如何获取JSF类中资源的句柄? [英] How to get handle to a resource within a JSF class?

问题描述

我已经在我的JSF项目的src/main/resources中放置了一个属性文件.

I've put a properties file within src/main/resources in my JSF project.

如何处理?我知道EL在支持bean中不起作用.

How do I get a handle to it? I understand that EL doesn't work within a backing bean.

注意:该文件位于src/main/resources中-不在src/main/webapps/resources中，因此以下内容不起作用:

Note: The file is in src/main/resources - NOT src/main/webapps/resources, so the following doesn't work:

FacesContext context = FacesContext.getCurrentInstance();
File value = context.getApplication().evaluateExpressionGet(context, "#{resource['resources:email.properties']}", File.class);

推荐答案

因此它位于类路径中.您可以只使用

It's thus in the classpath. You can just use ClassLoader#getResourceAsStream() to get an InputStream out of it. Assuming that src is the classpath root and that main/resources is the package:

InputStream input = Thread.currentThread().getContextClassLoader().getResourceAsStream("main/resources/foo.properties");
Properties properties = new Properties();
properties.load(input);
// ...

或者，如果它是特定于Web应用程序的，因此不应被类路径中具有更高类加载优先级的其他路径(例如，在appserver的lib或JRE的lib中)的同一路径上的文件覆盖，然后使用 ExternalContext#getResourceAsStream() .

Alternatively, if it's supposed to be specific to the webapp and thus isn't supposed to be overrideable by a file on the same path elsewhere in the classpath which has a higher classloading precedence (e.g. in appserver's lib or the JRE's lib), then use ExternalContext#getResourceAsStream() instead.

InputStream input = FacesContext.getCurrentInstance().getExternalContext().getResourceAsStream("main/resources/foo.properties");
Properties properties = new Properties();
properties.load(input);
// ...

对于#{resource}语法，确实确实是针对放置在公共Web内容的/resources文件夹中的CSS/JS/image资源.另请参见如何在Facelets模板?

As to the #{resource} syntax, this is indeed specifically for CSS/JS/image resources placed in /resources folder of public web content. See also How to reference CSS / JS / image resource in Facelets template?

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