Package org.plumelib.util

Class FilesPlume

java.lang.Object
org.plumelib.util.FilesPlume
public final class FilesPlume extends Object
Utility methods that create and manipulate files, directories, streams, readers, and writers.

  • Method Details

    • newFileInputStream

      public static InputStream newFileInputStream(Path path) throws IOException
      Returns an InputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      Returns:
      an InputStream for file
      Throws:
      IOException - if there is trouble reading the file

    • newFileInputStream

      public static InputStream newFileInputStream(File file) throws IOException
      Returns an InputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      Returns:
      an InputStream for file
      Throws:
      IOException - if there is trouble reading the file

    • newFileReader

      public static InputStreamReader newFileReader(String filename) throws FileNotFoundException, IOException
      Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to read
      Returns:
      an InputStream for filename
      Throws:
      IOException - if there is trouble reading the file
      FileNotFoundException - if the file is not found

    • newFileReader

      public static InputStreamReader newFileReader(Path path) throws FileNotFoundException, IOException
      Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      Returns:
      an InputStreamReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileReader

      public static InputStreamReader newFileReader(Path path, @Nullable String charsetName) throws FileNotFoundException, IOException
      Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      charsetName - the name of a Charset to use when reading the file, or null to use UTF-8
      Returns:
      an InputStreamReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileReader

      public static InputStreamReader newFileReader(File file) throws FileNotFoundException, IOException
      Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      Returns:
      an InputStreamReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileReader

      public static InputStreamReader newFileReader(File file, @Nullable String charsetName) throws FileNotFoundException, IOException
      Returns a Reader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      charsetName - the name of a Charset to use when reading the file, or null to use UTF-8
      Returns:
      an InputStreamReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newBufferedFileReader

      public static BufferedReader newBufferedFileReader(String filename) throws FileNotFoundException, IOException
      Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to read
      Returns:
      a BufferedReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newBufferedFileReader

      public static BufferedReader newBufferedFileReader(File file) throws FileNotFoundException, IOException
      Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibility-compressed file to read
      Returns:
      a BufferedReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newBufferedFileReader

      public static BufferedReader newBufferedFileReader(String filename, @Nullable String charsetName) throws FileNotFoundException, IOException
      Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to read
      charsetName - the character set to use when reading the file, or null to use UTF-8
      Returns:
      a BufferedReader for filename
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newBufferedFileReader

      public static BufferedReader newBufferedFileReader(File file, @Nullable String charsetName) throws FileNotFoundException, IOException
      Returns a BufferedReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      charsetName - the character set to use when reading the file, or null to use UTF-8
      Returns:
      a BufferedReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newLineNumberFileReader

      public static LineNumberReader newLineNumberFileReader(String filename) throws FileNotFoundException, IOException
      Returns a LineNumberReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to read
      Returns:
      a LineNumberReader for filename
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newLineNumberFileReader

      public static LineNumberReader newLineNumberFileReader(File file) throws FileNotFoundException, IOException
      Returns a LineNumberReader for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      Returns:
      a LineNumberReader for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileOutputStream

      public static OutputStream newFileOutputStream(Path path) throws IOException
      Returns an OutputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      Returns:
      an OutputStream for file
      Throws:
      IOException - if there is trouble reading the file

    • newFileOutputStream

      public static OutputStream newFileOutputStream(Path path, boolean append) throws IOException
      Returns an OutputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      append - if true, then bytes will be written to the end of the file rather than the beginning
      Returns:
      an OutputStream for file
      Throws:
      IOException - if there is trouble reading the file

    • newFileOutputStream

      public static OutputStream newFileOutputStream(File file) throws IOException
      Returns an OutputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      Returns:
      an OutputStream for file
      Throws:
      IOException - if there is trouble reading the file

    • newFileWriter

      public static OutputStreamWriter newFileWriter(String filename) throws FileNotFoundException, IOException
      Returns a Writer for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to read
      Returns:
      an OutputStream for filename
      Throws:
      IOException - if there is trouble reading the file
      FileNotFoundException - if the file is not found

    • newFileWriter

      public static OutputStreamWriter newFileWriter(Path path) throws FileNotFoundException, IOException
      Returns a Writer for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      Returns:
      an OutputStreamWriter for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileWriter

      public static OutputStreamWriter newFileWriter(Path path, @Nullable String charsetName) throws FileNotFoundException, IOException
      Returns a Writer for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      path - the possibly-compressed file to read
      charsetName - the name of a Charset to use when reading the file, or null to use UTF-8
      Returns:
      an OutputStreamWriter for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileWriter

      public static OutputStreamWriter newFileWriter(File file) throws FileNotFoundException, IOException
      Returns a Writer for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      Returns:
      an OutputStreamWriter for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newFileWriter

      public static OutputStreamWriter newFileWriter(File file, @Nullable String charsetName) throws FileNotFoundException, IOException
      Returns a Writer for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      file - the possibly-compressed file to read
      charsetName - the name of a Charset to use when reading the file, or null to use UTF-8
      Returns:
      an OutputStreamWriter for file
      Throws:
      FileNotFoundException - if the file cannot be found
      IOException - if there is trouble reading the file

    • newBufferedFileWriter

      public static BufferedWriter newBufferedFileWriter(String filename) throws IOException
      Returns a BufferedWriter for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to write
      Returns:
      a BufferedWriter for filename
      Throws:
      IOException - if there is trouble writing the file

    • newBufferedFileWriter

      public static BufferedWriter newBufferedFileWriter(String filename, boolean append) throws IOException
      Returns a BufferedWriter for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to write
      append - if true, the resulting BufferedWriter appends to the end of the file instead of the beginning
      Returns:
      a BufferedWriter for filename
      Throws:
      IOException - if there is trouble writing the file

    • newBufferedFileOutputStream

      public static BufferedOutputStream newBufferedFileOutputStream(String filename, boolean append) throws IOException
      Returns a BufferedOutputStream for the file, accounting for the possibility that the file is compressed. (A file whose name ends with ".gz" is treated as compressed.)

      Warning: The "gzip" program writes and reads files containing concatenated gzip files. As of Java 1.4, Java reads just the first one: it silently discards all characters (including gzipped files) after the first gzipped file.

      Parameters:
      filename - the possibly-compressed file to write
      append - if true, the resulting BufferedOutputStream appends to the end of the file instead of the beginning
      Returns:
      a BufferedOutputStream for filename
      Throws:
      IOException - if there is trouble writing the file

    • countLines

      public static long countLines(String filename) throws IOException
      Count the number of lines in the specified file.
      Parameters:
      filename - file whose size to count
      Returns:
      number of lines in filename
      Throws:
      IOException - if there is trouble reading the file

    • inferLineSeparator

      public static String inferLineSeparator(String filename) throws IOException
      Tries to infer the line separator used in a file.
      Parameters:
      filename - the file to infer a line separator from
      Returns:
      the inferred line separator used in filename
      Throws:
      IOException - if there is trouble reading the file

    • inferLineSeparator

      public static String inferLineSeparator(File file) throws IOException
      Tries to infer the line separator used in a file.
      Parameters:
      file - the file to infer a line separator from
      Returns:
      the inferred line separator used in filename
      Throws:
      IOException - if there is trouble reading the file

    • equalFiles

      @Pure public static boolean equalFiles(String file1, String file2)
      Returns true iff files have the same contents.
      Parameters:
      file1 - first file to compare
      file2 - second file to compare
      Returns:
      true iff the files have the same contents

    • equalFiles

      @Pure public static boolean equalFiles(String file1, String file2, boolean trimLines)
      Returns true iff the files have the same contents.
      Parameters:
      file1 - first file to compare
      file2 - second file to compare
      trimLines - if true, call String.trim on each line before comparing
      Returns:
      true iff the files have the same contents

    • canCreateAndWrite

      public static boolean canCreateAndWrite(File file)
      Returns true if the file exists and is writable, or if the file can be created.
      Parameters:
      file - the file to create and write
      Returns:
      true iff the file can be created and written

    • createTempFile

      public static Path createTempFile(String prefix, String suffix, FileAttribute<?>... attrs) throws IOException
      Creates a new empty file in the default temporary-file directory, using the given prefix and suffix strings to generate its name. This is like File.createTempFile(java.lang.String, java.lang.String, java.io.File), but uses sequential file names.
      Parameters:
      prefix - the prefix string to be used in generating the file's name; may be null
      suffix - the suffix string to be used in generating the file's name; may be null, in which case ".tmp" is used
      attrs - an optional list of file attributes to set atomically when creating the file
      Returns:
      the path to the newly created file that did not exist before this method was invoked
      Throws:
      IOException - if there is trouble creating the file

    • createTempFile

      public static Path createTempFile(Path dir, String prefix, String suffix, FileAttribute<?>... attrs) throws IOException
      Creates a new empty file in the specified directory, using the given prefix and suffix strings to generate its name. This is like File.createTempFile(java.lang.String, java.lang.String, java.io.File), but uses sequential file names.
      Parameters:
      dir - the path to directory in which to create the file
      prefix - the prefix string to be used in generating the file's name; may be null
      suffix - the suffix string to be used in generating the file's name; may be null, in which case ".tmp" is used
      attrs - an optional list of file attributes to set atomically when creating the file
      Returns:
      the path to the newly created file that did not exist before this method was invoked
      Throws:
      IOException - if there is trouble creating the file

    • createTempDir

      public static File createTempDir(String prefix, String suffix) throws IOException
      Creates an empty directory in the default temporary-file directory, using the given prefix and suffix to generate its name. For example, calling createTempDir("myPrefix", "mySuffix") will create the following directory: temporaryFileDirectory/myUserName/myPrefix_someString_suffix. someString is internally generated to ensure no temporary files of the same name are generated.
      Parameters:
      prefix - the prefix string to be used in generating the file's name; must be at least three characters long
      suffix - the suffix string to be used in generating the file's name; may be null, in which case the suffix ".tmp" will be used Returns: An abstract pathname denoting a newly-created empty file
      Returns:
      a File representing the newly-created temporary directory
      Throws:
      IllegalArgumentException - If the prefix argument contains fewer than three characters
      IOException - If a file could not be created
      SecurityException - If a security manager exists and its SecurityManager.checkWrite(java.lang.String) method does not allow a file to be created
      See Also:

    • deleteDir

      public static boolean deleteDir(String dirName)
      Deletes the directory at dirName and all its files. Also works on regular files.
      Parameters:
      dirName - the directory to delete
      Returns:
      true if and only if the file or directory is successfully deleted; false otherwise

    • deleteDir

      public static boolean deleteDir(File dir)
      Deletes the directory at dir and all its files. Also works on regular files.
      Parameters:
      dir - the directory to delete
      Returns:
      true if and only if the file or directory is successfully deleted; false otherwise

    • expandFilename

      public static File expandFilename(File name)
      Does tilde expansion on a file name (to the user's home directory).
      Parameters:
      name - file whose name to expand
      Returns:
      file with expanded file

    • expandFilename

      public static String expandFilename(String name)
      Does tilde expansion on a file name (to the user's home directory).
      Parameters:
      name - filename to expand
      Returns:
      expanded filename

    • javaSource

      public static String javaSource(File name)
      Returns a string version of the filename that can be used in Java source. On Windows, the file will return a backslash-separated string. Since backslash is an escape character, it must be quoted itself inside the string.

      The current implementation presumes that backslashes don't appear in filenames except as windows path separators. That seems like a reasonable assumption.

      Parameters:
      name - file whose name to quote
      Returns:
      a string version of the name that can be used in Java source

    • writeObject

      public static void writeObject(Object o, File file) throws IOException
      Writes an Object to a File.
      Parameters:
      o - the object to write
      file - the file to which to write the object
      Throws:
      IOException - if there is trouble writing the file

    • readObject

      public static Object readObject(File file) throws IOException, ClassNotFoundException
      Reads an Object from a File. This is a wrapper around ObjectInputStream.readObject(), but it takes a File as an argument. Note that use of that method can lead to security vulnerabilities.
      Parameters:
      file - the file from which to read
      Returns:
      the object read from the file
      Throws:
      IOException - if there is trouble reading the file
      ClassNotFoundException - if the object's class cannot be found

    • readerContents

      public static String readerContents(Reader r)
      Reads the entire contents of the reader and returns it as a string. Any IOException encountered will be turned into an Error.
      Parameters:
      r - the Reader to read; this method exhausts it and closes it
      Returns:
      the entire contents of the reader, as a string

    • readFile

      @Deprecated public static String readFile(File file)
      Deprecated.
      use readString(java.nio.file.Path)
      Reads the entire contents of the file and returns it as a string. Any IOException encountered will be turned into an Error.

      You could use new String(Files.readAllBytes(...)), but it requires a Path rather than a File, and it can throw IOException which has to be caught.

      Parameters:
      file - the file to read
      Returns:
      the entire contents of the reader, as a string

    • readString

      public static String readString(Path path)
      Reads the entire contents of the file and returns it as a string.

      The point of this method is that it does not throw any checked exception: any IOException encountered will be turned into an Error.

      Parameters:
      path - the path to the file
      Returns:
      a String containing the content read from the file

    • readLinesRetainingSeparators

      public static List<String> readLinesRetainingSeparators(Path path)
      Read the entire contents of the file and return it as a list of lines. Each line ends with a line separator (except perhaps the last line).
      Parameters:
      path - the path to the file
      Returns:
      the lines of the file

    • fileContents

      @Deprecated public static String fileContents(File file)
      Deprecated.
      use readString(java.nio.file.Path)
      Reads the entire contents of the file and returns it as a string.

      The point of this method is that it does not throw any checked exception: any IOException encountered will be turned into an Error.

      You could use new String(Files.readAllBytes(...)), but it requires a Path rather than a File, and it can throw IOException which has to be caught.

      Parameters:
      file - the file to read
      Returns:
      the entire contents of the reader, as a string

    • writeFile

      @Deprecated public static void writeFile(File file, String contents)
      Deprecated.
      use writeString(File, String)
      Creates a file with the given name and writes the specified string to it. If the file currently exists (and is writable) it is overwritten.

      The point of this method is that it does not throw any checked exception: any IOException encountered will be turned into an Error.

      Parameters:
      file - the file to write to
      contents - the text to put in the file

    • writeString

      public static void writeString(File file, String contents)
      Creates a file with the given name and writes the specified string to it. If the file currently exists (and is writable) it is overwritten.

      The point of this method is that it does not throw any checked exception: any IOException encountered will be turned into an Error.

      Parameters:
      file - the file to write to
      contents - the text to put in the file

    • writeString

      public static void writeString(Path path, String contents)
      Creates a file with the given name and writes the specified string to it. If the file currently exists (and is writable) it is overwritten Any IOException encountered will be turned into an Error.

      The point of this method is that it does not throw any checked exception: any IOException encountered will be turned into an Error.

      Parameters:
      path - the path to write to
      contents - the text to put in the file

    • streamCopy

      public static void streamCopy(InputStream from, OutputStream to)
      Copy the contents of the input stream to the output stream.
      Parameters:
      from - input stream
      to - output stream

    • streamString

      public static String streamString(InputStream is)
      Returns a String containing all the characters from the input stream.
      Parameters:
      is - input stream to read
      Returns:
      a String containing all the characters from the input stream

    • streamLines

      public static List<String> streamLines(InputStream stream) throws IOException
      Reads all lines from the stream and returns them in a List<String>.
      Parameters:
      stream - the stream to read from
      Returns:
      the list of lines read from the stream
      Throws:
      IOException - if there is an error reading from the stream

    • available

      public static @Nullable Integer available(InputStream is)
      Calls InputStream.available(), but returns null instead of throwing an IOException.
      Parameters:
      is - an input stream
      Returns:
      is.available(), or null if that throws an exception

    • isWhitespaceOnly

      public static @Nullable Boolean isWhitespaceOnly(InputStream is, @org.checkerframework.checker.index.qual.Positive int readLimit)
      Returns true if the first readLimit bytes of the input stream consist only of whitespace.
      Parameters:
      is - an input stream
      readLimit - how many bytes to look ahead in the input stream
      Returns:
      null if !is.markSupported(); otherwise, true if the first readLimit characters of the input stream consist only of whitespace

    • readCodePoint

      public static int readCodePoint(InputStream is)
      Reads a Unicode code point from an input stream.
      Parameters:
      is - an input stream
      Returns:
      the Unicode code point for the next character in the input stream