/*****************************************************************
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.cayenne.util;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.lang.reflect.Member;
import java.lang.reflect.Modifier;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.apache.cayenne.Cayenne;
import org.apache.cayenne.PersistenceState;
import org.apache.cayenne.Persistent;
import org.apache.cayenne.di.spi.DefaultAdhocObjectFactory;
import org.apache.cayenne.reflect.ArcProperty;
import org.apache.cayenne.reflect.AttributeProperty;
import org.apache.cayenne.reflect.PropertyVisitor;
import org.apache.cayenne.reflect.ToManyProperty;
import org.apache.cayenne.reflect.ToOneProperty;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
/**
* Contains various unorganized static utility methods used across Cayenne.
*/
public class Util {
private static DefaultAdhocObjectFactory objectFactory;
static {
objectFactory = new DefaultAdhocObjectFactory();
}
/**
* Converts URL to file. Throws {@link IllegalArgumentException} if the URL is not a
* "file://" URL.
*/
public static File toFile(URL url) throws IllegalArgumentException {
// must convert spaces to %20, or URL->URI conversion may fail
String urlString = url.toExternalForm();
URI uri;
try {
uri = new URI(urlString.replace(" ", "%20"));
}
catch (URISyntaxException e) {
throw new IllegalArgumentException("URL "
+ urlString
+ " can't be converted to URI", e);
}
return new File(uri);
}
/**
* Reads file contents, returning it as a String, using System default line separator.
*/
public static String stringFromFile(File file) throws IOException {
return stringFromFile(file, System.getProperty("line.separator"));
}
/**
* Reads file contents, returning it as a String, joining lines with provided
* separator.
*/
public static String stringFromFile(File file, String joinWith) throws IOException {
StringBuilder buf = new StringBuilder();
BufferedReader in = new BufferedReader(new FileReader(file));
try {
String line = null;
while ((line = in.readLine()) != null) {
buf.append(line).append(joinWith);
}
}
finally {
in.close();
}
return buf.toString();
}
/**
* @param strings The list of strings to join.
* @param separator The separator between the strings.
* @return A single string of all the input strings separated by the separator.
*/
public static String join(List<String> strings, String separator) {
if (strings == null || strings.size() == 0)
return "";
if (separator == null)
separator = "";
StringBuilder builder = new StringBuilder();
for (String string : strings) {
if (builder.length() > 0)
builder.append(separator);
builder.append(string);
}
return builder.toString();
}
/**
* Copies file contents from source to destination. Makes up for the lack of file
* copying utilities in Java
*
* @deprecated since 3.1 this method is not used by Cayenne
*/
@Deprecated
public static boolean copy(File source, File destination) {
BufferedInputStream fin = null;
BufferedOutputStream fout = null;
try {
int bufSize = 8 * 1024;
fin = new BufferedInputStream(new FileInputStream(source), bufSize);
fout = new BufferedOutputStream(new FileOutputStream(destination), bufSize);
copyPipe(fin, fout, bufSize);
}
catch (IOException ioex) {
return false;
}
catch (SecurityException sx) {
return false;
}
finally {
if (fin != null) {
try {
fin.close();
}
catch (IOException cioex) {
}
}
if (fout != null) {
try {
fout.close();
}
catch (IOException cioex) {
}
}
}
return true;
}
/**
* Save URL contents to a file.
*
* @deprecated since 3.1 this method is not used by Cayenne.
*/
@Deprecated
public static boolean copy(URL from, File to) {
BufferedInputStream urlin = null;
BufferedOutputStream fout = null;
try {
int bufSize = 8 * 1024;
urlin = new BufferedInputStream(
from.openConnection().getInputStream(),
bufSize);
fout = new BufferedOutputStream(new FileOutputStream(to), bufSize);
copyPipe(urlin, fout, bufSize);
}
catch (IOException ioex) {
return false;
}
catch (SecurityException sx) {
return false;
}
finally {
if (urlin != null) {
try {
urlin.close();
}
catch (IOException cioex) {
}
}
if (fout != null) {
try {
fout.close();
}
catch (IOException cioex) {
}
}
}
return true;
}
/**
* Reads data from the input and writes it to the output, until the end of the input
* stream.
*
* @deprecated since 3.1 this method is unused by Cayenne.
*/
@Deprecated
public static void copyPipe(InputStream in, OutputStream out, int bufSizeHint)
throws IOException {
int read = -1;
byte[] buf = new byte[bufSizeHint];
while ((read = in.read(buf, 0, bufSizeHint)) >= 0) {
out.write(buf, 0, read);
}
out.flush();
}
/**
* Deletes a file or directory, allowing recursive directory deletion. This is an
* improved version of File.delete() method.
*
* @deprecated since 3.1 this method is unused by Cayenne.
*/
@Deprecated
public static boolean delete(String filePath, boolean recursive) {
File file = new File(filePath);
if (!file.exists()) {
return true;
}
if (!recursive || !file.isDirectory())
return file.delete();
String[] contents = file.list();
// list can be null if directory doesn't have an 'x' permission bit set for the
// user
if (contents != null) {
for (String item : contents) {
if (!delete(filePath + File.separator + item, true)) {
return false;
}
}
}
return file.delete();
}
/**
* Replaces all backslashes "\" with forward slashes "/". Convenience method to
* convert path Strings to URI format.
*/
public static String substBackslashes(String string) {
return RegexUtil.substBackslashes(string);
}
/**
* Looks up and returns the root cause of an exception. If none is found, returns
* supplied Throwable object unchanged. If root is found, recursively "unwraps" it,
* and returns the result to the user.
*/
public static Throwable unwindException(Throwable th) {
if (th instanceof SAXException) {
SAXException sax = (SAXException) th;
if (sax.getException() != null) {
return unwindException(sax.getException());
}
}
else if (th instanceof SQLException) {
SQLException sql = (SQLException) th;
if (sql.getNextException() != null) {
return unwindException(sql.getNextException());
}
}
else if (th.getCause() != null) {
return unwindException(th.getCause());
}
return th;
}
/**
* Compares two objects similar to "Object.equals(Object)". Unlike Object.equals(..),
* this method doesn't throw an exception if any of the two objects is null.
*/
public static boolean nullSafeEquals(Object o1, Object o2) {
if (o1 == null) {
return o2 == null;
}
// Arrays must be handled differently since equals() only does
// an "==" for an array and ignores equivalence. If an array, use
// the Jakarta Commons Language component EqualsBuilder to determine
// the types contained in the array and do individual comparisons.
if (o1.getClass().isArray()) {
EqualsBuilder builder = new EqualsBuilder();
builder.append(o1, o2);
return builder.isEquals();
}
else { // It is NOT an array, so use regular equals()
return o1.equals(o2);
}
}
/**
* Compares two objects similar to "Comparable.compareTo(Object)". Unlike
* Comparable.compareTo(..), this method doesn't throw an exception if any of the two
* objects is null.
*
* @since 1.1
*/
public static <T> int nullSafeCompare(boolean nullsFirst, Comparable<T> o1, T o2) {
if (o1 == null && o2 == null) {
return 0;
}
else if (o1 == null) {
return nullsFirst ? -1 : 1;
}
else if (o2 == null) {
return nullsFirst ? 1 : -1;
}
else {
return o1.compareTo(o2);
}
}
/**
* Returns true, if the String is null or an empty string.
*/
public static boolean isEmptyString(String string) {
return string == null || string.length() == 0;
}
/**
* Creates Serializable object copy using serialization/deserialization.
*/
public static <T extends Serializable> T cloneViaSerialization(T object)
throws Exception {
ByteArrayOutputStream bytes = new ByteArrayOutputStream() {
@Override
public byte[] toByteArray() {
return buf;
}
};
ObjectOutputStream out = new ObjectOutputStream(bytes);
out.writeObject(object);
out.close();
ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(bytes
.toByteArray()));
T copy = (T) in.readObject();
// no need to close the stream - we created it and now will be throwing away...
// in.close();
return copy;
}
/**
* Creates an XMLReader with default feature set. Note that all Cayenne internal XML
* parsers should probably use XMLReader obtained via this method for consistency
* sake, and can customize feature sets as needed.
*/
public static XMLReader createXmlReader() throws SAXException,
ParserConfigurationException {
SAXParserFactory spf = SAXParserFactory.newInstance();
// Create a JAXP SAXParser
SAXParser saxParser = spf.newSAXParser();
// Get the encapsulated SAX XMLReader
XMLReader reader = saxParser.getXMLReader();
// set default features
reader.setFeature("http://xml.org/sax/features/namespaces", true);
return reader;
}
/**
* Returns package name for the Java class as a path separated with forward slash
* ("/"). Method is used to lookup resources that are located in package
* subdirectories. For example, a String "a/b/c" will be returned for class name
* "a.b.c.ClassName".
*/
public static String getPackagePath(String className) {
return RegexUtil.getPackagePath(className);
}
/**
* Returns an unqualified class name for the fully qualified name.
*
* @since 3.0
*/
public static String stripPackageName(String className) {
if (className == null || className.length() == 0)
return className;
int lastDot = className.lastIndexOf('.');
if ((-1 == lastDot) || ((className.length() - 1) == lastDot))
return className;
return className.substring(lastDot + 1);
}
/**
* Creates a mutable map out of two arrays with keys and values.
*
* @since 1.2
*/
public static <K, V> Map<K, V> toMap(K[] keys, V[] values) {
int keysSize = (keys != null) ? keys.length : 0;
int valuesSize = (values != null) ? values.length : 0;
if (keysSize == 0 && valuesSize == 0) {
// return mutable map
return new HashMap<K, V>();
}
if (keysSize != valuesSize) {
throw new IllegalArgumentException(
"The number of keys doesn't match the number of values.");
}
Map<K, V> map = new HashMap<K, V>();
for (int i = 0; i < keysSize; i++) {
map.put(keys[i], values[i]);
}
return map;
}
/**
* Extracts extension from the file name. Dot is not included in the returned string.
*/
public static String extractFileExtension(String fileName) {
int dotInd = fileName.lastIndexOf('.');
// if dot is in the first position,
// we are dealing with a hidden file rather than an extension
return (dotInd > 0 && dotInd < fileName.length()) ? fileName
.substring(dotInd + 1) : null;
}
/**
* Strips extension from the file name.
*/
public static String stripFileExtension(String fileName) {
int dotInd = fileName.lastIndexOf('.');
// if dot is in the first position,
// we are dealing with a hidden file rather than an extension
return (dotInd > 0) ? fileName.substring(0, dotInd) : fileName;
}
/**
* @deprecated since 3.1 in favor of {@link #stripLineBreaks(String, char)}.
* @since 1.2
*/
@Deprecated
public static String stripLineBreaks(String string, String replaceWith) {
if (isEmptyString(string)) {
return string;
}
int len = string.length();
StringBuilder buffer = new StringBuilder(len);
for (int i = 0; i < len; i++) {
char c = string.charAt(i);
// skip \n, \r, \r\n
switch (c) {
case '\n':
case '\r': // do lookahead
if (i + 1 < len && string.charAt(i + 1) == '\n') {
i++;
}
buffer.append(replaceWith);
break;
default:
buffer.append(c);
}
}
return buffer.toString();
}
/**
* Strips "\n", "\r\n", "\r" from the argument string, replacing them with a provided
* character.
*
* @since 3.1
*/
public static String stripLineBreaks(String string, char replaceWith) {
if (string == null) {
return null;
}
int len = string.length();
char[] buffer = new char[len];
boolean matched = false;
int j = 0;
for (int i = 0; i < len; i++, j++) {
char c = string.charAt(i);
// skip \n, \r, \r\n
if (c == '\n' || c == '\r') {
matched = true;
// do lookahead
if (i + 1 < len && string.charAt(i + 1) == '\n') {
i++;
}
buffer[j] = replaceWith;
}
else {
buffer[j] = c;
}
}
return matched ? new String(buffer, 0, j) : string;
}
/**
* Encodes a string so that it can be used as an attribute value in an XML document.
* Will do conversion of the greater/less signs, quotes and ampersands.
*/
public static String encodeXmlAttribute(String string) {
if (string == null) {
return null;
}
int len = string.length();
if (len == 0) {
return string;
}
StringBuilder encoded = new StringBuilder();
for (int i = 0; i < len; i++) {
char c = string.charAt(i);
if (c == '<')
encoded.append("<");
else if (c == '\"')
encoded.append(""");
else if (c == '>')
encoded.append(">");
else if (c == '\'')
encoded.append("'");
else if (c == '&')
encoded.append("&");
else
encoded.append(c);
}
return encoded.toString();
}
/**
* Trims long strings substituting middle part with "...".
*
* @param str String to trim.
* @param maxLength maximum allowable length. Must be at least 5, or an
* IllegalArgumentException is thrown.
* @return String
*/
public static String prettyTrim(String str, int maxLength) {
if (maxLength < 5) {
throw new IllegalArgumentException(
"Algorithm for 'prettyTrim' works only with length >= 5. "
+ "Supplied length is "
+ maxLength);
}
if (str == null || str.length() <= maxLength) {
return str;
}
// find a section to cut off
int len = maxLength - 3;
int startLen = len / 2;
int endLen = len - startLen;
return str.substring(0, startLen) + "..." + str.substring(str.length() - endLen);
}
/**
* Returns a sorted iterator from an unsorted one. Use this method as a last resort,
* since it is much less efficient then just sorting a collection that backs the
* original iterator.
*/
public static <T> Iterator<T> sortedIterator(Iterator<T> it, Comparator<T> comparator) {
List<T> list = new ArrayList<T>();
while (it.hasNext()) {
list.add(it.next());
}
Collections.sort(list, comparator);
return list.iterator();
}
/**
* Builds a hashCode of Collection.
*/
public static int hashCode(Collection<?> c) {
HashCodeBuilder builder = new HashCodeBuilder();
for (Object o : c) {
builder.append(o);
}
return builder.toHashCode();
}
/**
* @since 1.2
*/
public static Pattern sqlPatternToPattern(String pattern, boolean ignoreCase) {
String preprocessed = RegexUtil.sqlPatternToRegex(pattern);
int flag = (ignoreCase) ? Pattern.CASE_INSENSITIVE : 0;
return Pattern.compile(preprocessed, flag);
}
/**
* Returns true if a Member is accessible via reflection under normal Java access
* controls.
*
* @since 1.2
*/
public static boolean isAccessible(Member member) {
return Modifier.isPublic(member.getModifiers())
&& Modifier.isPublic(member.getDeclaringClass().getModifiers());
}
/**
* Creates a Java class, handling regular class names as well as single-dimensional
* arrays and primitive types.
*
* @since 1.2
*/
public static Class<?> getJavaClass(String className) throws ClassNotFoundException {
return objectFactory.getJavaClass(className);
}
static void setReverse(
final Persistent sourceObject,
String propertyName,
final Persistent targetObject) {
ArcProperty property = (ArcProperty) Cayenne
.getClassDescriptor(sourceObject)
.getProperty(propertyName);
ArcProperty reverseArc = property.getComplimentaryReverseArc();
if (reverseArc != null) {
reverseArc.visit(new PropertyVisitor() {
public boolean visitToMany(ToManyProperty property) {
property.addTargetDirectly(targetObject, sourceObject);
return false;
}
public boolean visitToOne(ToOneProperty property) {
property.setTarget(targetObject, sourceObject, false);
return false;
}
public boolean visitAttribute(AttributeProperty property) {
return false;
}
});
sourceObject.getObjectContext().getGraphManager().arcCreated(
targetObject.getObjectId(),
sourceObject.getObjectId(),
reverseArc.getName());
markAsDirty(targetObject);
}
}
static void unsetReverse(
final Persistent sourceObject,
String propertyName,
final Persistent targetObject) {
ArcProperty property = (ArcProperty) Cayenne
.getClassDescriptor(sourceObject)
.getProperty(propertyName);
ArcProperty reverseArc = property.getComplimentaryReverseArc();
if (reverseArc != null) {
reverseArc.visit(new PropertyVisitor() {
public boolean visitToMany(ToManyProperty property) {
property.removeTargetDirectly(targetObject, sourceObject);
return false;
}
public boolean visitToOne(ToOneProperty property) {
property.setTarget(targetObject, null, false);
return false;
}
public boolean visitAttribute(AttributeProperty property) {
return false;
}
});
sourceObject.getObjectContext().getGraphManager().arcDeleted(
targetObject.getObjectId(),
sourceObject.getObjectId(),
reverseArc.getName());
markAsDirty(targetObject);
}
}
/**
* Changes object state to MODIFIED if needed, returning true if the change has
* occurred, false if not.
*/
static boolean markAsDirty(Persistent object) {
if (object.getPersistenceState() == PersistenceState.COMMITTED) {
object.setPersistenceState(PersistenceState.MODIFIED);
return true;
}
return false;
}
}