co.codewizards.cloudstore.core.util

Class PropertiesUtil

java.lang.Object

co.codewizards.cloudstore.core.util.PropertiesUtil

public final class PropertiesUtil
extends Object

Properties utilities.

Author:

Marc Klinger - marc[at]nightlabs[dot]de, Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de

Field Summary

Fields

Modifier and Type	Field and Description
static String	SUFFIX_NULL_VALUE Suffix appended to the real property-key to store the boolean flag whether the real property represents the null value.

Method Summary

Methods

Modifier and Type	Method and Description
static Map<String,String>	filterProperties(Map<?,?> rawProperties) Filter the given raw properties.
static Map<String,String>	filterProperties(Map<?,?> rawProperties, Map<?,?> variables) Filter the given raw properties.
static String	getMetaPropertyKeyNullValue(String key) Get the null-indicating meta-property's key for the given real property's key.
static Properties	getProperties(Properties properties, String keyPrefix) Get all properties whose keys start with the given prefix.
static Collection<Matcher>	getPropertyKeyMatches(Properties properties, Pattern pattern) Get all matches where property keys match the given pattern.
static String	getReferencedPropertyKeyForMetaPropertyKey(String key) Get the referenced property-key for the given meta-property's key.
static int	getSystemPropertyValueAsInt(String key, int defaultValue)
static long	getSystemPropertyValueAsLong(String key, long defaultValue)
static boolean	isMetaPropertyKey(String key) Determine, if the given property-key is a meta-property for another property.
static boolean	isMetaPropertyKeyNullValue(String key) Determine, if the given property-key is a null-indicating meta-property for another property.
static boolean	isNullValue(Map<?,?> properties, String key) Determine, if the property identified by the given key has a null-value.
static Properties	load(File file)
static Properties	load(String filename)
static void	putAll(Properties source, Properties target)
static void	store(File file, Properties properties, String comment)
static void	store(String filename, Properties properties, String comment)

Methods inherited from class java.lang.Object

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

Field Detail

SUFFIX_NULL_VALUE

public static final String SUFFIX_NULL_VALUE

Suffix appended to the real property-key to store the boolean flag whether the real property represents the null value.

It is not possible to store a null value in a Properties instance (and neither it is in a properties file). But sometimes it is necessary to explicitly formulate a null value, for example when overriding a property in a way as if it had not been specified in the overridden properties.

For example, let there be these properties declared in a persistence unit:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.TransactionType = JTA
 javax.persistence.jtaDataSource = jdbc/someDataSource
 javax.persistence.transactionType = JTA
 

If the transaction type is to be overridden by "RESOURCE_LOCAL", this is straight-forward:

 javax.jdo.option.TransactionType = RESOURCE_LOCAL
 javax.persistence.transactionType = RESOURCE_LOCAL
 

But to override the datasource properties to be null, is not possible by simply writing "javax.jdo.option.ConnectionFactoryName = = " as this would be interpreted as empty string. Therefore it is possible to declare the null value using an additional key:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.ConnectionFactoryName.null = true
 javax.persistence.jtaDataSource.null = true
 

It is not necessary to quote the referenced key as shown in the 2nd example ("javax.persistence.jtaDataSource" is not present). However, if it is present ("javax.jdo.option.ConnectionFactoryName" above), the null-indicating meta-property "javax.jdo.option.ConnectionFactoryName.null" overrides the value "jdbc/someDataSource".

See Also:

getMetaPropertyKeyNullValue(String), filterProperties(Map, Map), Constant Field Values

Method Detail

getPropertyKeyMatches

public static Collection<Matcher> getPropertyKeyMatches(Properties properties,
                                        Pattern pattern)

Get all matches where property keys match the given pattern.

Parameters:

properties - The properties to match

pattern - The pattern to match against

Returns:

The Matchers that matched.

getProperties

public static Properties getProperties(Properties properties,
                       String keyPrefix)

Get all properties whose keys start with the given prefix.

The returned property elements have the form (key,value) where key is the part of the original key after the given keyPrefix and value is the original value.

Parameters:

properties - The properties to filter.

keyPrefix - The kex prefix to use

Returns:

the properties that start with the given prefix

putAll

public static void putAll(Properties source,
          Properties target)

load

public static Properties load(String filename)
                       throws IOException

Throws:

IOException

load

public static Properties load(File file)
                       throws IOException

Throws:

IOException

store

public static void store(String filename,
         Properties properties,
         String comment)
                  throws IOException

Throws:

IOException

store

public static void store(File file,
         Properties properties,
         String comment)
                  throws IOException

Throws:

IOException

filterProperties

public static Map<String,String> filterProperties(Map<?,?> rawProperties)

Filter the given raw properties.

This is a convenience method delegating to filterProperties(Map, Map) with variables == null.

Parameters:

rawProperties - the properties to be filtered; must not be null.

Returns:

the filtered properties.

See Also:

filterProperties(Map, Map)

filterProperties

public static Map<String,String> filterProperties(Map<?,?> rawProperties,
                                  Map<?,?> variables)

Filter the given raw properties.

Replace null-meta-data to null values: Every property for which the method isNullValue(Map, String) returns true is written with a null value into the result-map. Every property for which the method isMetaPropertyKeyNullValue(String) returns true, is ignored (i.e. does not occur in the result-map).

It is not possible to store a null value in a Properties instance (and neither it is in a properties file). But sometimes it is necessary to explicitly formulate a null value, for example when overriding a property in a way as if it had not been specified in the overridden properties.

For example, let there be these properties declared in a persistence unit:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.TransactionType = JTA
 javax.persistence.jtaDataSource = jdbc/someDataSource
 javax.persistence.transactionType = JTA
 

If the transaction type is to be overridden by "RESOURCE_LOCAL", this is straight-forward:

 javax.jdo.option.TransactionType = RESOURCE_LOCAL
 javax.persistence.transactionType = RESOURCE_LOCAL
 

But to override the datasource properties to be null, is not possible by simply writing "javax.jdo.option.ConnectionFactoryName = = " as this would be interpreted as empty string. Therefore it is possible to declare the null value using an additional key:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.ConnectionFactoryName.null = true
 javax.persistence.jtaDataSource.null = true
 

It is not necessary to quote the referenced key as shown in the 2nd example ("javax.persistence.jtaDataSource" is not present). However, if it is present ("javax.jdo.option.ConnectionFactoryName" above), the null-indicating meta-property "javax.jdo.option.ConnectionFactoryName.null" overrides the value "jdbc/someDataSource".

Replace template variables: If the optional variables argument is present, every value is filtered using IOUtil.replaceTemplateVariables(String, Map).

For example, let there be these properties:

 some.url1 = file:/tmp/myTempDir
 some.url2 = http://host.domain.tld/tomcat
 

If this method is called with System.getProperties() as variables and the user "marco" is currently working on a linux machine, the resulting Map will contain the following resolved properties:

 some.url1 = file:/tmp/myTempDir
 some.url2 = http://host.domain.tld/marco
 

Parameters:

rawProperties - the properties to be filtered; must not be null.

variables - optional template variables; if present, every value is filtered using IOUtil.replaceTemplateVariables(String, Map).

Returns:

the filtered properties.

isMetaPropertyKeyNullValue

public static boolean isMetaPropertyKeyNullValue(String key)

Determine, if the given property-key is a null-indicating meta-property for another property.

It is not possible to store a null value in a Properties instance (and neither it is in a properties file). But sometimes it is necessary to explicitly formulate a null value, for example when overriding a property in a way as if it had not been specified in the overridden properties.

For example, let there be these properties declared in a persistence unit:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.TransactionType = JTA
 javax.persistence.jtaDataSource = jdbc/someDataSource
 javax.persistence.transactionType = JTA
 

If the transaction type is to be overridden by "RESOURCE_LOCAL", this is straight-forward:

 javax.jdo.option.TransactionType = RESOURCE_LOCAL
 javax.persistence.transactionType = RESOURCE_LOCAL
 

But to override the datasource properties to be null, is not possible by simply writing "javax.jdo.option.ConnectionFactoryName = = " as this would be interpreted as empty string. Therefore it is possible to declare the null value using an additional key:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.ConnectionFactoryName.null = true
 javax.persistence.jtaDataSource.null = true
 

It is not necessary to quote the referenced key as shown in the 2nd example ("javax.persistence.jtaDataSource" is not present). However, if it is present ("javax.jdo.option.ConnectionFactoryName" above), the null-indicating meta-property "javax.jdo.option.ConnectionFactoryName.null" overrides the value "jdbc/someDataSource".

Parameters:

key - the property-key to check.

Returns:

true, if the given key references a property that is a null-indicating meta-property for another property.

See Also:

isMetaPropertyKey(String)

isMetaPropertyKey

public static boolean isMetaPropertyKey(String key)

Determine, if the given property-key is a meta-property for another property.

Currently, this is equivalent to isMetaPropertyKeyNullValue(String), but other meta-properties might be introduced later.

Parameters:

key - the property-key to check.

Returns:

true, if the given key references a property that is a meta-property for another property.

getReferencedPropertyKeyForMetaPropertyKey

public static String getReferencedPropertyKeyForMetaPropertyKey(String key)

Get the referenced property-key for the given meta-property's key.

Parameters:

key - a meta-property's key - for example the null-indicating property-key "some.prop.null".

Returns:

the referenced property-key - for example "some.prop".

See Also:

SUFFIX_NULL_VALUE, getMetaPropertyKeyNullValue(String)

getMetaPropertyKeyNullValue

public static String getMetaPropertyKeyNullValue(String key)

Get the null-indicating meta-property's key for the given real property's key.

Parameters:

key - a property-key - for example "some.prop".

Returns:

the null-indicating meta-property's key - for example "some.prop.null".

See Also:

SUFFIX_NULL_VALUE, getReferencedPropertyKeyForMetaPropertyKey(String)

isNullValue

public static boolean isNullValue(Map<?,?> properties,
                  String key)

Determine, if the property identified by the given key has a null-value.

It is not possible to store a null value in a Properties instance (and neither it is in a properties file). But sometimes it is necessary to explicitly formulate a null value, for example when overriding a property in a way as if it had not been specified in the overridden properties.

For example, let there be these properties declared in a persistence unit:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.TransactionType = JTA
 javax.persistence.jtaDataSource = jdbc/someDataSource
 javax.persistence.transactionType = JTA
 

If the transaction type is to be overridden by "RESOURCE_LOCAL", this is straight-forward:

 javax.jdo.option.TransactionType = RESOURCE_LOCAL
 javax.persistence.transactionType = RESOURCE_LOCAL
 

But to override the datasource properties to be null, is not possible by simply writing "javax.jdo.option.ConnectionFactoryName = = " as this would be interpreted as empty string. Therefore it is possible to declare the null value using an additional key:

 javax.jdo.option.ConnectionFactoryName = jdbc/someDataSource
 javax.jdo.option.ConnectionFactoryName.null = true
 javax.persistence.jtaDataSource.null = true
 

It is not necessary to quote the referenced key as shown in the 2nd example ("javax.persistence.jtaDataSource" is not present). However, if it is present ("javax.jdo.option.ConnectionFactoryName" above), the null-indicating meta-property "javax.jdo.option.ConnectionFactoryName.null" overrides the value "jdbc/someDataSource".

Parameters:

properties - the properties. Must not be null.

key - the property-key for which to determine, whether its value is null.

Returns:

true, if the property referenced by the given key is null; false otherwise.

getSystemPropertyValueAsInt

public static int getSystemPropertyValueAsInt(String key,
                              int defaultValue)

getSystemPropertyValueAsLong

public static long getSystemPropertyValueAsLong(String key,
                                long defaultValue)