Spring is a popular Java application framework for creating enterprise applications. Spring ClassPathResource ClassPathResource allows to obtain resources from a Java classpath.
What is the use of classpathresource in Spring Boot?
ClassPathResource allows to obtain resources from a Java classpath. The application reads text data from a file located in the Java classpath. This is the project structure. In the pom.xml file, we have basic Spring dependencies spring-core and spring-context and logging logback-classic dependency.
What is the purpose of the classpathresource implementation?
This implementation creates a ClassPathResource, applying the given path relative to the path of the underlying resource of this descriptor. This implementation compares the underlying class path locations. This implementation checks for the resolution of a resource URL.
What is the difference between relativepath and classpathresource?
This implementation creates a ClassPathResource, applying the given path relative to the path of the underlying resource of this descriptor. relativePath - the relative path (relative to this resource)
What is the use of resourceloader in spring?
The ResourceLoader interface in Spring is meant to be implemented by objects that can load and return a Resource instance. All application Contexts implements this interface. There are several implementations of ResourceLoader available in Spring.
What is a ClassPathResource?
public class ClassPathResource extends AbstractFileResolvingResource. Resource implementation for class path resources. Uses either a given ClassLoader or a given Class for loading resources. Supports resolution as java. io.
What is @resource in spring boot?
Spring's Implementations for Resource Interface interface: URLResource: Represents a resource loaded from a URL. ClassPathResource: Represents a resource loaded from the classpath. FileSystemResource: Represents a resource loaded from the filesystem. ServletContextResource: This implementation is for.
What is class path resource in Java?
Classpath in Java is not only used to load . class files, but also can be used to load resources e.g. properties files, images, icons, thumbnails, or any binary content. Java provides API to read these resources as InputStream or URL.
What is the use of @resource in Spring?
The @Resource annotation in spring performs the autowiring functionality. This annotation follows the autowire=byName semantics in the XML based configuration i.e. it takes the name attribute for the injection. Below snippet shows how to use this annotation. This annotation takes an optional name argument.
What is @inject in Spring boot?
Dependency Injection is a fundamental aspect of the Spring framework, through which the Spring container “injects” objects into other objects or “dependencies”. Simply put, this allows for loose coupling of components and moves the responsibility of managing components onto the container.
What is @inject annotation in Java?
A method annotated with @Inject that overrides another method annotated with @Inject will only be injected once per injection request per instance. A method with no @Inject annotation that overrides a method annotated with @Inject will not be injected. Injection of members annotated with @Inject is required.
What is the classpath in Spring boot?
By default Spring Boot will serve static content from a directory called /static (or /public or /resources or /META-INF/resources) in the classpath.
How do I load a file in classpath?
We can either load the file(present in resources folder) as inputstream or URL format and then perform operations on them. So basically two methods named: getResource() and getResourceAsStream() are used to load the resources from the classpath. These methods generally return the URL's and input streams respectively.
How do I find a file in classpath?
The file can be present at the root of classpath location or in any relative sub-directory....The classpath of an application generally contains the following locations:Project's root directory./src/main/resources.Any location whose files are copied to /classes folder after project build runs.
What is the use of @autowired in Spring boot?
The @Autowired annotation provides more fine-grained control over where and how autowiring should be accomplished. The @Autowired annotation can be used to autowire bean on the setter method just like @Required annotation, constructor, a property or methods with arbitrary names and/or multiple arguments.
What is difference between @bean and @autowired?
@Bean is just for the metadata definition to create the bean(equivalent to tag). @Autowired is to inject the dependancy into a bean(equivalent to ref XML tag/attribute).
What is difference between @inject and @autowired?
@Inject and @Autowired both annotations are used for autowiring in your application. @Inject annotation is part of Java CDI which was introduced in Java 6, whereas @Autowire annotation is part of spring framework. Both annotations fulfill same purpose therefore, anything of these we can use in our application. Sr.
1. Introduction
In this tutorial, we'll demonstrate various ways to access and load the contents of a file that's on the classpath using Spring.
A Guide to the ResourceBundle
It's always challenging to maintain and extend multilingual applications. This article covers how to use the ResourceBundle to cope with the varieties that come up when you need to provide the same content to different cultures.
Load a Resource as a String in Spring
Learn how to inject the contents of a resource file into our beans as a String, with Spring's Resource class making this very easy.
2. Using Resource
The Resource interface helps in abstracting access to low-level resources. In fact, it supports the handling of all kinds of file resources in a uniform manner.
3. Using ResourceUtils
As a caveat, there is another way to retrieve resources in Spring, but the ResourceUtils Javadoc is clear that the class is mainly for internal use.
4. Reading Resource Data
Once we have a Resource, it's easy for us to read the contents. As we have already discussed, we can easily obtain a File or an InputStream reference from the Resource.
5. Conclusion
In this brief article, we've examined a few ways to access and read a resource from the classpath using Spring. This includes eager and lazy loading, and on the filesystem or in a jar.
1. Resource interface in Spring
Java provides java.net.URL class for handling standard URL resources. However, it cannot load a resource from classpath or relative to ServletContext and so on. Spring provides additional features to deal with these resources.
2. Use the ResourceLoader interface
The ResourceLoader interface in Spring is meant to be implemented by objects that can load and return a Resource instance. All application Contexts implements this interface.
3. Use the ResourceLoaderAware interface
In the above section, we learned to use the ResourceLoader interface. Spring also provides a way to automatically inject a ResourceLoader in your custom components by implementing ResourceLoaderAware interface.
4. Resource string usages
You have seen in the above examples, the classpath resources are passed as classpath:com/myapp/config.xml and the URL resources as https://myserver/logo.png. There are proper prefixes which should be used to indicate its type and location.
Conclusion
This article has given you information on Resource, ResourceLoader & ResourceLoaderAware. You have learned about the Resources in Spring and how Spring handles them internally. I have not gone deep on each of these topics but discussed to keep you informed. Let me know your thoughts on the comments below.
1. ClassPathResource
ClassPathResource is a Resource implementation for class path resources.
2. Read file from resources using ResourceLoader
Instead of using ClassPathResource, we can also use ResourceLoader for loading resources (e.. class path or file system resources).
