de.cismet.cids.utils

Class ClassloadingHelper

java.lang.Object

de.cismet.cids.utils.ClassloadingHelper

public class ClassloadingHelper
extends Object

Utility class that is mainly used to load classes of the various special cids ClassloadingHelper.CLASS_TYPEs for a MetaClass. The procedure to load a specific class is the following:

1. From a name that was specified by a System.getProperty(java.lang.String)
2. From candidate names produced by #getClassNames(Sirius.server.middleware.types.MetaClass, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE, java.lang.String) for the domain of the MetaClass
3. From candidate names produced by #getClassNames(Sirius.server.middleware.types.MetaClass, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE, java.lang.String) for the alternative domains defined by the CL_PROP_ALT_DOMAINS property

Version:

1.2

Author:

stefan, mscholl

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ClassloadingHelper.CLASS_TYPE Class types of the extension points supported by the cids system.
static class	ClassloadingHelper.DOM_CTYPE_ORDER Allowed domain classtype order directives.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CL_PROP_ALT_DOMAINS The property 'classloading.alternativeDomains' which can be used to specify alternative classloading domains.
static String	CL_PROP_DOM_CTYPE_ORDER The property 'classloading.domainClassTypeOrder' which can be used to specify the desired order during candidate class name build.
static String	CL_PROPERTIES A property file 'classloading.properties' that may contain configurations concerning classloading.

Method Summary

Modifier and Type	Method and Description
static String	camelize(String toCamelize) Camelises a given string.
static String	capitalize(String toCapitalize) Capitalises a given string.
static String	getClassNameByConfiguration(MemberAttributeInfo mai, ClassloadingHelper.CLASS_TYPE classType) Loads the candidate class name from configuration according to the cids extension points.
static String	getClassNameByConfiguration(MetaClass metaClass, ClassloadingHelper.CLASS_TYPE classType) Loads the candidate class name from configuration according to the cids extension points.
static String	getClassNameByConfiguration(MetaClass metaClass, MemberAttributeInfo mai, ClassloadingHelper.CLASS_TYPE classType) Deprecated. support will most likely be dropped
static List<String>	getClassNames(MetaClass metaClass, ClassloadingHelper.CLASS_TYPE classType) Produces candidate class names for a given MetaClass and ClassloadingHelper.CLASS_TYPE.
static List<String>	getClassNames(MetaClass metaClass, ClassloadingHelper.CLASS_TYPE classType, String forDomain, ClassloadingHelper.DOM_CTYPE_ORDER order) Produces candidate names for a given MetaClass, CLASS_TYPE, domain and order.
static List<String>	getClassNames(MetaClass metaClass, MemberAttributeInfo mai, ClassloadingHelper.CLASS_TYPE classType) Deprecated. support will most likely be dropped
static Class<?>	getDynamicClass(MetaClass metaClass, ClassloadingHelper.CLASS_TYPE classType) Loads a Class object for the given MetaClass of the given CLASS_TYPE by first receiving a list of candidate names from getClassNames(Sirius.server.middleware.types.MetaClass, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE) and then using loadClassFromCandidates(java.util.List).
static Class<?>	getDynamicClass(MetaClass metaClass, MemberAttributeInfo mai, ClassloadingHelper.CLASS_TYPE classType) Deprecated. support will most likely be dropped
static Class<?>	loadClassFromCandidates(List<String> candidateClassNames) Loads a Class from candidate names.

Methods inherited from class java.lang.Object

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

Field Detail

CL_PROPERTIES

public static final String CL_PROPERTIES

A property file 'classloading.properties' that may contain configurations concerning classloading. It shall be placed in a package with the following name:

<packagePrefix provided by a ClassLoadingPackagePrefixProvider>.<domain of the MetaClass>

Example:
DefaultClassLoadingPackagePrefixProvider -> prefix= de.cismet.cids.custom
MetaClass -> domain= MY_DOMAIN

property file expected here -> de.cismet.cids.custom.my_domain.classloading.properties

See Also:

ClassLoadingPackagePrefixProvider, StringUtils.toPackage(java.lang.String), Constant Field Values

CL_PROP_ALT_DOMAINS

public static final String CL_PROP_ALT_DOMAINS

The property 'classloading.alternativeDomains' which can be used to specify alternative classloading domains. Its value is expected to be csv. The property must be defined in a CL_PROPERTIES file if it shall be used by the ClassloadingHelper to create candidate names.

See Also:

Constant Field Values

CL_PROP_DOM_CTYPE_ORDER

public static final String CL_PROP_DOM_CTYPE_ORDER

The property 'classloading.domainClassTypeOrder' which can be used to specify the desired order during candidate class name build. Valid values are:

• default (classtype only) )
• classtype (classtype first only, default)
• domain (domain first only)
• both-classtype (both, classtype first)
• both-domain (both, domain first)

The property must be defined in a CL_PROPERTIES file if it shall be used by the ClassloadingHelper to create candidate names.

See Also:

Constant Field Values

Method Detail

getClassNames

public static List<String> getClassNames(MetaClass metaClass,
                                         MemberAttributeInfo mai,
                                         ClassloadingHelper.CLASS_TYPE classType)

Deprecated. support will most likely be dropped

DOCUMENT ME!

Parameters:

metaClass - DOCUMENT ME!

mai - DOCUMENT ME!

classType - DOCUMENT ME!

Returns:

DOCUMENT ME!

capitalize

public static String capitalize(String toCapitalize)

Capitalises a given string. The result of will be an all lowercase string except for an uppercase first letter, e.g. fOo_BAR -> Foo_bar.

Parameters:

toCapitalize - the string to capitalise

Returns:

an all lowercase string except for an uppercase first letter

getClassNames

public static List<String> getClassNames(MetaClass metaClass,
                                         ClassloadingHelper.CLASS_TYPE classType)

Produces candidate class names for a given MetaClass and ClassloadingHelper.CLASS_TYPE. It first produces candidate class names from the domain of the MetaClass using getClassNames(Sirius.server.middleware.types.MetaClass, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE, java.lang.String, de.cismet.cids.utils.ClassloadingHelper.DOM_CTYPE_ORDER) with the order defined by CL_PROP_DOM_CTYPE_ORDER. After that it iterates through the alternative domains defined by CL_PROP_ALT_DOMAINS (if any).

Parameters:

metaClass - the MetaClass to create candidate class names for

classType - the CLASS_TYPE to create candidate class names for

Returns:

a list of candidate class names

See Also:

getClassNames(Sirius.server.middleware.types.MetaClass,de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE, java.lang.String, de.cismet.cids.utils.ClassloadingHelper.DOM_CTYPE_ORDER)

getClassNames

public static List<String> getClassNames(MetaClass metaClass,
                                         ClassloadingHelper.CLASS_TYPE classType,
                                         String forDomain,
                                         ClassloadingHelper.DOM_CTYPE_ORDER order)

Produces candidate names for a given MetaClass, CLASS_TYPE, domain and order. The procedure to create candidate names is the following:

1. Use name specified by a System.getProperty(java.lang.String)
2. Iterate through the available package prefixes and create candidate names using buildCandidateNames(java.lang.String, java.lang.String, java.lang.String, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE, de.cismet.cids.utils.ClassloadingHelper.DOM_CTYPE_ORDER)
3. Use getClassNameByConfiguration(Sirius.server.middleware.types.MetaClass, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE)

The system property that can be used to specify a candidate name is build with the following pattern:

<domain>.<tableName>.<ClassloadingHelper.CLASS_TYPE.overrideProperty>

NOTE: The domain name is converted to a proper package name first using StringUtils.toPackage(java.lang.String).

IMPORTANT: Currently the order does not properly follow the 'convention over configuration' rules!

Parameters:

metaClass - the MetaClass to create candidate class names for

classType - the CLASS_TYPE to create candidate class names for

forDomain - the domain to create candidate class names for

order - the order that shall be applied

Returns:

a list of candidate class names

See Also:

ClassLoadingPackagePrefixProvider, StringUtils.toPackage(java.lang.String)

getClassNameByConfiguration

public static String getClassNameByConfiguration(MetaClass metaClass,
                                                 ClassloadingHelper.CLASS_TYPE classType)

Loads the candidate class name from configuration according to the cids extension points.

Parameters:

metaClass - the MetaClass to get the configuration for

classType - the specific CLASS_TYPE to get the configuration for

Returns:

the configured class name (which can be null) or null if the given classType is not recognised

getClassNameByConfiguration

public static String getClassNameByConfiguration(MemberAttributeInfo mai,
                                                 ClassloadingHelper.CLASS_TYPE classType)

Loads the candidate class name from configuration according to the cids extension points.

Parameters:

mai - the MemberAttributeInfo to get the configuration for

classType - the specific CLASS_TYPE to get the configuration for

Returns:

the configured class name (which can be null) or null if the given classType is not recognised

getClassNameByConfiguration

public static String getClassNameByConfiguration(MetaClass metaClass,
                                                 MemberAttributeInfo mai,
                                                 ClassloadingHelper.CLASS_TYPE classType)

Deprecated. support will most likely be dropped

DOCUMENT ME!

Parameters:

metaClass - DOCUMENT ME!

mai - DOCUMENT ME!

classType - DOCUMENT ME!

Returns:

DOCUMENT ME!

camelize

public static String camelize(String toCamelize)

Camelises a given string. It ignores all non-letters and non-digits. However, the very first character and every character following an ignored one will be uppercase. The rest will be lowercase, e.g. fOo_bAr -> FooBar

Parameters:

toCamelize - the string to camelise

Returns:

the camelised string

loadClassFromCandidates

public static Class<?> loadClassFromCandidates(List<String> candidateClassNames)

Loads a Class from candidate names. The result of the first successful try will be returned.

Parameters:

candidateClassNames - a list of class names that shall be tried

Returns:

a fully initialised Class object of the first successful try or null if none of the candidate names could be used to load the class

getDynamicClass

public static Class<?> getDynamicClass(MetaClass metaClass,
                                       MemberAttributeInfo mai,
                                       ClassloadingHelper.CLASS_TYPE classType)

Deprecated. support will most likely be dropped

DOCUMENT ME!

Parameters:

metaClass - DOCUMENT ME!

mai - DOCUMENT ME!

classType - DOCUMENT ME!

Returns:

DOCUMENT ME!

getDynamicClass

public static Class<?> getDynamicClass(MetaClass metaClass,
                                       ClassloadingHelper.CLASS_TYPE classType)

Loads a Class object for the given MetaClass of the given CLASS_TYPE by first receiving a list of candidate names from getClassNames(Sirius.server.middleware.types.MetaClass, de.cismet.cids.utils.ClassloadingHelper.CLASS_TYPE) and then using loadClassFromCandidates(java.util.List).

Parameters:

metaClass - the MetaClass to load a Class object of the given CLASS_TYPE for

classType - the requested CLASS_TYPE to load

Returns:

a fully initialsed Class of requested type or null if no class of the given type for the given MetaClass could be found

Throws:

IllegalArgumentException - if metaClass or classType is null