How to fetch file from azure blob using spring boot - azure-blob-storage

Question

I want to fetch files from Azure blob storage. Following code does it fine-
package com.<your-resource-group>.<your-artifact-name>;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.Resource;
import org.springframework.core.io.WritableResource;
import org.springframework.util.StreamUtils;
import org.springframework.web.bind.annotation.*;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;
#RestController
#RequestMapping("blob")
public class BlobController {
#Value("azure-blob://<your-container-name>/<your-blob-name>")
private Resource blobFile;
#GetMapping("/readBlobFile")
public String readBlobFile() throws IOException {
return StreamUtils.copyToString(
this.blobFile.getInputStream(),
Charset.defaultCharset());
}
#PostMapping("/writeBlobFile")
public String writeBlobFile(#RequestBody String data) throws IOException {
try (OutputStream os = ((WritableResource) this.blobFile).getOutputStream()) {
os.write(data.getBytes());
}
return "file was updated";
}
}
My Question -
The #Value annotation provides value to the Resource that is static (i.e I cannot put any variable containing my path as a string inside #Value).
How can I implement the this

Answer 1

In application properties try storing the path
#application.properties
blob.path=
We can use #Value("${...property's name}") annotation to access the above property in the Java class as follows:
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
#RestController
public class ValueController {
#Value("${blob.path}")
private String path;
#GetMapping("")
..
}
}
Here try to use blob uri complete path in application properties and use the same in #value annotation as variable by map datatype
//
#Value("${blob.path}")
private Map<String, String> blobPath;
See this > java - How to read external properties based on value of local variable in Spring Boot? - Stack Overflow
& Value Spring: Spring #Value annotation tricks - DEV Community
Also see Requestmapping
Other references :
Spring Azure Blob Storage | DevGlan
spring batch - How to read the csv files from Azure Blob Storage in
Java with folder structure as 'dir1 / dir2 / dir3 /..'? - Stack Overflow