com.baidu.disconf.client.addons.properties

Class DefaultPropertyPlaceholderConfigurer

java.lang.Object

org.springframework.core.io.support.PropertiesLoaderSupport

org.springframework.beans.factory.config.PropertyResourceConfigurer

org.springframework.beans.factory.config.PlaceholderConfigurerSupport

org.springframework.beans.factory.config.PropertyPlaceholderConfigurer

com.baidu.disconf.client.addons.properties.DefaultPropertyPlaceholderConfigurer

All Implemented Interfaces:

org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanFactoryAware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.config.BeanFactoryPostProcessor, org.springframework.core.Ordered, org.springframework.core.PriorityOrdered

Direct Known Subclasses:

ReloadingPropertyPlaceholderConfigurer

public class DefaultPropertyPlaceholderConfigurer
extends org.springframework.beans.factory.config.PropertyPlaceholderConfigurer

A property resource configurer that resolves placeholders with defaults in bean property values of context definitions. It pulls values from a properties file into bean definitions, using the default value if no value is given in the properties file.

The default syntax uses an equals sign ('=') to separate the placeholder name from the default value. This syntax mimicks the syntax which would be used in a property file.

Example:

 <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
   <property name="driverClassName" value="${driver=com.mysql.jdbc.Driver}"/>
   <property name="url" value="jdbc:${dbname=mysql:mydb}"/>
 </bean>

Having a default value directly inside the bean definition file, at the place where the property is set, avoids redundantly listing the placeholder names. It is most useful for properties that usually keep their default value and are rarely customized outside the bean definition file.

The lookup order for properties and locations is exactly as described in PropertyPlaceholderConfigurer. The default value is only used if none of the specified properties and locations contains a value for the placeholder. If no default value is specified, this class behaves exactly the same as its superclass.

See Also:

PropertyPlaceholderConfigurer, setDefaultSeparator(java.lang.String)

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_DEFAULT_SEPARATOR

Fields inherited from class org.springframework.beans.factory.config.PropertyPlaceholderConfigurer

SYSTEM_PROPERTIES_MODE_FALLBACK, SYSTEM_PROPERTIES_MODE_NEVER, SYSTEM_PROPERTIES_MODE_OVERRIDE

Fields inherited from class org.springframework.beans.factory.config.PlaceholderConfigurerSupport

DEFAULT_PLACEHOLDER_PREFIX, DEFAULT_PLACEHOLDER_SUFFIX, DEFAULT_VALUE_SEPARATOR, ignoreUnresolvablePlaceholders, nullValue, placeholderPrefix, placeholderSuffix, valueSeparator

Fields inherited from class org.springframework.core.io.support.PropertiesLoaderSupport

localOverride, localProperties, logger

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
DefaultPropertyPlaceholderConfigurer()

Method Summary

Methods

Modifier and Type	Method and Description
protected String	getDefault(String placeholderWithDefault) extract the default value from the complete placeholder (the part between separator and suffix).
protected String	getPlaceholder(String placeholderWithDefault) extract the placeholder name from the complete placeholder string (between prefix and separator, or complete placeholder if no separator is found).
protected String	resolvePlaceholder(String placeholderWithDefault, Properties props, int systemPropertiesMode)
void	setDefaultSeparator(String def) Set the string that separates a placeholder name from the default value.

Methods inherited from class org.springframework.beans.factory.config.PropertyPlaceholderConfigurer

parseStringValue, processProperties, resolvePlaceholder, resolveSystemProperty, setSearchSystemEnvironment, setSystemPropertiesMode, setSystemPropertiesModeName

Methods inherited from class org.springframework.beans.factory.config.PlaceholderConfigurerSupport

doProcessProperties, setBeanFactory, setBeanName, setIgnoreUnresolvablePlaceholders, setNullValue, setPlaceholderPrefix, setPlaceholderSuffix, setValueSeparator

Methods inherited from class org.springframework.beans.factory.config.PropertyResourceConfigurer

convertProperties, convertProperty, convertPropertyValue, getOrder, postProcessBeanFactory, setOrder

Methods inherited from class org.springframework.core.io.support.PropertiesLoaderSupport

loadProperties, mergeProperties, setFileEncoding, setIgnoreResourceNotFound, setLocalOverride, setLocation, setLocations, setProperties, setPropertiesArray, setPropertiesPersister

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_DEFAULT_SEPARATOR

public static final String DEFAULT_DEFAULT_SEPARATOR

See Also:

Constant Field Values

Constructor Detail

DefaultPropertyPlaceholderConfigurer

public DefaultPropertyPlaceholderConfigurer()

Method Detail

setDefaultSeparator

public final void setDefaultSeparator(String def)

Set the string that separates a placeholder name from the default value. The default is "=".

Parameters:

def - separator

See Also:

DEFAULT_DEFAULT_SEPARATOR

resolvePlaceholder

protected final String resolvePlaceholder(String placeholderWithDefault,
                        Properties props,
                        int systemPropertiesMode)

Overrides:

resolvePlaceholder in class org.springframework.beans.factory.config.PropertyPlaceholderConfigurer

Parameters:

placeholderWithDefault - default placeholder

props - properties instance

systemPropertiesMode - system properties mode

Returns:

the resolved placeholder

getPlaceholder

protected final String getPlaceholder(String placeholderWithDefault)

extract the placeholder name from the complete placeholder string (between prefix and separator, or complete placeholder if no separator is found).

Parameters:

placeholderWithDefault - default placeholder

Returns:

the placeholder

See Also:

PlaceholderConfigurerSupport.setPlaceholderPrefix(java.lang.String), setDefaultSeparator(java.lang.String), PlaceholderConfigurerSupport.setPlaceholderSuffix(java.lang.String)

getDefault

protected final String getDefault(String placeholderWithDefault)

extract the default value from the complete placeholder (the part between separator and suffix).

Parameters:

placeholderWithDefault -

Returns:

the default value, or null if none is given.

See Also:

PlaceholderConfigurerSupport.setPlaceholderPrefix(java.lang.String), setDefaultSeparator(java.lang.String), PlaceholderConfigurerSupport.setPlaceholderSuffix(java.lang.String)