com.google.gwt.dev.util.Util Maven / Gradle / Ivy
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/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.dev.util;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.util.log.speedtracer.CompilerEventType;
import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger;
import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger.Event;
import com.google.gwt.util.tools.Utility;
import com.google.gwt.util.tools.shared.StringUtils;
import org.w3c.dom.Attr;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileFilter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Array;
import java.net.JarURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Collection;
/**
* A smattering of useful methods. Methods in this class are candidates for
* being moved to {@link com.google.gwt.util.tools.Utility} if they would be
* generally useful to tool writers, and don't involve TreeLogger.
*/
// TODO: remove stream functions and replace with Guava.
public final class Util {
public static String DEFAULT_ENCODING = "UTF-8";
private static final String FILE_PROTOCOL = "file";
private static final String JAR_PROTOCOL = "jar";
/**
* The size of a {@link #threadLocalBuf}, which should be large enough for
* efficient data transfer but small enough to fit easily into the L2 cache of
* most modern processors.
*/
private static final int THREAD_LOCAL_BUF_SIZE = 16 * 1024;
/**
* Stores reusable thread local buffers for efficient data transfer.
*/
private static final ThreadLocal threadLocalBuf = new ThreadLocal();
/**
* Computes the MD5 hash for the specified byte array.
*
* @return a big fat string encoding of the MD5 for the content, suitably
* formatted for use as a file name
*/
public static String computeStrongName(byte[] content) {
return computeStrongName(new byte[][] {content});
}
/**
* Computes the MD5 hash of the specified byte arrays.
*
* @return a big fat string encoding of the MD5 for the content, suitably
* formatted for use as a file name
*/
public static String computeStrongName(byte[][] contents) {
MessageDigest md5;
try {
md5 = MessageDigest.getInstance("MD5");
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException("Error initializing MD5", e);
}
/*
* Include the lengths of the contents components in the hash, so that the
* hashed sequence of bytes is in a one-to-one correspondence with the
* possible arguments to this method.
*/
ByteBuffer b = ByteBuffer.allocate((contents.length + 1) * 4);
b.putInt(contents.length);
for (int i = 0; i < contents.length; i++) {
b.putInt(contents[i].length);
}
b.flip();
md5.update(b);
// Now hash the actual contents of the arrays
for (int i = 0; i < contents.length; i++) {
md5.update(contents[i]);
}
return StringUtils.toHexString(md5.digest());
}
public static void copy(InputStream is, OutputStream os) throws IOException {
try {
copyNoClose(is, os);
} finally {
Utility.close(is);
Utility.close(os);
}
}
/**
* Copies an input stream out to an output stream. Closes the input steam and
* output stream.
*/
public static void copy(TreeLogger logger, InputStream is, OutputStream os)
throws UnableToCompleteException {
try {
copy(is, os);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Error during copy", e);
throw new UnableToCompleteException();
}
}
/**
* Copies all of the bytes from the input stream to the output stream until
* the input stream is EOF. Does not close either stream.
*/
public static void copyNoClose(InputStream is, OutputStream os)
throws IOException {
byte[] buf = takeThreadLocalBuf();
try {
int i;
while ((i = is.read(buf)) != -1) {
os.write(buf, 0, i);
}
} finally {
releaseThreadLocalBuf(buf);
}
}
public static Reader createReader(TreeLogger logger, URL url)
throws UnableToCompleteException {
try {
return new InputStreamReader(url.openStream());
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to open resource: " + url, e);
throw new UnableToCompleteException();
}
}
/**
* Equality check through equals() that is also satisfied if both objects are null.
*/
public static boolean equalsNullCheck(Object thisObject, Object thatObject) {
if (thisObject == null) {
return thatObject == null;
}
return thisObject.equals(thatObject);
}
/**
* Escapes '&', '<', '>', '"', and '\'' to their XML entity equivalents.
*/
public static String escapeXml(String unescaped) {
StringBuilder builder = new StringBuilder();
escapeXml(unescaped, 0, unescaped.length(), true, builder);
return builder.toString();
}
/**
* Escapes '&', '<', '>', '"', and optionally ''' to their XML entity
* equivalents. The portion of the input string between start (inclusive) and
* end (exclusive) is scanned. The output is appended to the given
* StringBuilder.
*
* @param code the input String
* @param start the first character position to scan.
* @param end the character position following the last character to scan.
* @param quoteApostrophe if true, the ' character is quoted as
* '
* @param builder a StringBuilder to be appended with the output.
*/
public static void escapeXml(String code, int start, int end,
boolean quoteApostrophe, StringBuilder builder) {
int lastIndex = 0;
int len = end - start;
char[] c = new char[len];
code.getChars(start, end, c, 0);
for (int i = 0; i < len; i++) {
switch (c[i]) {
case '&':
builder.append(c, lastIndex, i - lastIndex);
builder.append("&");
lastIndex = i + 1;
break;
case '>':
builder.append(c, lastIndex, i - lastIndex);
builder.append(">");
lastIndex = i + 1;
break;
case '<':
builder.append(c, lastIndex, i - lastIndex);
builder.append("<");
lastIndex = i + 1;
break;
case '\"':
builder.append(c, lastIndex, i - lastIndex);
builder.append(""");
lastIndex = i + 1;
break;
case '\'':
if (quoteApostrophe) {
builder.append(c, lastIndex, i - lastIndex);
builder.append("'");
lastIndex = i + 1;
}
break;
default:
break;
}
}
builder.append(c, lastIndex, len - lastIndex);
}
public static URL findSourceInClassPath(ClassLoader cl, String sourceTypeName) {
String toTry = sourceTypeName.replace('.', '/') + ".java";
URL foundURL = cl.getResource(toTry);
if (foundURL != null) {
return foundURL;
}
int i = sourceTypeName.lastIndexOf('.');
if (i != -1) {
return findSourceInClassPath(cl, sourceTypeName.substring(0, i));
} else {
return null;
}
}
/**
* Returns a byte-array representing the default encoding for a String.
*/
public static byte[] getBytes(String s) {
try {
return s.getBytes(DEFAULT_ENCODING);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(
"The JVM does not support the compiler's default encoding.", e);
}
}
/**
* @param className A fully-qualified class name whose name you want.
* @return The base name for the specified class.
*/
public static String getClassName(String className) {
return className.substring(className.lastIndexOf('.') + 1);
}
/**
* Gets the contents of a file.
*
* @param relativePath relative path within the install directory
* @return the contents of the file, or null if an error occurred
*/
public static String getFileFromInstallPath(String relativePath) {
String installPath = Utility.getInstallPath();
File file = new File(installPath + '/' + relativePath);
return readFileAsString(file);
}
/**
* @param qualifiedName A fully-qualified class name whose package name you want.
* @return The package name for the specified class, empty string if default package.
*/
public static String getPackageName(String qualifiedName) {
int idx = qualifiedName.lastIndexOf('.');
if (idx > 0) {
return qualifiedName.substring(0, idx);
}
return "";
}
/**
* Retrieves the last modified time of a provided URL.
*
* @return a positive value indicating milliseconds since the epoch (00:00:00
* Jan 1, 1970), or 0L on failure, such as a SecurityException or
* IOException.
*/
public static long getResourceModifiedTime(URL url) {
long lastModified = 0L;
try {
if (url.getProtocol().equals(JAR_PROTOCOL)) {
/*
* If this resource is contained inside a jar file, such as can happen
* if it's bundled in a 3rd-party library, we use the jar file itself to
* test whether it's up to date. We don't want to call
* JarURLConnection.getLastModified(), as this is much slower than using
* the jar File resource directly.
*/
JarURLConnection jarConn = (JarURLConnection) url.openConnection();
url = jarConn.getJarFileURL();
}
if (url.getProtocol().equals(FILE_PROTOCOL)) {
/*
* Need to handle possibly wonky syntax in a file URL resource. Modeled
* after suggestion in this blog entry:
* http://weblogs.java.net/blog/2007
* /04/25/how-convert-javaneturl-javaiofile
*/
File file;
try {
file = new File(url.toURI());
} catch (URISyntaxException uriEx) {
file = new File(url.getPath());
}
lastModified = file.lastModified();
}
} catch (IOException ignored) {
} catch (RuntimeException ignored) {
}
return lastModified;
}
public static boolean isValidJavaIdent(String token) {
if (token.length() == 0) {
return false;
}
if (!Character.isJavaIdentifierStart(token.charAt(0))) {
return false;
}
for (int i = 1, n = token.length(); i < n; i++) {
if (!Character.isJavaIdentifierPart(token.charAt(i))) {
return false;
}
}
return true;
}
/**
* Attempts to make a path relative to a particular directory.
*
* @param from the directory from which 'to' should be relative
* @param to an absolute path which will be returned so that it is relative to
* 'from'
* @return the relative path, if possible; null otherwise
*/
public static File makeRelativeFile(File from, File to) {
// Keep ripping off directories from the 'from' path until the 'from' path
// is a prefix of the 'to' path.
//
String toPath = tryMakeCanonical(to).getAbsolutePath();
File currentFrom = tryMakeCanonical(from.isDirectory() ? from
: from.getParentFile());
int numberOfBackups = 0;
while (currentFrom != null) {
String currentFromPath = currentFrom.getPath();
if (toPath.startsWith(currentFromPath)) {
// Found a prefix!
//
break;
} else {
++numberOfBackups;
currentFrom = currentFrom.getParentFile();
}
}
if (currentFrom == null) {
// Cannot make it relative.
//
return null;
}
// Find everything to the right of the common prefix.
//
String trailingToPath = toPath.substring(currentFrom.getAbsolutePath().length());
if (currentFrom.getParentFile() != null && trailingToPath.length() > 0) {
trailingToPath = trailingToPath.substring(1);
}
File relativeFile = new File(trailingToPath);
for (int i = 0; i < numberOfBackups; ++i) {
relativeFile = new File("..", relativeFile.getPath());
}
return relativeFile;
}
public static String makeRelativePath(File from, File to) {
File f = makeRelativeFile(from, to);
return (f != null ? f.getPath() : null);
}
public static byte[] readFileAsBytes(File file) {
FileInputStream fileInputStream = null;
try {
fileInputStream = new FileInputStream(file);
int length = (int) file.length();
return readBytesFromInputStream(fileInputStream, length);
} catch (IOException e) {
return null;
} finally {
Utility.close(fileInputStream);
}
}
public static T readFileAsObject(File file,
Class type) throws ClassNotFoundException, IOException {
FileInputStream fileInputStream = null;
try {
fileInputStream = new FileInputStream(file);
return readStreamAsObject(fileInputStream, type);
} finally {
Utility.close(fileInputStream);
}
}
public static String readFileAsString(File file) {
byte[] bytes = readFileAsBytes(file);
if (bytes != null) {
return toString(bytes, DEFAULT_ENCODING);
}
return null;
}
/**
* Reads an entire input stream as bytes. Closes the input stream.
*/
public static byte[] readStreamAsBytes(InputStream in) {
try {
ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
copy(in, out);
return out.toByteArray();
} catch (IOException e) {
return null;
}
}
public static T readStreamAsObject(InputStream inputStream, Class type)
throws ClassNotFoundException, IOException {
ObjectInputStream objectInputStream = null;
try {
objectInputStream = new StringInterningObjectInputStream(inputStream);
return type.cast(objectInputStream.readObject());
} finally {
Utility.close(objectInputStream);
}
}
/**
* Reads an entire input stream as String. Closes the input stream.
*/
public static String readStreamAsString(InputStream in) {
try {
ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
copy(in, out);
return out.toString(DEFAULT_ENCODING);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(
"The JVM does not support the compiler's default encoding.", e);
} catch (IOException e) {
// TODO(zundel): Consider allowing this exception out. The pattern in this
// file is to convert IOException to null, but in references to this
// method, there are few places that check for null and do something sane,
// the rest just throw an NPE and obscure the root cause.
return null;
}
}
/**
* @return null if the file could not be read
*/
public static byte[] readURLAsBytes(URL url) {
try {
URLConnection conn = url.openConnection();
conn.setUseCaches(false);
return readURLConnectionAsBytes(conn);
} catch (IOException e) {
return null;
}
}
/**
* @return null if the file could not be read
*/
public static char[] readURLAsChars(URL url) {
byte[] bytes = readURLAsBytes(url);
if (bytes != null) {
return toString(bytes, DEFAULT_ENCODING).toCharArray();
}
return null;
}
/**
* @return null if the file could not be read
*/
public static String readURLAsString(URL url) {
byte[] bytes = readURLAsBytes(url);
if (bytes != null) {
return toString(bytes, DEFAULT_ENCODING);
}
return null;
}
public static byte[] readURLConnectionAsBytes(URLConnection connection) {
// ENH: add a weak cache that has an additional check against the file date
InputStream input = null;
try {
input = connection.getInputStream();
int contentLength = connection.getContentLength();
if (contentLength < 0) {
return null;
}
return readBytesFromInputStream(input, contentLength);
} catch (IOException e) {
return null;
} finally {
Utility.close(input);
}
}
/**
* Deletes a file or recursively deletes a directory.
*
* @param file the file to delete, or if this is a directory, the directory
* that serves as the root of a recursive deletion
* @param childrenOnly if true, only the children of a
* directory are recursively deleted but the specified directory
* itself is spared; if false, the specified
* directory is also deleted; ignored if file is not a
* directory
*/
public static void recursiveDelete(File file, boolean childrenOnly) {
recursiveDelete(file, childrenOnly, null);
}
/**
* Selectively deletes a file or recursively deletes a directory. Note that
* it is possible that files remain if file.delete() fails.
*
* @param file the file to delete, or if this is a directory, the directory
* that serves as the root of a recursive deletion
* @param childrenOnly if true, only the children of a
* directory are recursively deleted but the specified directory
* itself is spared; if false, the specified
* directory is also deleted; ignored if file is not a
* directory
* @param filter only files matching this filter will be deleted
*/
public static void recursiveDelete(File file, boolean childrenOnly,
FileFilter filter) {
if (file.isDirectory()) {
File[] children = file.listFiles();
if (children != null) {
for (int i = 0; i < children.length; i++) {
recursiveDelete(children[i], false, filter);
}
}
if (childrenOnly) {
// Do not delete the specified directory itself.
return;
}
}
if (filter == null || filter.accept(file)) {
file.delete();
}
}
/**
* Release a buffer previously returned from {@link #takeThreadLocalBuf()}.
* The released buffer may then be reused.
*/
public static void releaseThreadLocalBuf(byte[] buf) {
assert buf.length == THREAD_LOCAL_BUF_SIZE;
threadLocalBuf.set(buf);
}
/**
* Remove leading file:jar:...!/ prefix from source paths for source located in jars.
* @param absolutePath an absolute JAR file URL path
* @return the location of the file within the JAR
*/
public static String stripJarPathPrefix(String absolutePath) {
if (absolutePath != null) {
int bang = absolutePath.lastIndexOf('!');
if (bang != -1) {
return absolutePath.substring(bang + 2);
}
}
return absolutePath;
}
/**
* Get a large byte buffer local to this thread. Currently this is set to a
* 16k buffer, which is small enough to fit into the L2 cache on modern
* processors. The contents of the returned buffer are undefined. Calling
* {@link #releaseThreadLocalBuf(byte[])} on the returned buffer allows
* subsequent callers to reuse the buffer later, avoiding unncessary
* allocations and GC.
*/
public static byte[] takeThreadLocalBuf() {
byte[] buf = threadLocalBuf.get();
if (buf == null) {
buf = new byte[THREAD_LOCAL_BUF_SIZE];
} else {
threadLocalBuf.set(null);
}
return buf;
}
/**
* Creates an array from a collection of the specified component type and
* size. You can definitely downcast the result to T[] if T is the specified
* component type.
*
* Class is used to allow creation of generic types, such as
* Map.Entry since we can only pass in Map.Entry.class.
*/
@SuppressWarnings("unchecked")
public static T[] toArray(Class componentType,
Collection coll) {
int n = coll.size();
T[] a = (T[]) Array.newInstance(componentType, n);
return coll.toArray(a);
}
/**
* Returns a String representing the character content of the bytes; the bytes
* must be encoded using the compiler's default encoding.
*/
public static String toString(byte[] bytes) {
return toString(bytes, DEFAULT_ENCODING);
}
/**
* Attempts to find the canonical form of a file path.
*
* @return the canonical version of the file path, if it could be computed;
* otherwise, the original file is returned unmodified
*/
public static File tryMakeCanonical(File file) {
try {
return file.getCanonicalFile();
} catch (IOException e) {
return file;
}
}
public static void writeBytesToFile(TreeLogger logger, File where, byte[] what)
throws UnableToCompleteException {
writeBytesToFile(logger, where, new byte[][] {what});
}
/**
* Gathering write.
*/
public static void writeBytesToFile(TreeLogger logger, File where,
byte[][] what) throws UnableToCompleteException {
FileOutputStream f = null;
Throwable caught;
try {
// No need to check mkdirs result because an IOException will occur anyway
where.getParentFile().mkdirs();
f = new FileOutputStream(where);
for (int i = 0; i < what.length; i++) {
f.write(what[i]);
}
return;
} catch (FileNotFoundException e) {
caught = e;
} catch (IOException e) {
caught = e;
} finally {
Utility.close(f);
}
String msg = "Unable to write file '" + where + "'";
logger.log(TreeLogger.ERROR, msg, caught);
throw new UnableToCompleteException();
}
/**
* Serializes an object and writes it to a file.
*/
public static void writeObjectAsFile(TreeLogger logger, File file,
Object... objects) throws UnableToCompleteException {
Event writeObjectAsFileEvent = SpeedTracerLogger.start(CompilerEventType.WRITE_OBJECT_AS_FILE);
FileOutputStream stream = null;
try {
// No need to check mkdirs result because an IOException will occur anyway
file.getParentFile().mkdirs();
stream = new FileOutputStream(file);
writeObjectToStream(stream, objects);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to write file: "
+ file.getAbsolutePath(), e);
throw new UnableToCompleteException();
} finally {
Utility.close(stream);
writeObjectAsFileEvent.end();
}
}
/**
* Serializes an object and writes it to a stream.
*/
public static void writeObjectToStream(OutputStream stream, Object... objects)
throws IOException {
ObjectOutputStream objectStream = null;
objectStream = new ObjectOutputStream(stream);
for (Object object : objects) {
objectStream.writeObject(object);
}
objectStream.flush();
}
public static boolean writeStringAsFile(File file, String string) {
FileOutputStream stream = null;
OutputStreamWriter writer = null;
BufferedWriter buffered = null;
try {
// No need to check mkdirs result because an IOException will occur anyway
file.getParentFile().mkdirs();
stream = new FileOutputStream(file);
writer = new OutputStreamWriter(stream, DEFAULT_ENCODING);
buffered = new BufferedWriter(writer);
buffered.write(string);
} catch (IOException e) {
return false;
} finally {
Utility.close(buffered);
Utility.close(writer);
Utility.close(stream);
}
return true;
}
public static void writeStringAsFile(TreeLogger logger, File file,
String string) throws UnableToCompleteException {
FileOutputStream stream = null;
OutputStreamWriter writer = null;
BufferedWriter buffered = null;
try {
stream = new FileOutputStream(file);
writer = new OutputStreamWriter(stream, DEFAULT_ENCODING);
buffered = new BufferedWriter(writer);
// No need to check mkdirs result because an IOException will occur anyway
file.getParentFile().mkdirs();
buffered.write(string);
} catch (IOException e) {
logger.log(TreeLogger.ERROR, "Unable to write file: "
+ file.getAbsolutePath(), e);
throw new UnableToCompleteException();
} finally {
Utility.close(buffered);
Utility.close(writer);
Utility.close(stream);
}
}
/**
* Writes the contents of a StringBuilder to an OutputStream, encoding
* each character using the UTF-* encoding. Unicode characters between
* U+0000 and U+10FFFF are supported.
*/
public static void writeUtf8(StringBuilder builder, OutputStream out)
throws IOException {
// Rolling our own converter avoids the following:
//
// o Instantiating the entire builder as a String
// o Creating CharEncoders and NIO buffer
// o Passing through an OutputStreamWriter
int buflen = 1024;
char[] inBuf = new char[buflen];
byte[] outBuf = new byte[4 * buflen];
int length = builder.length();
int start = 0;
while (start < length) {
int end = Math.min(start + buflen, length);
builder.getChars(start, end, inBuf, 0);
int index = 0;
int len = end - start;
for (int i = 0; i < len; i++) {
int c = inBuf[i] & 0xffff;
if (c < 0x80) {
outBuf[index++] = (byte) c;
} else if (c < 0x800) {
int y = c >> 8;
int x = c & 0xff;
outBuf[index++] = (byte) (0xc0 | (y << 2) | (x >> 6)); // 110yyyxx
outBuf[index++] = (byte) (0x80 | (x & 0x3f)); // 10xxxxxx
} else if (c < 0xD800 || c > 0xDFFF) {
int y = (c >> 8) & 0xff;
int x = c & 0xff;
outBuf[index++] = (byte) (0xe0 | (y >> 4)); // 1110yyyy
outBuf[index++] = (byte) (0x80 | ((y << 2) & 0x3c) | (x >> 6)); // 10yyyyxx
outBuf[index++] = (byte) (0x80 | (x & 0x3f)); // 10xxxxxx
} else {
// Ignore if no second character (which is not be legal unicode)
if (i + 1 < len) {
int hi = c & 0x3ff;
int lo = inBuf[i + 1] & 0x3ff;
int full = 0x10000 + ((hi << 10) | lo);
int z = (full >> 16) & 0xff;
int y = (full >> 8) & 0xff;
int x = full & 0xff;
outBuf[index++] = (byte) (0xf0 | (z >> 5));
outBuf[index++] = (byte) (0x80 | ((z << 4) & 0x30) | (y >> 4));
outBuf[index++] = (byte) (0x80 | ((y << 2) & 0x3c) | (x >> 6));
outBuf[index++] = (byte) (0x80 | (x & 0x3f));
i++; // char has been consumed
}
}
}
out.write(outBuf, 0, index);
start = end;
}
}
/**
* Reads the specified number of bytes from the {@link InputStream}.
*
* @param byteLength number of bytes to read
* @return byte array containing the bytes read or null if
* there is an {@link IOException} or if the requested number of bytes
* cannot be read from the {@link InputStream}
*/
private static byte[] readBytesFromInputStream(InputStream input,
int byteLength) {
try {
byte[] bytes = new byte[byteLength];
int byteOffset = 0;
while (byteOffset < byteLength) {
int bytesReadCount = input.read(bytes, byteOffset, byteLength
- byteOffset);
if (bytesReadCount == -1) {
return null;
}
byteOffset += bytesReadCount;
}
return bytes;
} catch (IOException e) {
// Ignored.
}
return null;
}
/**
* Creates a string from the bytes using the specified character set name.
*
* @param bytes bytes to convert
* @param charsetName the name of the character set to use
*
* @return String for the given bytes and character set or null
* if the character set is not supported
*/
private static String toString(byte[] bytes, String charsetName) {
try {
return new String(bytes, charsetName);
} catch (UnsupportedEncodingException e) {
// Ignored.
}
return null;
}
private static void writeAttribute(PrintWriter w, Attr attr, int depth)
throws IOException {
w.write(attr.getName());
w.write('=');
Node c = attr.getFirstChild();
while (c != null) {
w.write('"');
writeNode(w, c, depth);
w.write('"');
c = c.getNextSibling();
}
}
private static void writeDocument(PrintWriter w, Document d)
throws IOException {
w.println("");
Node c = d.getFirstChild();
while (c != null) {
writeNode(w, c, 0);
c = c.getNextSibling();
}
}
private static void writeElement(PrintWriter w, Element el, int depth)
throws IOException {
String tagName = el.getTagName();
writeIndent(w, depth);
w.write('<');
w.write(tagName);
NamedNodeMap attrs = el.getAttributes();
for (int i = 0, n = attrs.getLength(); i < n; ++i) {
w.write(' ');
writeNode(w, attrs.item(i), depth);
}
Node c = el.getFirstChild();
if (c != null) {
// There is at least one child.
//
w.println('>');
// Write the children.
//
while (c != null) {
writeNode(w, c, depth + 1);
w.println();
c = c.getNextSibling();
}
// Write the closing tag.
//
writeIndent(w, depth);
w.write("');
} else {
// There are no children, so just write the short form close.
//
w.print("/>");
}
}
private static void writeIndent(PrintWriter w, int depth) {
for (int i = 0; i < depth; ++i) {
w.write('\t');
}
}
private static void writeNode(PrintWriter w, Node node, int depth)
throws IOException {
short nodeType = node.getNodeType();
switch (nodeType) {
case Node.ELEMENT_NODE:
writeElement(w, (Element) node, depth);
break;
case Node.ATTRIBUTE_NODE:
writeAttribute(w, (Attr) node, depth);
break;
case Node.DOCUMENT_NODE:
writeDocument(w, (Document) node);
break;
case Node.TEXT_NODE:
writeText(w, (Text) node);
break;
case Node.COMMENT_NODE:
case Node.CDATA_SECTION_NODE:
case Node.ENTITY_REFERENCE_NODE:
case Node.ENTITY_NODE:
case Node.PROCESSING_INSTRUCTION_NODE:
default:
throw new RuntimeException("Unsupported DOM node type: " + nodeType);
}
}
private static void writeText(PrintWriter w, Text text) throws DOMException {
String nodeValue = text.getNodeValue();
String escaped = escapeXml(nodeValue);
w.write(escaped);
}
/**
* Not instantiable.
*/
private Util() {
}
}