org.apache.cayenne.util
Class Util

java.lang.Object
  org.apache.cayenne.util.Util

public class Util
extends java.lang.Object

Contains various unorganized static utility methods used across Cayenne.

Author:

Andrei Adamchik

Constructor Summary

Util()

Method Summary

static java.lang.Object	cloneViaSerialization(java.io.Serializable obj) Creates Serializable object copy using serialization/deserialization.
static boolean	copy(java.io.File source, java.io.File destination) Copies file contents from source to destination.
static boolean	copy(java.net.URL from, java.io.File to) Save URL contents to a file.
static void	copyPipe(java.io.InputStream in, java.io.OutputStream out, int bufSizeHint) Reads data from the input and writes it to the output, until the end of the input stream.
static org.xml.sax.XMLReader	createXmlReader() Creates an XMLReader with default feature set.
static boolean	delete(java.lang.String filePath, boolean recursive) Deletes a file or directory, allowing recursive directory deletion.
static java.lang.String	encodeXmlAttribute(java.lang.String str) Encodes a string so that it can be used as an attribute value in an XML document.
static java.lang.String	extractFileExtension(java.lang.String fileName) Extracts extension from the file name.
static java.lang.Class	getJavaClass(java.lang.String className) Creates a Java class, handling regular class names as well as single-dimensional arrays and primitive types.
static java.lang.String	getPackagePath(java.lang.String className) Returns package name for the Java class as a path separated with forward slash ("/").
static int	hashCode(java.util.Collection c) Builds a hashCode of Collection.
static boolean	isAccessible(java.lang.reflect.Member member) Returns true if a Member is accessible via reflection under normal Java access controls.
static boolean	isEmptyString(java.lang.String string) Returns true, if the String is null or an empty string.
static int	nullSafeCompare(boolean nullsFirst, java.lang.Comparable o1, java.lang.Object o2) Compares two objects similar to "Comparable.compareTo(Object)".
static boolean	nullSafeEquals(java.lang.Object o1, java.lang.Object o2) Compares two objects similar to "Object.equals(Object)".
static java.lang.String	prettyTrim(java.lang.String str, int maxLength) Trims long strings substituting middle part with "...".
static java.util.Iterator	sortedIterator(java.util.Iterator it, java.util.Comparator comparator) Returns a sorted iterator from an unsorted one.
static java.util.regex.Pattern	sqlPatternToPattern(java.lang.String pattern, boolean ignoreCase)
static java.lang.String	sqlPatternToRegex(java.lang.String pattern, boolean ignoreCase) Deprecated. since 1.2 use "sqlPatternToPattern".
static java.lang.String	stringFromFile(java.io.File file) Reads file contents, returning it as a String, using System default line separator.
static java.lang.String	stringFromFile(java.io.File file, java.lang.String joinWith) Reads file contents, returning it as a String, joining lines with provided separator.
static java.lang.String	stripFileExtension(java.lang.String fileName) Strips extension from the file name.
static java.lang.String	stripLineBreaks(java.lang.String string, java.lang.String replaceWith) Strips "\n", "\r\n", "\r" from the argument string.
static java.lang.String	substBackslashes(java.lang.String string) Replaces all backslashes "\" with forward slashes "/".
static java.util.Map	toMap(java.lang.Object[] keys, java.lang.Object[] values) Creates a mutable map out of two arrays with keys and values.
static java.lang.Throwable	unwindException(java.lang.Throwable th) Looks up and returns the root cause of an exception.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Util

public Util()

Method Detail

stringFromFile

public static java.lang.String stringFromFile(java.io.File file)
                                       throws java.io.IOException

Reads file contents, returning it as a String, using System default line separator.

Throws:

java.io.IOException

stringFromFile

public static java.lang.String stringFromFile(java.io.File file,
                                              java.lang.String joinWith)
                                       throws java.io.IOException

Reads file contents, returning it as a String, joining lines with provided separator.

Throws:

java.io.IOException

copy

public static boolean copy(java.io.File source,
                           java.io.File destination)

Copies file contents from source to destination. Makes up for the lack of file copying utilities in Java

copy

public static boolean copy(java.net.URL from,
                           java.io.File to)

Save URL contents to a file.

copyPipe

public static void copyPipe(java.io.InputStream in,
                            java.io.OutputStream out,
                            int bufSizeHint)
                     throws java.io.IOException

Reads data from the input and writes it to the output, until the end of the input stream.

Parameters:

in -

out -

bufSizeHint -

Throws:

java.io.IOException

delete

public static boolean delete(java.lang.String filePath,
                             boolean recursive)

Deletes a file or directory, allowing recursive directory deletion. This is an improved version of File.delete() method.

substBackslashes

public static java.lang.String substBackslashes(java.lang.String string)

Replaces all backslashes "\" with forward slashes "/". Convenience method to convert path Strings to URI format.

unwindException

public static java.lang.Throwable unwindException(java.lang.Throwable th)

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.

nullSafeEquals

public static boolean nullSafeEquals(java.lang.Object o1,
                                     java.lang.Object o2)

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.

nullSafeCompare

public static int nullSafeCompare(boolean nullsFirst,
                                  java.lang.Comparable o1,
                                  java.lang.Object 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

isEmptyString

public static boolean isEmptyString(java.lang.String string)

Returns true, if the String is null or an empty string.

cloneViaSerialization

public static java.lang.Object cloneViaSerialization(java.io.Serializable obj)
                                              throws java.lang.Exception

Creates Serializable object copy using serialization/deserialization.

Throws:

java.lang.Exception

createXmlReader

public static org.xml.sax.XMLReader createXmlReader()
                                             throws org.xml.sax.SAXException,
                                                    javax.xml.parsers.ParserConfigurationException

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.

Throws:

org.xml.sax.SAXException

javax.xml.parsers.ParserConfigurationException

getPackagePath

public static java.lang.String getPackagePath(java.lang.String className)

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".

toMap

public static java.util.Map toMap(java.lang.Object[] keys,
                                  java.lang.Object[] values)

Creates a mutable map out of two arrays with keys and values.

Since:

1.2

extractFileExtension

public static java.lang.String extractFileExtension(java.lang.String fileName)

Extracts extension from the file name. Dot is not included in the returned string.

stripFileExtension

public static java.lang.String stripFileExtension(java.lang.String fileName)

Strips extension from the file name.

stripLineBreaks

public static java.lang.String stripLineBreaks(java.lang.String string,
                                               java.lang.String replaceWith)

Strips "\n", "\r\n", "\r" from the argument string.

Since:

1.2

encodeXmlAttribute

public static java.lang.String encodeXmlAttribute(java.lang.String str)

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.

prettyTrim

public static java.lang.String prettyTrim(java.lang.String str,
                                          int maxLength)

Trims long strings substituting middle part with "...".

Parameters:

str - String to trim.

maxLength - maximum allowable length. Must be at least 5, or an IllegalArgumentException is thrown.

Returns:

String

sortedIterator

public static java.util.Iterator sortedIterator(java.util.Iterator it,
                                                java.util.Comparator comparator)

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.

hashCode

public static int hashCode(java.util.Collection c)

Builds a hashCode of Collection.

sqlPatternToRegex

public static java.lang.String sqlPatternToRegex(java.lang.String pattern,
                                                 boolean ignoreCase)

Deprecated. since 1.2 use "sqlPatternToPattern".

Converts a SQL-style pattern to a valid Perl regular expression. E.g.:

"billing_%" will become /^billing_.*$/

"user?" will become /^user.?$/

sqlPatternToPattern

public static java.util.regex.Pattern sqlPatternToPattern(java.lang.String pattern,
                                                          boolean ignoreCase)

Since:

1.2

isAccessible

public static boolean isAccessible(java.lang.reflect.Member member)

Returns true if a Member is accessible via reflection under normal Java access controls.

Since:

1.2

getJavaClass

public static java.lang.Class getJavaClass(java.lang.String className)
                                    throws java.lang.ClassNotFoundException

Creates a Java class, handling regular class names as well as single-dimensional arrays and primitive types.

Throws:

java.lang.ClassNotFoundException

Since:

1.2