com.indeed.util.io

Class Files

java.lang.Object

com.indeed.util.io.Files

public class Files
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
static void	appendToTextFile(java.lang.String[] lines, java.lang.String file)
static java.lang.String	buildPath(java.lang.String... parts)
static long	computeFileChecksum(java.io.File file, java.util.zip.Checksum checksum)
static boolean	delete(java.lang.String file) Deletes file or recursively deletes a directory NOTE: this returns true if the file was actually deleted, and false for 2 cases: 1.
static boolean	deleteOrDie(java.lang.String file) Deletes file or recursively deletes a directory
static java.io.BufferedReader	getBufferedReaderForUtf8(java.lang.String file)
static java.lang.String	getCanonicalDirectoryName(java.lang.String path) Gets the directory name of the canonical path -- the last element in the result of getCanonicalPath(String).
static java.lang.String	getCanonicalPath(java.lang.String path) Use this function instead of File.getCanonicalPath(), as that method can fail during symlink changes, and this method will retry up to 3 times with a short delay.
static java.lang.String	getFileHash(java.lang.String file, java.lang.String algorithm)
static java.lang.String	getTempDirectory(java.lang.String prefix, java.lang.String suffix)
static java.lang.String	getTempDirectory(java.lang.String prefix, java.lang.String suffix, java.io.File directory)
static java.lang.String	getTempDirectory(java.lang.String prefix, java.lang.String suffix, java.lang.String directory)
static byte[]	loadFileAsByteArray(java.lang.String file)
static java.io.Writer	newBufferedUTF8FileWriter(java.io.File file) Use this instead of FileWriter because you cannot specify the character encoding with that.
static java.io.Writer	newBufferedUTF8FileWriter(java.lang.String file) Use this instead of FileWriter because you cannot specify the character encoding with that.
static java.util.List<java.lang.String>	readCommentedTextFile(java.lang.String file) Reads all the lines in the given file, truncating everything that happens after # (including the #)
static float[]	readFloatsFromTextFile(java.lang.String file)
static int[]	readIntsFromTextFile(java.lang.String file)
static java.lang.Object	readObjectFromClasspathDir(java.lang.String file) Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where: clazz is Object.class printException is false
static <T> T	readObjectFromClasspathDir(java.lang.String file, java.lang.Class<T> clazz, boolean printException)
static java.lang.Object	readObjectFromFile(java.lang.String file) Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where: clazz is Object.class printException is false
static java.lang.Object	readObjectFromFile(java.lang.String file, boolean printException) Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where: clazz is Object.class
static <T> T	readObjectFromFile(java.lang.String file, java.lang.Class<T> clazz) Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where: printException is false
static <T> T	readObjectFromFile(java.lang.String file, java.lang.Class<T> clazz, boolean printException) Reads an object of type T from file.
static java.lang.String	readStreamAsString(java.io.InputStream in)
static java.lang.String	readStreamAsString(java.io.InputStream in, int bufferSize)
static java.lang.String[]	readTextFile(java.lang.String file)
static java.lang.String[]	readTextFileOrDie(java.lang.String file)
static java.lang.String	toHex(byte[] bytes) Converts a byte array to a hex string.
static boolean	writeObjectIfChanged(java.lang.Object obj, java.lang.String filepath) Deprecated. use writeObjectIfChangedOrDie(Object, String, org.apache.log4j.Logger) instead
static boolean	writeObjectIfChangedOrDie(java.lang.Object obj, java.lang.String file) Writes an object to a file only if it is different from the current contents of the file, or if the file does not exist.
static boolean	writeObjectIfChangedOrDie(java.lang.Object obj, java.lang.String file, org.apache.log4j.Logger log) Writes an object to a file only if it is different from the current contents of the file, or if the file does not exist.
static boolean	writeObjectToFile(java.lang.Object obj, java.lang.String file) Deprecated. use writeObjectToFileOrDie(Object, String, org.apache.log4j.Logger) instead
static void	writeObjectToFileOrDie(java.lang.Object obj, java.lang.String file) Serializes an object to a file, throws an exception if it fails
static void	writeObjectToFileOrDie(java.lang.Object obj, java.lang.String file, org.apache.log4j.Logger log) Serializes an object to a file, throws an exception if it fails
static void	writeToTextFile(java.lang.String[] lines, java.lang.String file) Deprecated.
static void	writeToTextFileOrDie(java.lang.String[] lines, java.lang.String file)

Methods inherited from class java.lang.Object

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

Method Detail

buildPath

public static java.lang.String buildPath(java.lang.String... parts)

writeObjectToFileOrDie

public static void writeObjectToFileOrDie(@Nonnull
                                          java.lang.Object obj,
                                          @Nonnull
                                          java.lang.String file)
                                   throws java.io.IOException

Serializes an object to a file, throws an exception if it fails

Parameters:

obj - object to write to a file

file - path to save the object to

Throws:

java.io.IOException - if the existing file could not be erased, or the file could not be written, flushed, synced, or closed

writeObjectToFileOrDie

public static void writeObjectToFileOrDie(@Nonnull
                                          java.lang.Object obj,
                                          @Nonnull
                                          java.lang.String file,
                                          @Nonnull
                                          org.apache.log4j.Logger log)
                                   throws java.io.IOException

Serializes an object to a file, throws an exception if it fails

Parameters:

obj - object to write to a file

file - path to save the object to

log - logger to use

Throws:

java.io.IOException - if the existing file could not be erased, or the file could not be written, flushed, synced, or closed

writeObjectIfChangedOrDie

public static boolean writeObjectIfChangedOrDie(@Nonnull
                                                java.lang.Object obj,
                                                @Nonnull
                                                java.lang.String file)
                                         throws java.io.IOException

Writes an object to a file only if it is different from the current contents of the file, or if the file does not exist. Note that you must have enough heap to contain the entire contents of the object graph.

Parameters:

obj - object to write to a file

file - path to save the object to

Returns:

true if the file was actually written, false if the file was unchanged

Throws:

java.io.IOException - if the existing file could not be read for comparison, if the existing file could not be erased, or if the new file could not be written, flushed, synced, or closed

writeObjectIfChangedOrDie

public static boolean writeObjectIfChangedOrDie(@Nonnull
                                                java.lang.Object obj,
                                                @Nonnull
                                                java.lang.String file,
                                                @Nonnull
                                                org.apache.log4j.Logger log)
                                         throws java.io.IOException

Writes an object to a file only if it is different from the current contents of the file, or if the file does not exist. Note that you must have enough heap to contain the entire contents of the object graph.

Parameters:

obj - object to write to a file

file - path to save the object to

log - logger to use

Returns:

true if the file was actually written, false if the file was unchanged

Throws:

java.io.IOException - if the existing file could not be read for comparison, if the existing file could not be erased, or if the new file could not be written, flushed, synced, or closed

computeFileChecksum

public static long computeFileChecksum(@Nonnull
                                       java.io.File file,
                                       @Nonnull
                                       java.util.zip.Checksum checksum)
                                throws java.io.IOException

Throws:

java.io.IOException

writeObjectToFile

@Deprecated
public static boolean writeObjectToFile(java.lang.Object obj,
                                                    java.lang.String file)

Deprecated. use writeObjectToFileOrDie(Object, String, org.apache.log4j.Logger) instead

Writes an object to a file.

Returns:

true if the file was successfully written, false otherwise

writeObjectIfChanged

@Deprecated
public static boolean writeObjectIfChanged(java.lang.Object obj,
                                                       java.lang.String filepath)

Deprecated. use writeObjectIfChangedOrDie(Object, String, org.apache.log4j.Logger) instead

Writes an object to a file only if it is different from the current contents of the file, or if the file does not exist. Note that you must have enough heap to contain the entire contents of the object graph.

Returns:

true if the file was actually written, false otherwise

readObjectFromFile

public static <T> T readObjectFromFile(java.lang.String file,
                                       java.lang.Class<T> clazz,
                                       boolean printException)

Reads an object of type T from file.

Type Parameters:

T - the return type

Parameters:

file - file from which the object should be read

clazz - non-null Class object for T

printException - whether or not any stacktraces should be printed

Returns:

possibly null object of type T.

readObjectFromClasspathDir

public static java.lang.Object readObjectFromClasspathDir(java.lang.String file)

Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where:

• clazz is Object.class
• printException is false

readObjectFromClasspathDir

public static <T> T readObjectFromClasspathDir(java.lang.String file,
                                               java.lang.Class<T> clazz,
                                               boolean printException)

readObjectFromFile

public static <T> T readObjectFromFile(java.lang.String file,
                                       java.lang.Class<T> clazz)

Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where:

• printException is false

readObjectFromFile

public static java.lang.Object readObjectFromFile(java.lang.String file,
                                                  boolean printException)

Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where:

• clazz is Object.class

readObjectFromFile

public static java.lang.Object readObjectFromFile(java.lang.String file)

Convenience for readObjectFromFile(String file, Class clazz, boolean printException) where:

• clazz is Object.class
• printException is false

readTextFile

public static java.lang.String[] readTextFile(java.lang.String file)

readTextFileOrDie

public static java.lang.String[] readTextFileOrDie(java.lang.String file)
                                            throws java.io.IOException

Throws:

java.io.IOException

readCommentedTextFile

public static java.util.List<java.lang.String> readCommentedTextFile(java.lang.String file)
                                                              throws java.io.IOException

Reads all the lines in the given file, truncating everything that happens after # (including the #)

Parameters:

file -

Returns:

a List of the lines in the file in the order they appear (whitespace trimmed)

Throws:

java.io.IOException

readIntsFromTextFile

public static int[] readIntsFromTextFile(java.lang.String file)

readFloatsFromTextFile

public static float[] readFloatsFromTextFile(java.lang.String file)

writeToTextFile

@Deprecated
public static void writeToTextFile(java.lang.String[] lines,
                                               java.lang.String file)

Deprecated.

writeToTextFileOrDie

public static void writeToTextFileOrDie(@Nonnull
                                        java.lang.String[] lines,
                                        @Nonnull
                                        java.lang.String file)
                                 throws java.io.IOException

Throws:

java.io.IOException

appendToTextFile

public static void appendToTextFile(java.lang.String[] lines,
                                    java.lang.String file)

getTempDirectory

public static java.lang.String getTempDirectory(java.lang.String prefix,
                                                java.lang.String suffix)
                                         throws java.io.IOException

Throws:

java.io.IOException

getTempDirectory

public static java.lang.String getTempDirectory(java.lang.String prefix,
                                                java.lang.String suffix,
                                                java.lang.String directory)
                                         throws java.io.IOException

Throws:

java.io.IOException

getTempDirectory

public static java.lang.String getTempDirectory(java.lang.String prefix,
                                                java.lang.String suffix,
                                                java.io.File directory)
                                         throws java.io.IOException

Throws:

java.io.IOException

delete

public static boolean delete(java.lang.String file)

Deletes file or recursively deletes a directory NOTE: this returns true if the file was actually deleted, and false for 2 cases: 1. file did not exist to start with 2. File.delete() failed at some point for some reason use deleteOrDie(String) instead if you want a clearer distinction between the 'falsy' responses

Parameters:

file - path to erase

Returns:

true if all deletions were successful. If a deletion fails, the method stops attempting to delete and returns false

deleteOrDie

public static boolean deleteOrDie(@Nonnull
                                  java.lang.String file)
                           throws java.io.IOException

Deletes file or recursively deletes a directory

Parameters:

file - path to erase

Returns:

true if all deletions were successful, false if file did not exist

Throws:

java.io.IOException - if deletion fails and the file still exists at the end

getCanonicalPath

public static java.lang.String getCanonicalPath(java.lang.String path)

Use this function instead of File.getCanonicalPath(), as that method can fail during symlink changes, and this method will retry up to 3 times with a short delay. Returns null if unsuccessful after retrying.

Parameters:

path - path to canonicalize

Returns:

the canonical pathname, or null if unsuccessful

getCanonicalDirectoryName

public static java.lang.String getCanonicalDirectoryName(java.lang.String path)

Gets the directory name of the canonical path -- the last element in the result of getCanonicalPath(String).

Parameters:

path - path to canonicalize

Returns:

canonical directory name

loadFileAsByteArray

public static byte[] loadFileAsByteArray(java.lang.String file)
                                  throws java.io.IOException

Throws:

java.io.IOException

getFileHash

public static java.lang.String getFileHash(java.lang.String file,
                                           java.lang.String algorithm)
                                    throws java.io.IOException,
                                           java.security.NoSuchAlgorithmException

Throws:

java.io.IOException

java.security.NoSuchAlgorithmException

toHex

@Nonnull
public static java.lang.String toHex(@Nonnull
                                              byte[] bytes)

Converts a byte array to a hex string. The String returned will be of length exactly bytes.length * 2.

getBufferedReaderForUtf8

public static java.io.BufferedReader getBufferedReaderForUtf8(java.lang.String file)
                                                       throws java.io.FileNotFoundException

Throws:

java.io.FileNotFoundException

readStreamAsString

public static java.lang.String readStreamAsString(java.io.InputStream in)
                                           throws java.io.IOException

Throws:

java.io.IOException

readStreamAsString

public static java.lang.String readStreamAsString(java.io.InputStream in,
                                                  int bufferSize)
                                           throws java.io.IOException

Throws:

java.io.IOException

newBufferedUTF8FileWriter

public static java.io.Writer newBufferedUTF8FileWriter(java.lang.String file)
                                                throws java.io.UnsupportedEncodingException,
                                                       java.io.FileNotFoundException

Use this instead of FileWriter because you cannot specify the character encoding with that.

Throws:

java.io.UnsupportedEncodingException

java.io.FileNotFoundException

newBufferedUTF8FileWriter

public static java.io.Writer newBufferedUTF8FileWriter(java.io.File file)
                                                throws java.io.UnsupportedEncodingException,
                                                       java.io.FileNotFoundException

Use this instead of FileWriter because you cannot specify the character encoding with that.

Throws:

java.io.UnsupportedEncodingException

java.io.FileNotFoundException