Class SafeFileOutputStream
- java.lang.Object
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- java.io.OutputStream
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- com.inductiveautomation.ignition.common.util.SafeFileOutputStream
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- All Implemented Interfaces:
java.io.Closeable
,java.io.Flushable
,java.lang.AutoCloseable
public class SafeFileOutputStream extends java.io.OutputStream
A FileOutputStream that implements a two-stage write process, and additionaly copies any existing file to a backup location. This ensures that no matter what (software or hardware failures), there is always a valid (non-corrupt) copy of the destination file. More formally, the logic is as follows.
- As write() is called on the SafeFileOutputStream instance, information is written to a temporary file, obtained by File.createTempFile().
- When close() is called, the destination file (if it exists), is renamed to the backup file
- Then the temp file is renamed to the destination file
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Constructor Summary
Constructors Constructor Description SafeFileOutputStream(java.io.File destinationFile, java.io.File backupFile)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
close()
void
flush()
void
write(byte[] b)
void
write(byte[] b, int off, int len)
void
write(int b)
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Method Detail
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close
public void close() throws java.io.IOException
- Specified by:
close
in interfacejava.lang.AutoCloseable
- Specified by:
close
in interfacejava.io.Closeable
- Overrides:
close
in classjava.io.OutputStream
- Throws:
java.io.IOException
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flush
public void flush() throws java.io.IOException
- Specified by:
flush
in interfacejava.io.Flushable
- Overrides:
flush
in classjava.io.OutputStream
- Throws:
java.io.IOException
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write
public void write(byte[] b, int off, int len) throws java.io.IOException
- Overrides:
write
in classjava.io.OutputStream
- Throws:
java.io.IOException
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write
public void write(byte[] b) throws java.io.IOException
- Overrides:
write
in classjava.io.OutputStream
- Throws:
java.io.IOException
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write
public void write(int b) throws java.io.IOException
- Specified by:
write
in classjava.io.OutputStream
- Throws:
java.io.IOException
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