. String method denies read access to the file createNewFile public boolean createNewFile throws IOException Atomically creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist.

The check for the existence of the file and the creation of the file if it does not exist are a single operation that is atomic with respect to all other filesystem activities that might affect the file.

Note: this method should not be used for file-locking, as the resulting protocol cannot be made to work reliably. The FileLock facility should be used instead. String method denies write access to the file Since: 1. If this pathname denotes a directory, then the directory must be empty in order to be deleted.

Note that the Files class defines the delete method to throw an IOException when a file cannot be deleted. This is useful for error reporting and to diagnose why a file cannot be deleted.

Returns: true if and only if the file or directory is successfully deleted; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager. String method denies delete access to the file deleteOnExit public void deleteOnExit Requests that the file or directory denoted by this abstract pathname be deleted when the virtual machine terminates.

Files or directories are deleted in the reverse order that they are registered. Invoking this method to delete a file or directory that is already registered for deletion has no effect. Deletion will be attempted only for normal termination of the virtual machine, as defined by the Java Language Specification.

Once deletion has been requested, it is not possible to cancel the request. This method should therefore be used with care. String method denies delete access to the file Since: 1. If this abstract pathname does not denote a directory, then this method returns null.

Otherwise an array of strings is returned, one for each file or directory in the directory. Names denoting the directory itself and the directory's parent directory are not included in the result. Each string is a file name rather than a complete path. There is no guarantee that the name strings in the resulting array will appear in any specific order; they are not, in particular, guaranteed to appear in alphabetical order. Note that the Files class defines the newDirectoryStream method to open a directory and iterate over the names of the files in the directory.

This may use less resources when working with very large directories, and may be more responsive when working with remote directories. Returns: An array of strings naming the files and directories in the directory denoted by this abstract pathname.

The array will be empty if the directory is empty. The behavior of this method is the same as that of the list method, except that the strings in the returned array must satisfy the filter. If the given filter is null then all names are accepted. Otherwise, a name satisfies the filter if and only if the value true results when the FilenameFilter. Parameters: filter - A filename filter Returns: An array of strings naming the files and directories in the directory denoted by this abstract pathname that were accepted by the given filter.

The array will be empty if the directory is empty or if no names were accepted by the filter. Otherwise an array of File objects is returned, one for each file or directory in the directory. Pathnames denoting the directory itself and the directory's parent directory are not included in the result. Each resulting abstract pathname is constructed from this abstract pathname using the File File, String constructor. Therefore if this pathname is absolute then each resulting pathname is absolute; if this pathname is relative then each resulting pathname will be relative to the same directory.

This may use less resources when working with very large directories. Returns: An array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname. The behavior of this method is the same as that of the listFiles method, except that the pathnames in the returned array must satisfy the filter.

If the given filter is null then all pathnames are accepted. Otherwise, a pathname satisfies the filter if and only if the value true results when the FilenameFilter.

Parameters: filter - A filename filter Returns: An array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname. Otherwise, a pathname satisfies the filter if and only if the value true results when the FileFilter.

Parameters: filter - A file filter Returns: An array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname. Filter mkdir public boolean mkdir Creates the directory named by this abstract pathname. Returns: true if and only if the directory was created; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager. String method does not permit the named directory to be created mkdirs public boolean mkdirs Creates the directory named by this abstract pathname, including any necessary but nonexistent parent directories.

Note that if this operation fails it may have succeeded in creating some of the necessary parent directories. Returns: true if and only if the directory was created, along with all necessary parent directories; false otherwise Throws: SecurityException - If a security manager exists and its SecurityManager.

String method does not permit verification of the existence of the named directory and all necessary parent directories; or if the SecurityManager.