更新由Spring注入的属性文件以包含上次运行时间戳 [英] Updating a properties file injected by Spring to include a last run timestamp

问题描述

我有一个使用Spring加载的属性文件的应用程序。然后将Properties实例注入到几个类中。问题是这些属性中的一些被更新 - 例如，我们有一个lastRun时间戳，我们要在这里存储。也许有更好的方法来存储这样的东西（建议欢迎），但我怎么能去更新属性文件？

 < util：properties id =propslocation =some.properties/> 
  

props.store（...）方法需要一个写或输出流（所有我假设是未知的，因为春天处理这个加载）..？

有没有更好的方法，或者我应该从Spring context.xml传递文件路径，并将其发送到各种bean并加载/存储属性文件老式的方式吗？

解决方案

PropertiesFactoryBean没有location属性的访问器，但是你可以从BeanDefinition获得location属性。 / p>

  BeanDefinition def = ctx.getBeanFactory（）。getBeanDefinition（props）; 
 String location = def.getPropertyValues（）。getPropertyValue（location）。getValue（）; 
档案档案= ctx.getResource（location）.getFile（）; 
  

编辑

<包括一个示例类来做到这一点。您可以在bean中定义bean的定义文件，并在适当的地方注入。

  / ** 
 *属性
 * / 
公共类SpringPropertyUpdater实现ApplicationContextAware {
 
 private ConfigurableApplicationContext ctx; 
 private static final String LOCATION_PROPERTY =location; 
 private static final Log log = LogFactory.getLog（SpringPropertyUpdater.class）; 
 $ b / ** 
 *使用新值更新托管属性
 * / 
 public void updateProperties（String name，Properties props，String comments）{
 ConfigurableListableBeanFactory fb = ctx.getBeanFactory（）; 
 BeanDefinition bf = fb.getBeanDefinition（name）; 
 String location =（String）bf.getPropertyValues（）。getPropertyValue（LOCATION_PROPERTY）.getValue（）; 
 Resource res = ctx.getResource（location）; 
尝试{
 File file = res.getFile（）; 
 props.store（new FileOutputStream（file），comments）; 
 catch（IOException e）{
 log.error（e）; 
 
 
 $ b $ ** 
 * {@inheritDoc} 
 * / 
 public void setApplicationContext（ApplicationContext applicationContext）throws BeansException { 
 this.ctx =（ConfigurableApplicationContext）applicationContext; 
 
} 
} 
  

I have an application which makes used of a properties file loaded by Spring. The Properties instance is then injected into a few classes. The question is some of these properties are updated - for example we have a lastRun timestamp which we want to store here. Maybe there is a better way to go about storing something like this (suggestions welcome), but how can I go about updating the properties file?

<util:properties id="props" location="some.properties"/>

The props.store(...) method requires either a write or an output stream (all of which I'm assuming is unknown as Spring handles this loading)..?

Is there a better approach or should I just be passing in the file path from the Spring context.xml and sending it to various beans and loading/storing the properties file the old fashioned way?

解决方案

The PropertiesFactoryBean don't have accessor for location property but you can get the location property from BeanDefinition.

BeanDefinition def = ctx.getBeanFactory().getBeanDefinition("props");
String location = def.getPropertyValues().getPropertyValue("location").getValue();
File file = ctx.getResource(location).getFile();

EDIT

Include a sample class to do it. You can define the bean in bean the definition file and inject where appropiate.

/**
 * Update Spring managed properties
 */
public class SpringPropertyUpdater implements ApplicationContextAware {

    private ConfigurableApplicationContext ctx;
    private static final String LOCATION_PROPERTY = "location";
    private static final Log log = LogFactory.getLog(SpringPropertyUpdater.class);

    /**
     * Update managed properties with new value
     */
    public void  updateProperties(String name, Properties props, String comments) {
        ConfigurableListableBeanFactory fb = ctx.getBeanFactory();
        BeanDefinition bf = fb.getBeanDefinition(name);
        String location = (String) bf.getPropertyValues().getPropertyValue(LOCATION_PROPERTY).getValue();
        Resource res = ctx.getResource(location);
        try {
            File file = res.getFile();
            props.store(new FileOutputStream(file), comments);
        } catch (IOException e) {
            log.error(e);
        }
    }

    /**
     * {@inheritDoc}
     */
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.ctx = (ConfigurableApplicationContext) applicationContext;

    }
}

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