zcommon/src/main/java/org/zkoss/io/Files.java
/* Files.java
Purpose: File related utilities.
Description:
History:
2001/6/29, Tom M. Yeh: Created.
Copyright (C) 2001 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under LGPL Version 2.1 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Writer;
import java.io.Reader;
import java.io.ByteArrayOutputStream;
import java.io.StringWriter;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.util.Locale;
import org.slf4j.Logger;
import org.zkoss.util.Locales;
/**
* File related utilities.
*
* @author tomyeh
*/
public class Files {
protected Files() {}
private static final Logger log = org.slf4j.LoggerFactory.getLogger(Files.class);
/**
* The separator representing the drive in a path. In Windows, it is
* ':', while 0 in other platforms.
*/
public final static char DRIVE_SEPARATOR_CHAR =
System.getProperty("os.name").indexOf("Windows")<0 ? (char)0: ':';
/** Corrects the separator from '/' to the system dependent one.
* Note: always uses '/' even though Windows uses '\\'.
*/
public final static String correctSeparator(String flnm) {
return File.separatorChar != '/' ?
flnm.replace('/', File.separatorChar): flnm;
}
/** Returns all bytes in the input stream, never null
* (but its length might zero).
* <p>Notice: this method is memory hungry.
* <p>Notice: it doesn't close <code>in</code>
*/
public static final byte[] readAll(InputStream in)
throws IOException {
final ByteArrayOutputStream out = new ByteArrayOutputStream();
final byte[] buf = new byte[1024*16];
for (int v; (v = in.read(buf)) >= 0;) { //including 0
out.write(buf, 0, v);
}
return out.toByteArray();
}
/** Returns all characters in the reader, never null
* (but its length might zero).
* <p>Notice: this method is memory hungry.
*/
public static final StringBuffer readAll(Reader reader)
throws IOException {
final StringWriter writer = new StringWriter(1024*16);
copy(writer, reader);
return writer.getBuffer();
}
/** Copies a reader into a writer.
* <p>Notice: it doesn't close <code>reader</code> or <code>writer</code>
* @param writer the destination
* @param reader the source
*/
public static final void copy(Writer writer, Reader reader)
throws IOException {
final char[] buf = new char[1024*4];
for (int v; (v = reader.read(buf)) >= 0;) {
if (v > 0)
writer.write(buf, 0, v);
}
}
/** Copies an input stream to a output stream.
* <p>Notice: it doesn't close <code>in</code> or <code>out</code>
* @param out the destination
* @param in the source
*/
public static final void copy(OutputStream out, InputStream in)
throws IOException {
final byte[] buf = new byte[1024*8];
for (int v; (v = in.read(buf)) >= 0;) {
if (v > 0)
out.write(buf, 0, v);
}
}
/** Copies a reader into a file (the original content, if any, are erased).
* The source and destination files will be closed after copied.
*
* @param dst the destination
* @param reader the source
* @param charset the charset; null as default (ISO-8859-1).
*/
public static final void copy(File dst, Reader reader, String charset)
throws IOException {
final File parent = dst.getParentFile();
if (parent != null)
parent.mkdirs();
final Writer writer = charset != null ?
(Writer)new FileWriter(dst, charset): new java.io.FileWriter(dst);
try {
copy(writer, reader);
} finally {
close(reader);
writer.close();
}
}
/** Copies an input stream into a file
* (the original content, if any, are erased).
* The file will be closed after copied.
* @param dst the destination
* @param in the source
*/
public static final void copy(File dst, InputStream in)
throws IOException {
final File parent = dst.getParentFile();
if (parent != null)
parent.mkdirs();
final OutputStream out =
new BufferedOutputStream(new FileOutputStream(dst));
try {
copy(out, in);
} finally {
close(in);
out.close();
}
}
/** Preserves the last modified time and other attributes if possible.
* @see #copy(File, File, int)
*/
public static int CP_PRESERVE = 0x0001;
/** Copy only when the source is newer or when the destination is missing.
* @see #copy(File, File, int)
*/
public static int CP_UPDATE = 0x0002;
/** Overwrites the destination file.
* @see #copy(File, File, int)
*/
public static int CP_OVERWRITE = 0x0004;
/** Skips the SVN related files.
* @since 5.0.0
*/
public static int CP_SKIP_SVN = 0x1000;
/** Copies a file or a directory into another.
*
* <p>If neither {@link #CP_UPDATE} nor {@link #CP_OVERWRITE},
* IOException is thrown if the destination exists.
*
* @param flags any combination of {@link #CP_UPDATE}, {@link #CP_PRESERVE},
* {@link #CP_OVERWRITE}.
*/
public static final void copy(File dst, File src, int flags)
throws IOException {
if (!src.exists())
throw new FileNotFoundException(src.toString());
if (dst.isDirectory()) {
if (src.isDirectory()) {
copyDir(dst, src, flags);
} else {
copyFile(new File(dst, src.getName()), src, flags);
}
} else if (dst.isFile()) {
if (src.isDirectory()) {
throw new IOException("Unable to copy a directory, "+src+", to a file, "+dst);
} else {
copyFile(dst, src, flags);
}
} else {
if (src.isDirectory()) {
copyDir(dst, src, flags);
} else {
copyFile(dst, src, flags);
}
}
}
/** Assumes both dst and src is a file. */
private static final void copyFile(File dst, File src, int flags)
throws IOException {
if (dst.equals(src))
throw new IOException("Copy to the same file, "+src);
if ((flags & CP_OVERWRITE) == 0) {
if ((flags & CP_UPDATE) != 0) {
if (dst.lastModified() >= src.lastModified())
return; //nothing to do
} else if (dst.exists()) {
throw new IOException("The destination already exists, "+dst);
}
}
InputStream is = new BufferedInputStream(new FileInputStream(src));
try {
copy(dst, is);
} finally {
close(is);
}
if ((flags & CP_PRESERVE) != 0 && (!dst.setLastModified(src.lastModified()))) {
log.warn("Unable to set the last modified time of {}", dst);
}
}
/** Assumes both dst and src is a directory. */
private static final void copyDir(File dst, File src, int flags)
throws IOException {
if ((flags & CP_SKIP_SVN) != 0 && ".svn".equals(src.getName()))
return; //skip
final File[] srcs = src.listFiles();
for (int j = 0; j < srcs.length; ++j) {
copy(new File(dst, srcs[j].getName()), srcs[j], flags); //recursive
}
}
/** Deletes all files under the specified path.
*/
public static final boolean deleteAll(File file) {
if (file.isDirectory()) {
final File[] fls = file.listFiles();
for (int j = 0; j < fls.length; ++j) {
if (!deleteAll(fls[j]))
return false;
//failed as soon as possible to avoid removing extra files
}
}
return file.delete();
}
/** Close an input stream without throwing an exception.
*/
public static final void close(InputStream strm) {
if (strm != null) {
try {
strm.close();
} catch (IOException ex) { //ignore it
// System.out.println("Unable to close an input stream");
}
}
}
/** Close a reader without throwing an exception.
*/
public static final void close(Reader reader) {
if (reader != null) {
try {
reader.close();
} catch (IOException ex) { //ignore it
// System.out.println("Unable to close a reader");
}
}
}
/** Close an output stream without throwing an exception.
* @since 5.0.4
*/
public static final void close(OutputStream strm) {
if (strm != null) {
try {
strm.close();
} catch (IOException ex) { //ignore it
// System.out.println("Unable to close an output stream");
}
}
}
/** Close a writer without throwing an exception.
* @since 5.0.4
*/
public static final void close(Writer writer) {
if (writer != null) {
try {
writer.close();
} catch (IOException ex) { //ignore it
// System.out.println("Unable to close a writer");
}
}
}
/** Normalizes the concatenation of two paths.
*
* @param parentPath the parent's path
* @param childPath the child's path
* If it starts with "/", parentPath is ignored.
* @since 5.0.0
*/
public static final String normalize(String parentPath, String childPath) {
if (childPath == null || childPath.length() == 0)
return normalize(parentPath);
if ((parentPath == null || parentPath.length() == 0)
|| childPath.charAt(0) == '/')
return normalize(childPath);
if (parentPath.charAt(parentPath.length() - 1) == '/')
return normalize(parentPath + childPath);
return normalize(parentPath + '/' + childPath);
}
/**
* Normalizes the specified path.
* It removes consecutive slashes, ending slashes,
* redundant . and ...
* <p>Unlike {@link File}, {@link #normalize} always assumes
* the separator to be '/', and it cannot handle the device prefix
* (e.g., c:). However, it handles //.
*
* @param path the path to normalize. If null, an empty string is returned.
* @since 5.0.0
*/
public static final String normalize(String path) {
if (path == null)
return "";
//remove consecutive slashes
final StringBuffer sb = new StringBuffer(path);
boolean slash = false;
for (int j = 0, len = sb.length(); j < len; ++j) {
final boolean curslash = sb.charAt(j) == '/';
if (curslash && slash && j != 1) {
sb.deleteCharAt(j);
--j; --len;
}
slash = curslash;
}
if (sb.length() > 1 && slash) //remove ending slash except "/"
sb.setLength(sb.length() - 1);
//remove ./
while (sb.length() >= 2 && sb.charAt(0) == '.' && sb.charAt(1) == '/')
sb.delete(0, 2); // "./" -> ""
//remove /./
for (int j = 0; (j = sb.indexOf( "/./", j)) >= 0;)
sb.delete(j + 1, j + 3); // "/./" -> "/"
//ends with "/."
int len = sb.length();
if (len >= 2 && sb.charAt(len - 1) == '.' && sb.charAt(len - 2) == '/')
if (len == 2) return "/";
else sb.delete(len - 2, len);
//remove /../
for (int j = 0; (j = sb.indexOf("/../", j)) >= 0;)
j = removeDotDot(sb, j);
// ends with "/.."
len = sb.length();
if (len >= 3 && sb.charAt(len - 1) == '.' && sb.charAt(len - 2) == '.'
&& sb.charAt(len - 3) == '/')
if (len == 3) return "/";
else removeDotDot(sb, len - 3);
return sb.length() == path.length() ? path: sb.toString();
}
/** Removes "/..".
* @param j points '/' in "/.."
* @return the next index to search from
*/
private static int removeDotDot(StringBuffer sb, int j) {
int k = j;
while (--k >= 0 && sb.charAt(k) != '/')
;
if (k + 3 == j && sb.charAt(k + 1) == '.' && sb.charAt(k + 2) == '.')
return j + 4; // don't touch: "../.."
sb.delete(j, j + 3); // "/.." -> ""
if (j == 0) // "/.."
return 0;
if (k < 0) { // "a/+" => kill "a/", "a" => kill a
sb.delete(0, j < sb.length() ? j + 1: j);
return 0;
}
// "/a/+" => kill "/a", "/a" => kill "a"
if (j >= sb.length()) ++k;
sb.delete(k, j);
return k;
}
/** Writes the specified string buffer to the specified writer.
* Use this method instead of out.write(sb.toString()), if sb.length()
* is large.
* @since 5.0.0
*/
public static final void write(Writer out, StringBuffer sb)
throws IOException {
//Don't convert sb to String to save the memory use
for (int j = 0, len = sb.length(); j < len; ++j)
out.write(sb.charAt(j));
}
/** Locates a file based o the current Locale. It never returns null.
*
* <p>If the filename contains "*", it will be replaced with a proper Locale.
* For example, if the current Locale is zh_TW and the resource is
* named "ab*.cd", then it searches "ab_zh_TW.cd", "ab_zh.cd" and
* then "ab.cd", until any of them is found.
*
* <blockquote>Note: "*" must be right before ".", or the last character.
* For example, "ab*.cd" and "ab*" are both correct, while
* "ab*cd" and "ab*\/cd" are ignored.</blockquote>
*
* <p>Unlike {@link org.zkoss.util.resource.Locators#locate}, the filename
* must contain '*', while {@link org.zkoss.util.resource.Locators#locate}
* always tries to locate the file by
* inserting the locale before '.'. In other words,
* Files.locate("/a/b*.c") is similar to
* Locators.locate(("/a/b.c", null, a_file_locator);
*
* @param flnm the filename to locate. If it doesn't contain any '*',
* it is returned directly. If the file is not found, flnm is returned, too.
* @see Locales#getCurrent
* @since 5.0.0
*/
public static final String locate(String flnm) {
int j = flnm.indexOf('*');
if (j < 0) return flnm;
final String postfix = flnm.substring(j + 1);
final Locale locale = Locales.getCurrent();
final String[] secs = new String[] {
locale.getLanguage(), locale.getCountry(), locale.getVariant()
};
final StringBuffer sb = new StringBuffer(flnm.substring(0, j));
final int prefixlen = sb.length();
for (j = secs.length;;) {
if (--j >= 0 && secs[j].length() == 0)
continue;
sb.setLength(prefixlen);
for (int k = 0; k <= j; ++k)
sb.append('_').append(secs[k]);
sb.append(postfix);
flnm = sb.toString();
if (j < 0 || new File(flnm).exists()) return flnm;
}
}
}