Step 5: Add receipt.png

You can use the Java Client Libraries to save non-RDF resources (e.g., .png , .pdf ) to your Pod.

For this part of the tutorial, the getting started app uses Inrupt’s Java client library to:

• Store a copy of the expense receipts to your Pod.

• Update the associated expense to link to the URLs of the receipts.

You can find the complete code at Complete Code.

Update application.properties

Add the following properties to the src/main/resources/application.properties file:

spring.servlet.multipart.max-file-size=128KB
spring.servlet.multipart.max-request-size=128KB

Modify Expense Class

1. Open Expense class file:

Java

Open src/main/java/com/example/gettingstarted/Expense.java

Kotlin

Open src/main/kotlin/com/example/gettingstarted/Expense.kt

1. Add the java.util.* import statement:

Java

import java.util.*;

Kotlin

import java.util.*

1. Add the predicate definition for the receipts in the Expense class:

Java

static IRI SCHEMA_ORG_IMAGE = rdf.createIRI("https://schema.org/image");

Kotlin

var SCHEMA_ORG_IMAGE: IRI = rdf.createIRI("https://schema.org/image")

1. Update the Expense class constructor to include the receipts:

Java

@JsonCreator
public Expense(@JsonProperty("identifier") final URI identifier,
               @JsonProperty("merchantProvider") String merchantProvider,
               @JsonProperty("expenseDate") Date expenseDate,
               @JsonProperty("description") String description,
               @JsonProperty("amount") BigDecimal amount,
               @JsonProperty("currency") String currency,
               @JsonProperty("category") String category,
               @JsonProperty("receipts") String[] receipts) {
    this(identifier);</strong>
    this.setRDFType(MY_RDF_TYPE_VALUE);
    this.setMerchantProvider(merchantProvider);
    this.setExpenseDate(expenseDate);
    this.setDescription(description);
    this.setAmount(amount);
    this.setCurrency(currency);
    this.setCategory(category);
    this.setReceipts(receipts);
}

Kotlin

@JsonCreator
constructor(
    @JsonProperty("identifier") identifier: URI,
    @JsonProperty("merchantProvider") merchantProvider: String?,
    @JsonProperty("expenseDate") expenseDate: Date,
    @JsonProperty("description") description: String?,
    @JsonProperty("amount") amount: BigDecimal?,
    @JsonProperty("currency") currency: String?,
    @JsonProperty("category") category: String?,
    @JsonProperty(&quot;receipts&quot;) receipts: Set<String>?
) : this(identifier, rdf.createDataset(), Headers.empty()) {
    this.rdfType = MY_RDF_TYPE_VALUE
    this.merchantProvider = merchantProvider
    this.expenseDate = expenseDate
    this.description = description
    this.amount = amount
    this.currency = currency
    this.category = category
    this.receipts = receipts
}

1. Add the getter and setters for the receipts in the Expense class:

Java

public Set<String> getReceipts() {
    return subject.getReceipts();
}
// Note:: The setters first uses the getter, which returns a Set, and adds the receipt to the set.
public void addReceipt(String receipt) {
    subject.getReceipts().add(receipt);
}
public void setReceipts(String[] receipts) {
    subject.getReceipts().addAll(List.of(receipts));
}

Kotlin

// Note:: The setters first uses the getter, which returns a Set, and adds the receipt to the set.

var receipts: Set<String>?
    get() = subject.receipts
    set(receipts) {
        if (receipts != null) {
            subject.receipts.addAll(receipts)
        }
    }
fun addReceipt(receipt: String) {
    subject.receipts.add(receipt)
}

1. Add getter for the receipts in the inner Node class:

Java

public Set<String> getReceipts() {
    return objects(SCHEMA_ORG_IMAGE, TermMappings::asIri, ValueMappings::iriAsString);
}

Kotlin

val receipts: MutableSet<String>
    get() = objects(SCHEMA_ORG_IMAGE, TermMappings::asIri, ValueMappings::iriAsString)

Note For more detail with regards to handling lists, see https://github.com/inrupt/docs-gitbook/tree/main/sdk/java-sdk/tutorial/step5/broken-reference/README.md.

Modify ExpenseController Class

1. Open ExpenseController class file.

Java

Open src/main/java/com/example/gettingstarted/ExpenseController.java

Kotlin

Open src/main/kotlin/com/example/gettingstarted/ExpenseController.kt

1. Add the following import statements:

Java

import com.inrupt.client.solid.SolidNonRDFSource;
import org.springframework.web.multipart.MultipartFile;

Kotlin

import com.inrupt.client.solid.SolidNonRDFSource
import org.springframework.web.multipart.MultipartFile

1. Add the following method to handle the upload of non-RDF files:

Java

/**
 * Note 9: Stores a non-RDF resource to a Pod
 *
 * Using SolidNonRDFSource and the SolidSyncClient .create() method,
 * - Saves a non-RDF resource at the destinationURL.
 */
@PutMapping("**/resource/nonRDF/add**")
public String addNonRDFFile(@RequestParam(value = "destinationURL") String destinationURL,
                            @RequestParam(value = "file") MultipartFile file) {
    printWriter.println("In addNonRDFFile:: Save Non-RDF File to Pod.");
    try (final var fileStream = file.getInputStream()) {
        SolidNonRDFSource myNonRDFFile = new SolidNonRDFSource(URI.create(destinationURL), file.getContentType(), fileStream);
        return client.create(myNonRDFFile).getIdentifier().toString();
    } catch(PreconditionFailedException e1) {
        // Errors if the resource already exists
        printWriter.println(String.format("[%s] com.inrupt.client.solid.PreconditionFailedException in addNonRDFFile:: %s", e1.getStatusCode(), e1.getMessage()));
    } catch(ForbiddenException e2) {
        // Errors if user does not have access to create
        printWriter.println(String.format("[%s] com.inrupt.client.solid.ForbiddenException in addNonRDFFile:: %s", e2.getStatusCode(), e2.getMessage()));
    } catch(Exception e) {
        e.printStackTrace();
    }
    return null;
}

Kotlin

/**
 * Note 9: Stores a non-RDF resource to a Pod
 *
 * Using SolidNonRDFSource and the SolidSyncClient's .create() method,
 * - Saves a non-RDF resource at the destinationURL.
 */
@PutMapping("**/resource/nonRDF/add**")
fun addNonRDFFile(
    @RequestParam(value = "destinationURL") destinationURL: String,
    @RequestParam(value = "file") file: MultipartFile
): String? {
    printWriter.println("In addNonRDFFile: Save Non-RDF File to Pod.")
    try {
        file.inputStream.use { fileStream ->
           val myNonRDFFile: SolidNonRDFSource = SolidNonRDFSource(URI.create(destinationURL), file.contentType, fileStream)
           return client.create(myNonRDFFile).identifier.toString()
        }
    } catch(e1: PreconditionFailedException) {
        // Errors if the resource already exists
        printWriter.println(String.format("[%s] com.inrupt.client.solid.PreconditionFailedException in addNonRDFFile:: %s", e1.statusCode, e1.localizedMessage))
    } catch(e2: ForbiddenException) {
        // Errors if user does not have access to create
        printWriter.println(String.format("[%s] com.inrupt.client.solid.ForbiddenException in addNonRDFFile:: %s", e2.statusCode, e2.localizedMessage))
    } catch (e: Exception) {
        e.printStackTrace()
    }
    return ""
}

1. Add the following method that uploads a receipt file and links it to the associated Expense.

Java

/**
 * Note 10: Stores a non-RDF resource (image of the receipt) to a Pod and Attach to an Expense
 * Using methods defined as part of getting started, addReceiptToExpense:
 * - Calls addNonRDFFile() to store the receipt to a Pod
 * - Calls getExpense() to fetch the associated Expense RDF resource.
 * - Calls the Expense's setter `addReceipt` to add the link to the saved receipt.
 * - Calls updateExpense() to save the updated Expense.
 */
@PutMapping("**/expenses/receipts/add**")
public Expense addReceiptToExpense(@RequestParam(value = "destinationURL") String destinationURL,
                                   @RequestParam(value = "file") MultipartFile file,
                                   @RequestParam(value = "expenseURL") String expenseURL) {
    printWriter.println("In addReceiptToExpense: Save Receipt File to Pod and Update Associated Expense.");
    try {
        String receiptLocation = addNonRDFFile(destinationURL, file);
        if (receiptLocation != null) {
            Expense expense = getExpense(expenseURL);
            expense.addReceipt(receiptLocation);
            return updateExpense(expense);
        } else {
            printWriter.println("Error adding receipt");
            return null;
        }
    } catch(ForbiddenException e2) {
        // Errors if user does not have access to read or update the Expense resource
        printWriter.println(String.format("[%s] com.inrupt.client.solid.ForbiddenException in addReceiptToExpense:: %s", e2.getStatusCode(), e2.getMessage()));
    } catch(Exception e) {
        e.printStackTrace();
    }
    return null;
}

Kotlin

/**
 * Note 10: Stores a non-RDF resource (image of the receipt) to a Pod and Attach to an Expense
 * Using methods defined as part of getting started, addReceiptToExpense:
 * - Calls addNonRDFFile() to store the receipt to a Pod
 * - Calls getExpense() to fetch the associated Expense RDF resource.
 * - Calls the Expense's setter `addReceipt` to add the link to the saved receipt.
 * - Calls updateExpense() to save the updated Expense.
 */
@PutMapping("**/expenses/receipts/add**")
fun addReceiptToExpense(
    @RequestParam(value = "destinationURL") destinationURL: String,
    @RequestParam(value = "file") file: MultipartFile,
    @RequestParam(value = "expenseURL") expenseURL: String
): Expense? {
    printWriter.println("In AddReceiptToExpense: Save Receipt File to Pod and Update Associated Expense.")
    val receiptLocation = addNonRDFFile(destinationURL, file)
    return if (!receiptLocation.isNullOrEmpty()) {
        val expense = getExpense(expenseURL)
        if (expense != null) {
            expense.addReceipt(receiptLocation)
            updateExpense(expense)
        } else {
            null
        }
    } else {
        printWriter.println("Error adding receipt")
        null
    }
}