org.vishia.util

Class FileAppend

java.lang.Object

org.vishia.util.FileAppend

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.Appendable, java.lang.AutoCloseable

public class FileAppend
extends java.lang.Object
implements java.lang.Appendable, java.io.Closeable, java.io.Flushable

This class is a alternative to java.io.FileWriter. It based on java.util.OutputStreamWriter, adequate to java.io.FileWriter. But in opposite to that,

• The instance of this class will be preserved also if the file is closed, respectively the instance can be created static, without opened file. It is because usage in fast realtime systems in C via Java2C-translator. The implementation in C is written without any dynamically memory.
• On open() no exceptions are thrown, a boolean return value is used.
• Also append(CharSequence) is exception-free similar as in System.out ( PrintStream ). Advantage for the user: exchange both without effort of try-catch.
• On open(String, boolean) and open(String, String, boolean) a path with environment variables or starting with "/tmp/" or "~" can be used.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FileAppend.Wr

Field Summary

Fields

Modifier and Type	Field and Description
private int	error
static int	kFileNotFound
static int	kFileOpenError
static int	kWriteError
java.lang.String	sError
static java.lang.String	sVersion Version, history and license.
protected FileAppend.Wr	writer The OutputStreamWriter can't be used as superclass, because the file is able to open only with calling constructor.

Constructor Summary

Constructors

Constructor and Description
FileAppend()

Method Summary

Modifier and Type	Method and Description
java.lang.Appendable	append(char c)
FileAppend.Wr	append(java.lang.CharSequence text) In opposite to the original Writer.append(CharSequence) this operation does not throw.
java.lang.Appendable	append(java.lang.CharSequence csq, int start, int end)
void	close()
void	finalize() Important: On garbage at least close() is called here to prevent resource leaks.
void	flush()
int	getError()
boolean	isOpen()
int	open(java.lang.String filePath, boolean append) opens a file to write.
int	open(java.lang.String fileName, java.lang.String sEncoding, boolean append) opens a file to write.
void	write(java.lang.String text)

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

sVersion

public static final java.lang.String sVersion

Version, history and license. Changes:

• 2022-01-17 Hartmut new: open(String, String, boolean) with specific encoding.
• 2011 Hartmut: created

Copyright/Copyleft: For this source the LGPL Lesser General Public License, published by the Free Software Foundation is valid. It means:

1. You can use this source without any restriction for any desired purpose.
2. You can redistribute copies of this source to everybody.
3. Every user of this source, also the user of redistribute copies with or without payment, must accept this license for further using.
4. But the LPGL ist not appropriate for a whole software product, if this source is only a part of them. It means, the user must publish this part of source, but don't need to publish the whole source of the own product.
5. You can study and modify (improve) this source for own using or for redistribution, but you have to license the modified sources likewise under this LGPL Lesser General Public License. You mustn't delete this Copyright/Copyleft inscription in this source file.

If you are intent to use this sources without publishing its usage, you can get a second license subscribing a special contract with the author.

See Also:

Constant Field Values

writer

protected FileAppend.Wr writer

The OutputStreamWriter can't be used as superclass, because the file is able to open only with calling constructor. Thats why all methods of OutputStreamWriter have to be wrapped here.

kFileNotFound

public static final int kFileNotFound

See Also:

Constant Field Values

kFileOpenError

public static final int kFileOpenError

See Also:

Constant Field Values

kWriteError

public static final int kWriteError

See Also:

Constant Field Values

sError

public java.lang.String sError

error

private int error

Constructor Detail

FileAppend

public FileAppend()

Method Detail

open

public int open(java.lang.String filePath,
                boolean append)

opens a file to write. Hint: You must not forget close() on end of usage.

Parameters:

filePath - Path to the file. To separate folder, a slash '/' should be used. But a backslash is also accepted. An absolute path should be start either with slash or with a one-char drive specifier, following by ':/'. The filePath can also contain environment variables due to Arguments.replaceEnv(String). and also can start with /tmp/ or ~ for home, see FileFunctions.absolutePath(String, java.io.File).

append - If the file exists, the content written than is appended.

Returns:

0 if the file is opened, -1 if the file is not found, -2 on other conditions.

open

public int open(java.lang.String fileName,
                java.lang.String sEncoding,
                boolean append)

opens a file to write. Hint: You must not forget close() on end of usage.

Parameters:

filePath - Path to the file. To separate folder, a slash '/' should be used. But a backslash is also accepted. An absolute path should be start either with slash or with a one-char drive specifier, following by ':/'. The filePath can also contain environment variables due to Arguments.replaceEnv(String) and also can start with /tmp/ or ~ for home, see FileFunctions.absolutePath(String, java.io.File).

sEncoding - character encoding for the binary file, "UTF-8" etc. see OutputStreamWriter.OutputStreamWriter(java.io.OutputStream, String)

append - If the file exists, the content written than is appended.

Returns:

0 if the file is opened, -1 if the file is not found, -2 on other conditions.

isOpen

public boolean isOpen()

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

write

public void write(java.lang.String text)
           throws java.io.IOException

Throws:

java.io.IOException

append

public FileAppend.Wr append(java.lang.CharSequence text)

In opposite to the original Writer.append(CharSequence) this operation does not throw. Instead it does nothing on error, but the internal error is set to -3, returned by getError(). The original throw is catched here. It is similar System.out.append(), the user does not need additional try, An error is able to check for the whole output.

Specified by:

append in interface java.lang.Appendable

flush

public void flush()
           throws java.io.IOException

Specified by:

flush in interface java.io.Flushable

Throws:

java.io.IOException

finalize

public void finalize()

Important: On garbage at least close() is called here to prevent resource leaks.

Overrides:

finalize in class java.lang.Object

getError

public int getError()

append

public java.lang.Appendable append(java.lang.CharSequence csq,
                                   int start,
                                   int end)
                            throws java.io.IOException

Specified by:

append in interface java.lang.Appendable

Throws:

java.io.IOException

append

public java.lang.Appendable append(char c)
                            throws java.io.IOException

Specified by:

append in interface java.lang.Appendable

Throws:

java.io.IOException