java.lang.Object
- org.springframework.core.io.support.PropertiesLoaderSupport
- - org.springframework.beans.factory.config.PropertyResourceConfigurer
  - - org.springframework.beans.factory.config.PlaceholderConfigurerSupport

All Implemented Interfaces:
Aware, BeanFactoryAware, BeanNameAware, BeanFactoryPostProcessor, Ordered, PriorityOrdered
Direct Known Subclasses:
PropertyPlaceholderConfigurer, PropertySourcesPlaceholderConfigurer
```
public abstract class PlaceholderConfigurerSupport
extends PropertyResourceConfigurer
implements BeanNameAware, BeanFactoryAware
```
Abstract base class for property resource configurers that resolve placeholders in bean definition property values. Implementations pull values from a properties file or other property source into bean definitions.
The default placeholder syntax follows the Ant / Log4J / JSP EL style:
```
${...}
```
Example XML bean definition:
```
 
   
   
 
 
```
Example properties file:
```
driver=com.mysql.jdbc.Driver
 dbname=mysql:mydb
```
Annotated bean definitions may take advantage of property replacement using the @Value annotation:
```
@Value("${person.age}")
```
Implementations check simple property values, lists, maps, props, and bean names in bean references. Furthermore, placeholder values can also cross-reference other placeholders, like:
```
rootPath=myrootdir
 subPath=${rootPath}/subdir
```
In contrast to PropertyOverrideConfigurer, subclasses of this type allow filling in of explicit placeholders in bean definitions.
If a configurer cannot resolve a placeholder, a BeanDefinitionStoreException will be thrown. If you want to check against multiple properties files, specify multiple resources via the locations property. You can also define multiple configurers, each with its own placeholder syntax. Use ignoreUnresolvablePlaceholders to intentionally suppress throwing an exception if a placeholder cannot be resolved.
Default property values can be defined globally for each configurer instance via the properties property, or on a property-by-property basis using the default value separator which is ":" by default and customizable via setValueSeparator(String).
Example XML property with default value:
```
   
 
```
Since:
3.1
Author:
Chris Beams, Juergen Hoeller
See Also:
PropertyPlaceholderConfigurer, PropertySourcesPlaceholderConfigurer

Field Summary

Fields
Modifier and Type	Field	Description
`static String`	`DEFAULT_PLACEHOLDER_PREFIX`	Default placeholder prefix: "${"
`static String`	`DEFAULT_PLACEHOLDER_SUFFIX`	Default placeholder suffix: "}"
`static String`	`DEFAULT_VALUE_SEPARATOR`	Default value separator: ":"
`protected boolean`	`ignoreUnresolvablePlaceholders`
`protected String`	`nullValue`
`protected String`	`placeholderPrefix`	Defaults to "${"
`protected String`	`placeholderSuffix`	Defaults to "}"
`protected boolean`	`trimValues`
`protected String`	`valueSeparator`	Defaults to ":"

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 Description
PlaceholderConfigurerSupport()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`doProcessProperties(ConfigurableListableBeanFactory beanFactoryToProcess, StringValueResolver valueResolver)`
`void`	`setBeanFactory(BeanFactory beanFactory)`	Only necessary to check that we're not parsing our own bean definition, to avoid failing on unresolvable placeholders in properties file locations.
`void`	`setBeanName(String beanName)`	Only necessary to check that we're not parsing our own bean definition, to avoid failing on unresolvable placeholders in properties file locations.
`void`	`setIgnoreUnresolvablePlaceholders(boolean ignoreUnresolvablePlaceholders)`	Set whether to ignore unresolvable placeholders.
`void`	`setNullValue(String nullValue)`	Set a value that should be treated as `null` when resolved as a placeholder value: e.g.
`void`	`setPlaceholderPrefix(String placeholderPrefix)`	Set the prefix that a placeholder string starts with.
`void`	`setPlaceholderSuffix(String placeholderSuffix)`	Set the suffix that a placeholder string ends with.
`void`	`setTrimValues(boolean trimValues)`	Specify whether to trim resolved values before applying them, removing superfluous whitespace from the beginning and end.
`void`	`setValueSeparator(String valueSeparator)`	Specify the separating character between the placeholder variable and the associated default value, or `null` if no such special character should be processed as a value separator.

Methods inherited from class org.springframework.beans.factory.config.PropertyResourceConfigurer
convertProperties, convertProperty, convertPropertyValue, getOrder, postProcessBeanFactory, processProperties, 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_PLACEHOLDER_PREFIX
```
public static final String DEFAULT_PLACEHOLDER_PREFIX
```
    Default placeholder prefix: "${"
    See Also:
    Constant Field Values
  - DEFAULT_PLACEHOLDER_SUFFIX
```
public static final String DEFAULT_PLACEHOLDER_SUFFIX
```
    Default placeholder suffix: "}"
    See Also:
    Constant Field Values
  - DEFAULT_VALUE_SEPARATOR
```
public static final String DEFAULT_VALUE_SEPARATOR
```
    Default value separator: ":"
    See Also:
    Constant Field Values
  - placeholderPrefix
```
protected String placeholderPrefix
```
    Defaults to "${"
  - placeholderSuffix
```
protected String placeholderSuffix
```
    Defaults to "}"
  - valueSeparator
```
protected String valueSeparator
```
    Defaults to ":"
  - trimValues
```
protected boolean trimValues
```
  - nullValue
```
protected String nullValue
```
  - ignoreUnresolvablePlaceholders
```
protected boolean ignoreUnresolvablePlaceholders
```
- Constructor Detail
  - PlaceholderConfigurerSupport
```
public PlaceholderConfigurerSupport()
```
- Method Detail
  - setPlaceholderPrefix
```
public void setPlaceholderPrefix(String placeholderPrefix)
```
    Set the prefix that a placeholder string starts with. The default is "${".
  - setPlaceholderSuffix
```
public void setPlaceholderSuffix(String placeholderSuffix)
```
    Set the suffix that a placeholder string ends with. The default is "}".
  - setValueSeparator
```
public void setValueSeparator(String valueSeparator)
```
    Specify the separating character between the placeholder variable and the associated default value, or null if no such special character should be processed as a value separator. The default is ":".
  - setTrimValues
```
public void setTrimValues(boolean trimValues)
```
    Specify whether to trim resolved values before applying them, removing superfluous whitespace from the beginning and end.
    Default is false.
    Since:
    4.3
  - setNullValue
```
public void setNullValue(String nullValue)
```
    Set a value that should be treated as null when resolved as a placeholder value: e.g. "" (empty String) or "null".
    Note that this will only apply to full property values, not to parts of concatenated values.
    By default, no such null value is defined. This means that there is no way to express null as a property value unless you explicitly map a corresponding value here.
  - setIgnoreUnresolvablePlaceholders
```
public void setIgnoreUnresolvablePlaceholders(boolean ignoreUnresolvablePlaceholders)
```
    Set whether to ignore unresolvable placeholders.
    Default is "false": An exception will be thrown if a placeholder fails to resolve. Switch this flag to "true" in order to preserve the placeholder String as-is in such a case, leaving it up to other placeholder configurers to resolve it.
  - setBeanName
```
public void setBeanName(String beanName)
```
    Only necessary to check that we're not parsing our own bean definition, to avoid failing on unresolvable placeholders in properties file locations. The latter case can happen with placeholders for system properties in resource locations.
    Specified by:
    setBeanName in interface BeanNameAware
    Parameters:
    beanName - the name of the bean in the factory. Note that this name is the actual bean name used in the factory, which may differ from the originally specified name: in particular for inner bean names, the actual bean name might have been made unique through appending "#..." suffixes. Use the BeanFactoryUtils.originalBeanName(String) method to extract the original bean name (without suffix), if desired.
    See Also:
    PropertiesLoaderSupport.setLocations(org.springframework.core.io.Resource...), ResourceEditor
  - setBeanFactory
```
public void setBeanFactory(BeanFactory beanFactory)
```
    Only necessary to check that we're not parsing our own bean definition, to avoid failing on unresolvable placeholders in properties file locations. The latter case can happen with placeholders for system properties in resource locations.
    Specified by:
    setBeanFactory in interface BeanFactoryAware
    Parameters:
    beanFactory - owning BeanFactory (never null). The bean can immediately call methods on the factory.
    See Also:
    PropertiesLoaderSupport.setLocations(org.springframework.core.io.Resource...), ResourceEditor
  - doProcessProperties
```
protected void doProcessProperties(ConfigurableListableBeanFactory beanFactoryToProcess,
                                   StringValueResolver valueResolver)
```

Class PlaceholderConfigurerSupport

Field Summary

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

Fields inherited from interface org.springframework.core.Ordered

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_PLACEHOLDER_PREFIX

DEFAULT_PLACEHOLDER_SUFFIX

DEFAULT_VALUE_SEPARATOR

placeholderPrefix

placeholderSuffix

valueSeparator

trimValues

nullValue

ignoreUnresolvablePlaceholders

Constructor Detail

PlaceholderConfigurerSupport

Method Detail

setPlaceholderPrefix

setPlaceholderSuffix

setValueSeparator

setTrimValues

setNullValue

setIgnoreUnresolvablePlaceholders

setBeanName

setBeanFactory

doProcessProperties