Util (GWT 2.8.2)

java.lang.Object
- com.google.gwt.dev.util.Util

```
public final class Util
extends Object
```
A smattering of useful methods. Methods in this class are candidates for being moved to Utility if they would be generally useful to tool writers, and don't involve TreeLogger.

Field Summary

Fields
Modifier and Type Field and Description

static String DEFAULT_ENCODING

Fields
Modifier and Type	Field and Description
`static String`	`DEFAULT_ENCODING`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`computeStrongName(byte[] content)` Computes the MD5 hash for the specified byte array.
`static String`	`computeStrongName(byte[][] contents)` Computes the MD5 hash of the specified byte arrays.
`static void`	`copy(InputStream is, OutputStream os)`
`static void`	`copy(TreeLogger logger, InputStream is, OutputStream os)` Copies an input stream out to an output stream.
`static void`	`copyNoClose(InputStream is, OutputStream os)` Copies all of the bytes from the input stream to the output stream until the input stream is EOF.
`static Reader`	`createReader(TreeLogger logger, URL url)`
`static boolean`	`equalsNullCheck(Object thisObject, Object thatObject)` Equality check through equals() that is also satisfied if both objects are null.
`static String`	`escapeXml(String unescaped)` Escapes '&', '<', '>', '"', and '\'' to their XML entity equivalents.
`static void`	`escapeXml(String code, int start, int end, boolean quoteApostrophe, StringBuilder builder)` Escapes '&', '<', '>', '"', and optionally ''' to their XML entity equivalents.
`static URL`	`findSourceInClassPath(ClassLoader cl, String sourceTypeName)`
`static byte[]`	`getBytes(String s)` Returns a byte-array representing the default encoding for a String.
`static String`	`getClassName(String className)`
`static String`	`getFileFromInstallPath(String relativePath)` Gets the contents of a file.
`static String`	`getPackageName(String qualifiedName)`
`static long`	`getResourceModifiedTime(URL url)` Retrieves the last modified time of a provided URL.
`static boolean`	`isValidJavaIdent(String token)`
`static File`	`makeRelativeFile(File from, File to)` Attempts to make a path relative to a particular directory.
`static String`	`makeRelativePath(File from, File to)`
`static byte[]`	`readFileAsBytes(File file)`
`static <T extends Serializable> T`	`readFileAsObject(File file, Class<T> type)`
`static String`	`readFileAsString(File file)`
`static byte[]`	`readStreamAsBytes(InputStream in)` Reads an entire input stream as bytes.
`static <T> T`	`readStreamAsObject(InputStream inputStream, Class<T> type)`
`static String`	`readStreamAsString(InputStream in)` Reads an entire input stream as String.
`static byte[]`	`readURLAsBytes(URL url)`
`static char[]`	`readURLAsChars(URL url)`
`static String`	`readURLAsString(URL url)`
`static byte[]`	`readURLConnectionAsBytes(URLConnection connection)`
`static void`	`recursiveDelete(File file, boolean childrenOnly)` Deletes a file or recursively deletes a directory.
`static void`	`recursiveDelete(File file, boolean childrenOnly, FileFilter filter)` Selectively deletes a file or recursively deletes a directory.
`static void`	`releaseThreadLocalBuf(byte[] buf)` Release a buffer previously returned from `takeThreadLocalBuf()`.
`static String`	`stripJarPathPrefix(String absolutePath)` Remove leading file:jar:...!/ prefix from source paths for source located in jars.
`static byte[]`	`takeThreadLocalBuf()` Get a large byte buffer local to this thread.
`static <T> T[]`	`toArray(Class<? super T> componentType, Collection<? extends T> coll)` Creates an array from a collection of the specified component type and size.
`static String`	`toString(byte[] bytes)` Returns a String representing the character content of the bytes; the bytes must be encoded using the compiler's default encoding.
`static File`	`tryMakeCanonical(File file)` Attempts to find the canonical form of a file path.
`static void`	`writeBytesToFile(TreeLogger logger, File where, byte[] what)`
`static void`	`writeBytesToFile(TreeLogger logger, File where, byte[][] what)` Gathering write.
`static void`	`writeObjectAsFile(TreeLogger logger, File file, Object... objects)` Serializes an object and writes it to a file.
`static void`	`writeObjectToStream(OutputStream stream, Object... objects)` Serializes an object and writes it to a stream.
`static boolean`	`writeStringAsFile(File file, String string)`
`static void`	`writeStringAsFile(TreeLogger logger, File file, String string)`
`static void`	`writeUtf8(StringBuilder builder, OutputStream out)` Writes the contents of a StringBuilder to an OutputStream, encoding each character using the UTF-* encoding.

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, toString

- Field Detail
  - DEFAULT_ENCODING
```
public static String DEFAULT_ENCODING
```
- Method Detail
  - computeStrongName
```
public static String computeStrongName(byte[] content)
```
    Computes the MD5 hash for the specified byte array.
    
    Returns:
    
    a big fat string encoding of the MD5 for the content, suitably formatted for use as a file name
  - computeStrongName
```
public static String computeStrongName(byte[][] contents)
```
    Computes the MD5 hash of the specified byte arrays.
    
    Returns:
    
    a big fat string encoding of the MD5 for the content, suitably formatted for use as a file name
  - copy
```
public static void copy(InputStream is,
                        OutputStream os)
                 throws IOException
```
    Throws:
    
    IOException
  - copy
```
public static void copy(TreeLogger logger,
                        InputStream is,
                        OutputStream os)
                 throws UnableToCompleteException
```
    Copies an input stream out to an output stream. Closes the input steam and output stream.
    
    Throws:
    
    UnableToCompleteException
  - copyNoClose
```
public static void copyNoClose(InputStream is,
                               OutputStream os)
                        throws IOException
```
    Copies all of the bytes from the input stream to the output stream until the input stream is EOF. Does not close either stream.
    
    Throws:
    
    IOException
  - createReader
```
public static Reader createReader(TreeLogger logger,
                                  URL url)
                           throws UnableToCompleteException
```
    Throws:
    
    UnableToCompleteException
  - equalsNullCheck
```
public static boolean equalsNullCheck(Object thisObject,
                                      Object thatObject)
```
    Equality check through equals() that is also satisfied if both objects are null.
  - escapeXml
```
public static String escapeXml(String unescaped)
```
    Escapes '&', '<', '>', '"', and '\'' to their XML entity equivalents.
  - escapeXml
```
public static void escapeXml(String code,
                             int start,
                             int end,
                             boolean quoteApostrophe,
                             StringBuilder builder)
```
    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.
    
    Parameters:
    
    code - the input String
    
    start - the first character position to scan.
    
    end - the character position following the last character to scan.
    
    quoteApostrophe - if true, the ' character is quoted as '
    
    builder - a StringBuilder to be appended with the output.
  - findSourceInClassPath
```
public static URL findSourceInClassPath(ClassLoader cl,
                                        String sourceTypeName)
```
  - getBytes
```
public static byte[] getBytes(String s)
```
    Returns a byte-array representing the default encoding for a String.
  - getClassName
```
public static String getClassName(String className)
```
    Parameters:
    
    className - A fully-qualified class name whose name you want.
    
    Returns:
    
    The base name for the specified class.
  - getFileFromInstallPath
```
public static String getFileFromInstallPath(String relativePath)
```
    Gets the contents of a file.
    
    Parameters:
    
    relativePath - relative path within the install directory
    
    Returns:
    
    the contents of the file, or null if an error occurred
  - getPackageName
```
public static String getPackageName(String qualifiedName)
```
    Parameters:
    
    qualifiedName - A fully-qualified class name whose package name you want.
    
    Returns:
    
    The package name for the specified class, empty string if default package.
  - getResourceModifiedTime
```
public static long getResourceModifiedTime(URL url)
```
    Retrieves the last modified time of a provided URL.
    
    Returns:
    
    a positive value indicating milliseconds since the epoch (00:00:00 Jan 1, 1970), or 0L on failure, such as a SecurityException or IOException.
  - isValidJavaIdent
```
public static boolean isValidJavaIdent(String token)
```
  - makeRelativeFile
```
public static File makeRelativeFile(File from,
                                    File to)
```
    Attempts to make a path relative to a particular directory.
    
    Parameters:
    
    from - the directory from which 'to' should be relative
    
    to - an absolute path which will be returned so that it is relative to 'from'
    
    Returns:
    
    the relative path, if possible; null otherwise
  - makeRelativePath
```
public static String makeRelativePath(File from,
                                      File to)
```
  - readFileAsBytes
```
public static byte[] readFileAsBytes(File file)
```
  - readFileAsObject
```
public static <T extends Serializable> T readFileAsObject(File file,
                                                          Class<T> type)
                                                   throws ClassNotFoundException,
                                                          IOException
```
    Throws:
    
    ClassNotFoundException
    
    IOException
  - readFileAsString
```
public static String readFileAsString(File file)
```
  - readStreamAsBytes
```
public static byte[] readStreamAsBytes(InputStream in)
```
    Reads an entire input stream as bytes. Closes the input stream.
  - readStreamAsObject
```
public static <T> T readStreamAsObject(InputStream inputStream,
                                       Class<T> type)
                                throws ClassNotFoundException,
                                       IOException
```
    Throws:
    
    ClassNotFoundException
    
    IOException
  - readStreamAsString
```
public static String readStreamAsString(InputStream in)
```
    Reads an entire input stream as String. Closes the input stream.
  - readURLAsBytes
```
public static byte[] readURLAsBytes(URL url)
```
    Returns:
    
    null if the file could not be read
  - readURLAsChars
```
public static char[] readURLAsChars(URL url)
```
    Returns:
    
    null if the file could not be read
  - readURLAsString
```
public static String readURLAsString(URL url)
```
    Returns:
    
    null if the file could not be read
  - readURLConnectionAsBytes
```
public static byte[] readURLConnectionAsBytes(URLConnection connection)
```
  - recursiveDelete
```
public static void recursiveDelete(File file,
                                   boolean childrenOnly)
```
    Deletes a file or recursively deletes a directory.
    
    Parameters:
    
    file - the file to delete, or if this is a directory, the directory that serves as the root of a recursive deletion
    
    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
  - recursiveDelete
```
public static void recursiveDelete(File file,
                                   boolean childrenOnly,
                                   FileFilter filter)
```
    Selectively deletes a file or recursively deletes a directory. Note that it is possible that files remain if file.delete() fails.
    
    Parameters:
    
    file - the file to delete, or if this is a directory, the directory that serves as the root of a recursive deletion
    
    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
    
    filter - only files matching this filter will be deleted
  - releaseThreadLocalBuf
```
public static void releaseThreadLocalBuf(byte[] buf)
```
    Release a buffer previously returned from takeThreadLocalBuf(). The released buffer may then be reused.
  - stripJarPathPrefix
```
public static String stripJarPathPrefix(String absolutePath)
```
    Remove leading file:jar:...!/ prefix from source paths for source located in jars.
    
    Parameters:
    
    absolutePath - an absolute JAR file URL path
    
    Returns:
    
    the location of the file within the JAR
  - takeThreadLocalBuf
```
public static byte[] takeThreadLocalBuf()
```
    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 releaseThreadLocalBuf(byte[]) on the returned buffer allows subsequent callers to reuse the buffer later, avoiding unncessary allocations and GC.
  - toArray
```
public static <T> T[] toArray(Class<? super T> componentType,
                              Collection<? extends T> coll)
```
    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.
  - toString
```
public static String toString(byte[] bytes)
```
    Returns a String representing the character content of the bytes; the bytes must be encoded using the compiler's default encoding.
  - tryMakeCanonical
```
public static File tryMakeCanonical(File file)
```
    Attempts to find the canonical form of a file path.
    
    Returns:
    
    the canonical version of the file path, if it could be computed; otherwise, the original file is returned unmodified
  - writeBytesToFile
```
public static void writeBytesToFile(TreeLogger logger,
                                    File where,
                                    byte[] what)
                             throws UnableToCompleteException
```
    Throws:
    
    UnableToCompleteException
  - writeBytesToFile
```
public static void writeBytesToFile(TreeLogger logger,
                                    File where,
                                    byte[][] what)
                             throws UnableToCompleteException
```
    Gathering write.
    
    Throws:
    
    UnableToCompleteException
  - writeObjectAsFile
```
public static void writeObjectAsFile(TreeLogger logger,
                                     File file,
                                     Object... objects)
                              throws UnableToCompleteException
```
    Serializes an object and writes it to a file.
    
    Throws:
    
    UnableToCompleteException
  - writeObjectToStream
```
public static void writeObjectToStream(OutputStream stream,
                                       Object... objects)
                                throws IOException
```
    Serializes an object and writes it to a stream.
    
    Throws:
    
    IOException
  - writeStringAsFile
```
public static boolean writeStringAsFile(File file,
                                        String string)
```
  - writeStringAsFile
```
public static void writeStringAsFile(TreeLogger logger,
                                     File file,
                                     String string)
                              throws UnableToCompleteException
```
    Throws:
    
    UnableToCompleteException
  - writeUtf8
```
public static void writeUtf8(StringBuilder builder,
                             OutputStream out)
                      throws IOException
```
    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.
    
    Throws:
    
    IOException

Class Util

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_ENCODING

Method Detail

computeStrongName

computeStrongName

copy

copy

copyNoClose

createReader

equalsNullCheck

escapeXml

escapeXml

findSourceInClassPath

getBytes

getClassName

getFileFromInstallPath

getPackageName

getResourceModifiedTime

isValidJavaIdent

makeRelativeFile

makeRelativePath

readFileAsBytes

readFileAsObject

readFileAsString

readStreamAsBytes

readStreamAsObject

readStreamAsString

readURLAsBytes

readURLAsChars

readURLAsString

readURLConnectionAsBytes

recursiveDelete

recursiveDelete

releaseThreadLocalBuf

stripJarPathPrefix

takeThreadLocalBuf

toArray

toString

tryMakeCanonical

writeBytesToFile

writeBytesToFile

writeObjectAsFile

writeObjectToStream

writeStringAsFile

writeStringAsFile

writeUtf8