## net.i2p.util
Class FileUtil

    java.lang.Object
      net.i2p.util.FileUtil

    public class FileUtil

extends Object

General helper methods for messing with files These are static methods that do NOT convert arguments to absolute paths for a particular context and directtory. Callers should ALWAYS provide absolute paths as arguments, and should NEVER assume files are in the current working directory.

Constructor Summary
`FileUtil()`

Method Summary
`static boolean` `copy(String source, String dest, boolean overwriteExisting)`
`static boolean` `copy(String source, String dest, boolean overwriteExisting, boolean quiet)`
`static boolean` `extractZip(File zipfile, File targetDir)` As of release 0.7.12, any files inside the zip that have a .jar.pack or .war.pack suffix are transparently unpacked to a .jar or .war file using unpack200.
`static boolean` `isPack200Supported()` Public since 0.8.3
`static void` `main(String[] args)` Usage: FileUtil (delete path | copy source dest | unzip path.zip)
`static void` `readFile(String path, String root, OutputStream out)` Dump the contents of the given path (relative to the root) to the output stream.
`static String` `readTextFile(String filename, int maxNumLines, boolean startAtBeginning)` Read in the last few lines of a (newline delimited) textfile, or null if the file doesn't exist.
`static boolean` `rmdir(File target, boolean failIfNotEmpty)` Delete the path as well as any files or directories underneath it.
`static boolean` `rmdir(String path, boolean failIfNotEmpty)` Delete the path as well as any files or directories underneath it.
`static boolean` `verifyZip(File zipfile)` Verify the integrity of a zipfile.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### FileUtil

    public FileUtil()

Method Detail

### rmdir

    public static final boolean rmdir(String path,
                                      boolean failIfNotEmpty)

  Delete the path as well as any files or directories underneath it.

  Parameters:
    `path` - path to the directory being deleted
    `failIfNotEmpty` - if true, do not delete anything if the directory is not empty (and return false)
  Returns:
    true if the path no longer exists (aka was removed), false if it remains

### rmdir

    public static final boolean rmdir(File target,
                                      boolean failIfNotEmpty)

  Delete the path as well as any files or directories underneath it.

  Parameters:
    `target` - the file or directory being deleted
    `failIfNotEmpty` - if true, do not delete anything if the directory is not empty (and return false)
  Returns:
    true if the path no longer exists (aka was removed), false if it remains

### extractZip

    public static boolean extractZip(File zipfile,
                                     File targetDir)

  As of release 0.7.12, any files inside the zip that have a .jar.pack or .war.pack suffix are transparently unpacked to a .jar or .war file using unpack200.

### verifyZip

    public static boolean verifyZip(File zipfile)

  Verify the integrity of a zipfile. There doesn't seem to be any library function to do this, so we basically go through all the motions of extractZip() above, unzipping everything but throwing away the data. Todo: verify zip header? Although this would break the undocumented practice of renaming the i2pupdate.sud file to i2pupdate.zip and letting the unzip method skip over the leading 56 bytes of "junk" (sig and version)

  Returns:
    true if ok

### isPack200Supported

    public static boolean isPack200Supported()

  Public since 0.8.3

  Since:
    0.8.1

### readTextFile

    public static String readTextFile(String filename,
                                      int maxNumLines,
                                      boolean startAtBeginning)

  Read in the last few lines of a (newline delimited) textfile, or null if the file doesn't exist. Warning - this inefficiently allocates a StringBuilder of size maxNumLines*80, so don't make it too big. Warning - converts \r\n to \n

  Parameters:
    `startAtBeginning` - if true, read the first maxNumLines, otherwise read the last maxNumLines
    `maxNumLines` - max number of lines (or -1 for unlimited)
  Returns:
    string or null; does not throw IOException.

### readFile

    public static void readFile(String path,
                                String root,
                                OutputStream out)
                         throws IOException

  Dump the contents of the given path (relative to the root) to the output stream. The path must not go above the root, either - if it does, it will throw a FileNotFoundException Closes the OutputStream out on successful completion but leaves it open when throwing IOE.

  Throws:
    `IOException`

### copy

    public static boolean copy(String source,
                               String dest,
                               boolean overwriteExisting)

  Returns:
    true if it was copied successfully

### copy

    public static boolean copy(String source,
                               String dest,
                               boolean overwriteExisting,
                               boolean quiet)

  Parameters:
    `quiet` - don't log fails to wrapper log if true
  Returns:
    true if it was copied successfully

### main

    public static void main(String[] args)

  Usage: FileUtil (delete path | copy source dest | unzip path.zip)