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

所有已实现的接口:
Aware, BeanFactoryAware, BeanNameAware, BeanFactoryPostProcessor, Ordered, PriorityOrdered
直接已知子类:
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:
```
   
 
```
从以下版本开始:
3.1
作者:
Chris Beams, Juergen Hoeller
另请参阅:
PropertyPlaceholderConfigurer, PropertySourcesPlaceholderConfigurer

字段概要

字段
修饰符和类型	字段	说明
`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 ":"

从类继承的字段 org.springframework.core.io.support.PropertiesLoaderSupport
localOverride, localProperties, logger

从接口继承的字段 org.springframework.core.Ordered
HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

构造器概要
构造器
构造器说明
PlaceholderConfigurerSupport()

方法概要

所有方法实例方法具体方法
修饰符和类型	方法	说明
`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. "" (empty String) or "null".
`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.

从类继承的方法 org.springframework.beans.factory.config.PropertyResourceConfigurer
convertProperties, convertProperty, convertPropertyValue, getOrder, postProcessBeanFactory, processProperties, setOrder

从类继承的方法 org.springframework.core.io.support.PropertiesLoaderSupport
loadProperties, mergeProperties, setFileEncoding, setIgnoreResourceNotFound, setLocalOverride, setLocation, setLocations, setProperties, setPropertiesArray, setPropertiesPersister

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - DEFAULT_PLACEHOLDER_PREFIX
```
public static final String DEFAULT_PLACEHOLDER_PREFIX
```
    Default placeholder prefix: "${"
    另请参阅:
    常量字段值
  - DEFAULT_PLACEHOLDER_SUFFIX
```
public static final String DEFAULT_PLACEHOLDER_SUFFIX
```
    Default placeholder suffix: "}"
    另请参阅:
    常量字段值
  - DEFAULT_VALUE_SEPARATOR
```
public static final String DEFAULT_VALUE_SEPARATOR
```
    Default value separator: ":"
    另请参阅:
    常量字段值
  - placeholderPrefix
```
protected String placeholderPrefix
```
    Defaults to "${"
  - placeholderSuffix
```
protected String placeholderSuffix
```
    Defaults to "}"
  - valueSeparator
```
protected String valueSeparator
```
    Defaults to ":"
  - trimValues
```
protected boolean trimValues
```
  - nullValue
```
protected String nullValue
```
  - ignoreUnresolvablePlaceholders
```
protected boolean ignoreUnresolvablePlaceholders
```
- 构造器详细资料
  - PlaceholderConfigurerSupport
```
public PlaceholderConfigurerSupport()
```
- 方法详细资料
  - 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.
    从以下版本开始:
    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.
    指定者:
    setBeanName 在接口中 BeanNameAware
    参数:
    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.
    另请参阅:
    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.
    指定者:
    setBeanFactory 在接口中 BeanFactoryAware
    参数:
    beanFactory - owning BeanFactory (never null). The bean can immediately call methods on the factory.
    另请参阅:
    PropertiesLoaderSupport.setLocations(org.springframework.core.io.Resource...), ResourceEditor
  - doProcessProperties
```
protected void doProcessProperties(ConfigurableListableBeanFactory beanFactoryToProcess,
                                   StringValueResolver valueResolver)
```

类 PlaceholderConfigurerSupport

字段概要

从类继承的字段 org.springframework.core.io.support.PropertiesLoaderSupport

从接口继承的字段 org.springframework.core.Ordered

构造器概要

方法概要

从类继承的方法 org.springframework.beans.factory.config.PropertyResourceConfigurer

从类继承的方法 org.springframework.core.io.support.PropertiesLoaderSupport

从类继承的方法 java.lang.Object

字段详细资料

DEFAULT_PLACEHOLDER_PREFIX

DEFAULT_PLACEHOLDER_SUFFIX

DEFAULT_VALUE_SEPARATOR

placeholderPrefix

placeholderSuffix

valueSeparator

trimValues

nullValue

ignoreUnresolvablePlaceholders

构造器详细资料

PlaceholderConfigurerSupport

方法详细资料

setPlaceholderPrefix

setPlaceholderSuffix

setValueSeparator

setTrimValues

setNullValue

setIgnoreUnresolvablePlaceholders

setBeanName

setBeanFactory

doProcessProperties