org.directwebremoting.util
Class LocalUtil

java.lang.Object
  org.directwebremoting.util.LocalUtil

public final class LocalUtil
extends java.lang.Object

Various utilities, stuff that we're still surprised isn't in the JDK, and stuff that perhaps is borderline JDK material, but isn't really pure DWR either. TODO: This probably needs cutting up into

Author:

Joe Walker [joe at getahead dot ltd dot uk]

Method Summary

static void	addNoCacheHeaders(javax.servlet.http.HttpServletResponse resp) Add headers to prevent browsers and proxies from caching this reply.
static java.lang.String	capitalize(java.lang.String input) Changes the first letter to upper case.
static java.lang.Class<?>	classForName(java.lang.String className) Utility to essentially do Class forName and allow configurable Classloaders.
static <T> java.lang.Class<? extends T>	classForName(java.lang.String debugContext, java.lang.String className, java.lang.Class<T> impl) Utility to essentially do Class forName with the assumption that the environment expects failures for missing jar files and can carry on if this process fails.
static <T> T	classNewInstance(java.lang.String name, java.lang.String className, java.lang.Class<T> impl) Utility to essentially do Class forName and newInstance with the assumption that the environment expects failures for missing jar files and can carry on if this process fails.
static void	close(java.io.Closeable in) InputStream closer that can cope if the input stream is null.
static void	close(OutputStreamLoader loader) OutputStreamLoader closer that can cope if the input is null.
static void	debugRequest(javax.servlet.http.HttpServletRequest request) If something has gone wrong we want to know all about the request that caused the failure
static boolean	equals(java.lang.Object object1, java.lang.Object object2) A helper for implementing Object.equals(Object) when some of your members could be null.
static java.lang.reflect.Field[]	getAllFields(java.lang.Class<?> clazz) Return a list of all fields (whatever access status, and on whatever superclass they were defined) that can be found on this class.
static java.util.List<java.lang.Class<?>>	getAllSuperclasses(java.lang.Class<?> clazz) Return a List of super-classes for the given class.
static java.lang.String	getFullUrlToDwrServlet(javax.servlet.http.HttpServletRequest request)
static java.io.InputStream	getInternalResourceAsStream(java.lang.String path) Open a stream to an internal file resource located in the DWR package tree.
static java.lang.reflect.Method	getMethod(java.lang.Class<?> clazz, java.lang.String name, java.lang.Class<?>... args) Utility to retrieve a method.
static java.lang.Class<?>	getNonPrimitiveType(java.lang.Class<?> type)
static <T> T	getProperty(java.lang.Object pojo, java.lang.String propertyName, java.lang.Class<T> type) Utility to find a getter and return it's value from an object If Java had the option to temporarily do dynamic typing there would be no need for this.
static java.lang.Class<?>	getPropertyType(java.lang.Class<?> real, java.lang.String key) Set a property on an object using reflection
static java.net.URL	getResource(java.lang.String path) Open a stream to a file resource located on the classpath.
static java.lang.Throwable	getRootCause(java.lang.Throwable ex) Find the leaf cause of an exception chain.
static long	getSystemClassloadTime() Get a timestamp for the earliest time that we know the JVM started
static java.lang.reflect.Method	getWriteMethod(java.lang.Class<?> clazz, java.beans.PropertyDescriptor property) Obtains the write method for a property.
static boolean	hasLength(java.lang.CharSequence str) Check that the given CharSequence is neither null nor of length 0.
static boolean	hasText(java.lang.CharSequence str) Check whether the given CharSequence has actual text.
static java.lang.String	inferWildcardReplacements(java.lang.String base, java.lang.String wildcarded) Expands wildcards in an identifier string by using information in a base identifier name.
static java.lang.Object	invoke(java.lang.Object object, java.lang.reflect.Method method, java.lang.Object[] params) Calling methods using reflection is useful for graceful fallback - this is a helper method to make this easy
static boolean	isClassNameInDwrOriginalPackage(java.lang.String className) Determines if a classname resides in the DWR original package (org.directwebremoting).
static boolean	isClassNameInDwrRemappedPackage(java.lang.String className) Determines if a classname resides in the remapped package, if applicable.
static boolean	isEquivalent(java.lang.Class<?> c1, java.lang.Class<?> c2) True if c1 is java.lang.Boolean and c2 is boolean, etc.
static boolean	isJavaIdentifier(java.lang.String test) Determines if the specified string is permissible as a Java identifier.
static boolean	isJavaIdentifierWithPackage(java.lang.String test) Determines if the specified string is permissible as a Java identifier potentially prefixed with package names.
static boolean	isJavaScriptTypeAssignableTo(java.lang.String javaScriptType, java.lang.Class<?> clazz) Determines if a JavaScript type is assignable to the passed in Java class.
static boolean	isLetterOrDigitOrUnderline(java.lang.String test) Determines if the specified string contains only Unicode letters or digits as defined by Character.isLetterOrDigit(char)
static boolean	isMeteorAvailable() Is Atmosphere/Meteor present on the classpath?
static boolean	isSafeHierarchicalIdentifierInBrowser(java.lang.String test) Tests if a string contains only characters that will allow safe use inside html element attributes and url:s, and is a valid hierarchical identifier wrt to dot ("package") segments.
static boolean	isSafeIdentifierInBrowser(java.lang.String test) Tests if a string contains only characters that will allow safe use inside html element attributes and url:s.
static boolean	isServletClass(java.lang.Class<?> paramType) Is this class one that we auto fill, so the user can ignore?
static boolean	isSimpleName(java.lang.String name) Is this object property one that we can use in a JSON style or do we need to get fancy.
static boolean	isTypeSimplyConvertable(java.lang.Class<?> paramType) Can the type be used in a call to simpleConvert(String, Class)?
static boolean	isValidMappedClassName(java.lang.String test) Determines whether the supplied string is a valid class name to use for class-mapped data classes.
static boolean	isValidScriptName(java.lang.String test) Determines whether the supplied string is a valid script name to use for remoted classes.
static boolean	isWrapper(java.lang.Object object) Checks if this object is an instance of a primitive wrapper.
static <T> java.lang.Iterable<T>	iterableizer(java.util.Enumeration<?> en, java.lang.Class<T> type) Go Java! Why do I even need to do this?
static <T> java.lang.Iterable<T>	iterableizer(java.util.Enumeration<T> en) Go Java! How many people have written this code?
static java.lang.String	join(java.lang.Object[] array, java.lang.String separator) Create a string by joining the array elements together with the separator in-between each element.
static void	makeAccessible(java.lang.reflect.Constructor<?> ctor) Make the given constructor accessible, explicitly setting it accessible if necessary.
static java.lang.String	originalDwrClassName(java.lang.String className) Converts a remapped DWR classname to the corresponding original name in the org.directwebremoting package.
static java.util.Locale	parseLocaleString(java.lang.String localeString) Parse the given localeString into a Locale.
static java.lang.Class<?>	primitiveToWrapper(java.lang.Class<?> clazz) Converts the specified primitive Class object to its corresponding wrapper Class object.
static java.lang.String	remappedDwrClassName(java.lang.String className) Converts a DWR classname in the original org.directwebremoting package to the corresponding name in the remapped package, if applicable.
static java.lang.String	remappedResourcePath(java.lang.String path) Adjust a resource path to match any remapping done to the DWR package path.
static void	setParams(java.lang.Object object, java.util.Map<java.lang.String,?> params, java.util.List<java.lang.String> ignore) Set use reflection to set the setters on the object called by the keys in the params map with the corresponding values
static void	setProperty(java.lang.Object object, java.lang.String key, java.lang.Object value) Set a property on an object using reflection
static int	shrink(long diff) Comparator.compare(Object, Object) demands that the return is 1, 0, -1.
static <T> T	simpleConvert(java.lang.String value, java.lang.Class<T> paramType) A very simple conversion function for all the IoC style setup and reflection that we are doing.
static java.lang.Class<?>	toClass(java.lang.reflect.Type parameterType, java.lang.String debugContext) Utility to find a Class from a Type if possible, assuming String.class if the conversion can't be made
static java.lang.String	urlDecode(java.lang.String value) URL decode a value.
static java.lang.String	urlEncode(java.lang.String value) URL encode a value.

Methods inherited from class java.lang.Object

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

Method Detail

join

public static java.lang.String join(java.lang.Object[] array,
                                    java.lang.String separator)

Create a string by joining the array elements together with the separator in-between each element. A null (in the array or as a separator) is treated as an empty string.

Parameters:

array - The array of elements to join

separator - The string sequence to place between array elements

Returns:

A string containing the joined elements

hasText

public static boolean hasText(java.lang.CharSequence str)

Check whether the given CharSequence has actual text. More specifically, returns true if the string not null, its length is greater than 0, and it contains at least one non-whitespace character.

 LocalUtil.hasText(null) = false
 LocalUtil.hasText("") = false
 LocalUtil.hasText(" ") = false
 LocalUtil.hasText("12345") = true
 LocalUtil.hasText(" 12345 ") = true
 

Parameters:

str - the CharSequence to check (may be null)

Returns:

true if the CharSequence is not null, its length is greater than 0, and it does not contain whitespace only

See Also:

Character.isWhitespace(char)

hasLength

public static boolean hasLength(java.lang.CharSequence str)

Check that the given CharSequence is neither null nor of length 0. Note: Will return true for a CharSequence that purely consists of whitespace.

 LocalUtil.hasLength(null) = false
 LocalUtil.hasLength("") = false
 LocalUtil.hasLength(" ") = true
 LocalUtil.hasLength("Hello") = true
 

Parameters:

str - the CharSequence to check (may be null)

Returns:

true if the CharSequence is not null and has length

See Also:

hasText(java.lang.CharSequence)

isJavaIdentifier

public static boolean isJavaIdentifier(java.lang.String test)

Determines if the specified string is permissible as a Java identifier. Returns true if the string is non-null, non-zero length with a Java identifier start as the first character and Java identifier parts in all remaining characters.

Parameters:

test - the string to be tested.

Returns:

true if the string is a Java identifier, false otherwise.

See Also:

Character.isJavaIdentifierPart(char), Character.isJavaIdentifierStart(char)

isJavaIdentifierWithPackage

public static boolean isJavaIdentifierWithPackage(java.lang.String test)

Determines if the specified string is permissible as a Java identifier potentially prefixed with package names. It tests each segment of the string separated by "." and returns true if all segments have non-zero length with a Java identifier start as the first character and Java identifier parts in all remaining characters.

Parameters:

test - the string to be tested.

Returns:

true if the string is a Java identifier, false otherwise.

isLetterOrDigitOrUnderline

public static boolean isLetterOrDigitOrUnderline(java.lang.String test)

Determines if the specified string contains only Unicode letters or digits as defined by Character.isLetterOrDigit(char)

Parameters:

test - The string to test

Returns:

true if the string is non-null, non-empty and contains only characters that are unicode letters or digits

See Also:

Character.isLetterOrDigit(char)

isValidScriptName

public static boolean isValidScriptName(java.lang.String test)

Determines whether the supplied string is a valid script name to use for remoted classes.

Parameters:

test -

Returns:

true if the string is a valid script name

isValidMappedClassName

public static boolean isValidMappedClassName(java.lang.String test)

Determines whether the supplied string is a valid class name to use for class-mapped data classes.

Parameters:

test -

Returns:

true if the string is a valid mapped class name

isSafeHierarchicalIdentifierInBrowser

public static boolean isSafeHierarchicalIdentifierInBrowser(java.lang.String test)

Tests if a string contains only characters that will allow safe use inside html element attributes and url:s, and is a valid hierarchical identifier wrt to dot ("package") segments.

Parameters:

test -

Returns:

true if string is safe

isSafeIdentifierInBrowser

public static boolean isSafeIdentifierInBrowser(java.lang.String test)

Tests if a string contains only characters that will allow safe use inside html element attributes and url:s.

Parameters:

test -

Returns:

true if string is safe

inferWildcardReplacements

public static java.lang.String inferWildcardReplacements(java.lang.String base,
                                                         java.lang.String wildcarded)

Expands wildcards in an identifier string by using information in a base identifier name.

Parameters:

base - the base identifier

wildcarded - the wildcarded string to be replaced

Returns:

a string that does not contain * or null

isEquivalent

public static boolean isEquivalent(java.lang.Class<?> c1,
                                   java.lang.Class<?> c2)

True if c1 is java.lang.Boolean and c2 is boolean, etc.

Parameters:

c1 - the first class to test

c2 - the second class to test

Returns:

true if the classes are equivalent

equals

public static boolean equals(java.lang.Object object1,
                             java.lang.Object object2)

A helper for implementing Object.equals(Object) when some of your members could be null. Returns true if both objects are null, or if neither object is null, but object1.equals(object2) returns true. Otherwise returns false.

Parameters:

object1 - The first object to compare.

object2 - The second object to compare.

Returns:

True if the objects are both null or Object.equals(Object)

shrink

public static int shrink(long diff)

Comparator.compare(Object, Object) demands that the return is 1, 0, -1. This helps implement that.

Parameters:

diff - The result of some subtraction.

Returns:

1, 0, -1

getNonPrimitiveType

public static java.lang.Class<?> getNonPrimitiveType(java.lang.Class<?> type)

Parameters:

type - The class to de-primitivize

Returns:

The non-primitive version of the class

addNoCacheHeaders

public static void addNoCacheHeaders(javax.servlet.http.HttpServletResponse resp)

Add headers to prevent browsers and proxies from caching this reply.

Parameters:

resp - The response to add headers to

isServletClass

public static boolean isServletClass(java.lang.Class<?> paramType)

Is this class one that we auto fill, so the user can ignore?

Parameters:

paramType - The type to test

Returns:

true if the type is a Servlet type

getFullUrlToDwrServlet

public static java.lang.String getFullUrlToDwrServlet(javax.servlet.http.HttpServletRequest request)

Parameters:

request -

Returns:

String

debugRequest

public static void debugRequest(javax.servlet.http.HttpServletRequest request)

If something has gone wrong we want to know all about the request that caused the failure

Parameters:

request - The HttpServletRequest the borked

iterableizer

public static <T> java.lang.Iterable<T> iterableizer(java.util.Enumeration<T> en)

Go Java! How many people have written this code?

Parameters:

en - The Enumeration that we want to iterate over

Returns:

An implementation of Iterable for use in a for each loop

iterableizer

public static <T> java.lang.Iterable<T> iterableizer(java.util.Enumeration<?> en,
                                                     java.lang.Class<T> type)

Go Java! Why do I even need to do this?

Parameters:

en - The Enumeration that we want to iterate over

type - For when we were given an Enumeration and need an Iterator

Returns:

An implementation of Iterable for use in a for each loop

urlDecode

public static java.lang.String urlDecode(java.lang.String value)

URL decode a value. URLDecoder.decode(String, String) throws an UnsupportedEncodingException, which is silly given that the most common use case will be to pass in "UTF-8"

Parameters:

value - The string to decode

Returns:

The decoded string

urlEncode

public static java.lang.String urlEncode(java.lang.String value)

URL encode a value. URLEncoder.encode(String, String) throws an UnsupportedEncodingException, which is silly given that the most common use case will be to pass in "UTF-8"

Parameters:

value - The string to decode

Returns:

The decoded string

setParams

public static void setParams(java.lang.Object object,
                             java.util.Map<java.lang.String,?> params,
                             java.util.List<java.lang.String> ignore)

Set use reflection to set the setters on the object called by the keys in the params map with the corresponding values

Parameters:

object - The object to setup

params - The settings to use

ignore - List of keys to not warn about if they are not properties Note only the warning is skipped, we still try the setter

setProperty

public static void setProperty(java.lang.Object object,
                               java.lang.String key,
                               java.lang.Object value)
                        throws java.lang.NoSuchMethodException,
                               java.lang.SecurityException,
                               java.lang.IllegalAccessException,
                               java.lang.IllegalArgumentException,
                               java.lang.reflect.InvocationTargetException

Set a property on an object using reflection

Parameters:

object - The object to call the setter on

key - The name of the property to set.

value - The new value to use for the property

Throws:

java.lang.NoSuchMethodException - Passed on from reflection code

java.lang.SecurityException - Passed on from reflection code

java.lang.IllegalAccessException - Passed on from reflection code

java.lang.IllegalArgumentException - Passed on from reflection code

java.lang.reflect.InvocationTargetException - Passed on from reflection code

isWrapper

public static final boolean isWrapper(java.lang.Object object)

Checks if this object is an instance of a primitive wrapper.

Parameters:

object - anything

Returns:

true if this object is an Integer, Long, Float, Double, Boolean...

getPropertyType

public static java.lang.Class<?> getPropertyType(java.lang.Class<?> real,
                                                 java.lang.String key)

Set a property on an object using reflection

Parameters:

real - The object type to find the setter on

key - The name of the property to set.

isTypeSimplyConvertable

public static boolean isTypeSimplyConvertable(java.lang.Class<?> paramType)

Can the type be used in a call to simpleConvert(String, Class)?

Parameters:

paramType - The type to test

Returns:

true if the type is acceptable to simpleConvert()

simpleConvert

public static <T> T simpleConvert(java.lang.String value,
                                  java.lang.Class<T> paramType)

A very simple conversion function for all the IoC style setup and reflection that we are doing.

Parameters:

value - The value to convert

paramType - The type to convert to. Currently any primitive types and String are supported.

Returns:

The converted object.

isSimpleName

public static boolean isSimpleName(java.lang.String name)

Is this object property one that we can use in a JSON style or do we need to get fancy. i.e does it contain only letters and numbers with an initial letter.

Parameters:

name - The name to test for JSON compatibility

Returns:

true if the name is simple

classForName

public static java.lang.Class<?> classForName(java.lang.String className)
                                       throws java.lang.ClassNotFoundException

Utility to essentially do Class forName and allow configurable Classloaders.

This implementation makes use of the context classloader for the current thread, with fallback to the local classloader if needed.

Parameters:

className - The class to create

Returns:

The class if it is safe or null otherwise.

Throws:

java.lang.ClassNotFoundException - If className is not valid

isMeteorAvailable

public static boolean isMeteorAvailable()

Is Atmosphere/Meteor present on the classpath?

Returns:

boolean

originalDwrClassName

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

Converts a remapped DWR classname to the corresponding original name in the org.directwebremoting package.

Parameters:

className -

Returns:

full class name relative original DWR package

remappedDwrClassName

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

Converts a DWR classname in the original org.directwebremoting package to the corresponding name in the remapped package, if applicable.

Parameters:

className -

Returns:

full class name relative remapped DWR package

isClassNameInDwrOriginalPackage

public static boolean isClassNameInDwrOriginalPackage(java.lang.String className)

Determines if a classname resides in the DWR original package (org.directwebremoting).

Parameters:

className -

Returns:

true if class in original DWR package

isClassNameInDwrRemappedPackage

public static boolean isClassNameInDwrRemappedPackage(java.lang.String className)

Determines if a classname resides in the remapped package, if applicable.

Parameters:

className -

Returns:

true if class in remapped DWR package

classForName

public static <T> java.lang.Class<? extends T> classForName(java.lang.String debugContext,
                                                            java.lang.String className,
                                                            java.lang.Class<T> impl)

Utility to essentially do Class forName with the assumption that the environment expects failures for missing jar files and can carry on if this process fails.

Type Parameters:

T - The base type that we want a class to implement

Parameters:

debugContext - The name for debugging purposes

className - The class to create

impl - The implementation class - what should className do?

Returns:

The class if it is safe or null otherwise.

getMethod

public static java.lang.reflect.Method getMethod(java.lang.Class<?> clazz,
                                                 java.lang.String name,
                                                 java.lang.Class<?>... args)

Utility to retrieve a method.

Parameters:

clazz - - The class where the method exists.

name - - The name of the method to retrieve.

args - - The arguments the method takes.

Returns:

- The method, null if an exception is thrown or clazz is null.

classNewInstance

public static <T> T classNewInstance(java.lang.String name,
                                     java.lang.String className,
                                     java.lang.Class<T> impl)

Utility to essentially do Class forName and newInstance with the assumption that the environment expects failures for missing jar files and can carry on if this process fails.

Type Parameters:

T - The base type that we want a class to implement

Parameters:

name - The name for debugging purposes

className - The class to create

impl - The implementation class - what should className do?

Returns:

The new instance if it is safe or null otherwise.

invoke

public static java.lang.Object invoke(java.lang.Object object,
                                      java.lang.reflect.Method method,
                                      java.lang.Object[] params)
                               throws java.lang.IllegalStateException

Calling methods using reflection is useful for graceful fallback - this is a helper method to make this easy

Parameters:

object - The object to use as 'this'

method - The method to call, can be null in which case null is returned

params - The parameters to pass to the reflection call

Returns:

The results of calling method.invoke() or null

Throws:

java.lang.IllegalStateException - If anything goes wrong

remappedResourcePath

public static java.lang.String remappedResourcePath(java.lang.String path)

Adjust a resource path to match any remapping done to the DWR package path.

Parameters:

path - original resource path

Returns:

path adjusted wrt package remapping

getInternalResourceAsStream

public static java.io.InputStream getInternalResourceAsStream(java.lang.String path)

Open a stream to an internal file resource located in the DWR package tree.

Parameters:

path -

Returns:

an open stream

getResource

public static java.net.URL getResource(java.lang.String path)

Open a stream to a file resource located on the classpath.

Parameters:

path -

Returns:

an open stream

close

public static void close(java.io.Closeable in)

InputStream closer that can cope if the input stream is null. If anything goes wrong, the errors are logged and ignored.

Parameters:

in - The resource to close

close

public static void close(OutputStreamLoader loader)

OutputStreamLoader closer that can cope if the input is null. If anything goes wrong, the errors are logged and ignored.

Parameters:

loader - The resource to close

makeAccessible

public static void makeAccessible(java.lang.reflect.Constructor<?> ctor)

Make the given constructor accessible, explicitly setting it accessible if necessary. The setAccessible(true) method is only called when actually necessary, to avoid unnecessary conflicts with a JVM SecurityManager (if active).

Parameters:

ctor - the constructor to make accessible

See Also:

AccessibleObject.setAccessible(java.lang.reflect.AccessibleObject[], boolean)

getAllSuperclasses

public static java.util.List<java.lang.Class<?>> getAllSuperclasses(java.lang.Class<?> clazz)

Return a List of super-classes for the given class.

Parameters:

clazz - the class to look up

Returns:

the List of super-classes in order going up from this one

getAllFields

public static java.lang.reflect.Field[] getAllFields(java.lang.Class<?> clazz)

Return a list of all fields (whatever access status, and on whatever superclass they were defined) that can be found on this class.

This is like a union of Class.getDeclaredFields() which ignores and super-classes, and Class.getFields() which ignored non-public fields

Parameters:

clazz - The class to introspect

Returns:

The complete list of fields

getProperty

public static <T> T getProperty(java.lang.Object pojo,
                                java.lang.String propertyName,
                                java.lang.Class<T> type)

Utility to find a getter and return it's value from an object If Java had the option to temporarily do dynamic typing there would be no need for this.

Parameters:

pojo - The POJO to extract some data from.

propertyName - The name of the property form which we form a getter name by upper-casing the first letter (in the EN locale) and prefixing with 'get'

Returns:

The value of property, or null if it does not exist

toClass

public static java.lang.Class<?> toClass(java.lang.reflect.Type parameterType,
                                         java.lang.String debugContext)

Utility to find a Class from a Type if possible, assuming String.class if the conversion can't be made

parseLocaleString

public static java.util.Locale parseLocaleString(java.lang.String localeString)

Parse the given localeString into a Locale.

This is the inverse operation of Locale's toString.

Parameters:

localeString - the locale string, following Locale's toString() format ("en", "en_UK", etc); also accepts spaces as separators, as an alternative to underscores

Returns:

a corresponding Locale instance

primitiveToWrapper

public static java.lang.Class<?> primitiveToWrapper(java.lang.Class<?> clazz)

Converts the specified primitive Class object to its corresponding wrapper Class object.

Parameters:

clazz - the class to convert, may be null

Returns:

the wrapper class for cls or cls if cls is not a primitive. null if null input.

capitalize

public static java.lang.String capitalize(java.lang.String input)

Changes the first letter to upper case. No other letters are affected.

Parameters:

input - any

Returns:

any

getWriteMethod

public static java.lang.reflect.Method getWriteMethod(java.lang.Class<?> clazz,
                                                      java.beans.PropertyDescriptor property)

Obtains the write method for a property.

Parameters:

property - any

Returns:

any

isJavaScriptTypeAssignableTo

public static boolean isJavaScriptTypeAssignableTo(java.lang.String javaScriptType,
                                                   java.lang.Class<?> clazz)

Determines if a JavaScript type is assignable to the passed in Java class.

Parameters:

javaScriptType -

clazz -

Returns:

boolean

getSystemClassloadTime

public static long getSystemClassloadTime()

Get a timestamp for the earliest time that we know the JVM started

Returns:

a JVM start time

getRootCause

public static java.lang.Throwable getRootCause(java.lang.Throwable ex)

Find the leaf cause of an exception chain.