#29480

dotCMS/src/main/java/com/dotcms/jobs/business/processor/impl/LargeFileReader.java

@@ -0,0 +1,168 @@
+package com.dotcms.jobs.business.processor.impl;
+
+import com.dotcms.jobs.business.error.JobCancellationException;
+import com.dotcms.jobs.business.job.Job;
+import com.dotcms.jobs.business.processor.Cancellable;
+import com.dotcms.jobs.business.processor.JobProcessor;
+import com.dotcms.jobs.business.processor.Queue;
+import com.dotcms.rest.api.v1.temp.DotTempFile;
+import com.dotcms.rest.api.v1.temp.TempFileAPI;
+import com.dotmarketing.business.APILocator;
+import com.dotmarketing.util.Logger;
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * This class reads a large file and prints the content to the log.
+ * It is here for the sole purpose of demonstrating the job queue system.
+ */
+@Queue("FileReader")
+public class LargeFileReader implements JobProcessor, Cancellable {
+
+    private boolean working = true;
+
+    @Override
+    public void process(Job job) {
+        // Retrieve job parameters
+        working = true;
+
+        Logger.info(this.getClass(), "Processing job: " + job.id());
+        Map<String, Object> params = job.parameters();
+
+        final Optional<Integer> linesParam = linesParam(params);
+        if (linesParam.isEmpty()) {
+            Logger.error(this.getClass(),
+                    "Unable to retrieve the number of lines to read. Quitting the job.");
+            return;
+        }
+
+        Optional<DotTempFile> tempFile = tempFile(params);
+        if (tempFile.isEmpty()) {
+            Logger.error(this.getClass(), "Unable to retrieve the temporary. Quitting the job.");
+            return;
+        }
+
+        final int nLines = linesParam.get();
+        final DotTempFile dotTempFile = tempFile.get();
+
+        doReadLargeFile(dotTempFile, nLines);
+    }
+
+    /**
+     * Process the job
+     * @param dotTempFile temporary file
+     * @param nLines number of lines to read and print
+     */
+    private void doReadLargeFile(DotTempFile dotTempFile, int nLines) {
+        try (BufferedReader reader = new BufferedReader(new FileReader(dotTempFile.file))) {
+            String line;
+            int lineCount = 0;
+            int totalLines = 0;
+
+            Logger.info(this.getClass(),
+                    "Starting to read the file: " + dotTempFile.file.getName());
+
+            while (working && (line = reader.readLine()) != null) {
+                lineCount++;
+                totalLines++;
+
+                // Print the line when the counter reaches nLines
+                if (lineCount == nLines) {
+                    Logger.info(this.getClass(), "Line " + totalLines + ": " + line);
+                    lineCount = 0; // Reset the counter
+                }
+            }
+
+            Logger.info(this.getClass(), "Reading completed. Total lines read: " + totalLines);
+        } catch (Exception e) {
+            Logger.error(this.getClass(), "Unexpected error during processing: " + e.getMessage());
+        }
+    }
+
+    /**
+     * Retrieve the number of lines to read from the parameters
+     *
+     * @param params input parameters
+     * @return the number of lines to read
+     */
+    Optional<Integer> linesParam(Map<String, Object> params) {
+
+        final Object nLinesRaw = params.get("nLines");
+        if (!(nLinesRaw instanceof String)) {
+            Logger.error(this.getClass(), "Parameter 'nLines' is required and must be a string.");
+            return Optional.empty();
+        }
+
+        int nLines;
+        try {
+            nLines = Integer.parseInt((String) nLinesRaw);
+        } catch (NumberFormatException e) {
+            Logger.error(this.getClass(), "Parameter 'nLines' must be a valid integer.", e);
+            return Optional.empty();
+        }
+
+        // Validate required parameters
+        if (nLines <= 0) {
+            Logger.error(this.getClass(), "Parameters 'tempFileId' are required.");
+            return Optional.empty();
+        }
+
+        return Optional.of(nLines);
+    }
+
+    /**
+     * Retrieve the temporary file from the parameters
+     *
+     * @param params input parameters
+     * @return the temporary file
+     */
+    Optional<DotTempFile> tempFile(Map<String, Object> params) {
+        // Extract parameters
+        String tempFileId = (String) params.get("tempFileId");
+
+        final Object requestFingerPrintRaw = params.get("requestFingerPrint");
+        if (!(requestFingerPrintRaw instanceof String)) {
+            Logger.error(this.getClass(),
+                    "Parameter 'requestFingerPrint' is required and must be a string.");
+            return Optional.empty();
+        }
+        final String requestFingerPrint = (String) requestFingerPrintRaw;
+
+        // Retrieve the temporary file
+        final TempFileAPI tempFileAPI = APILocator.getTempFileAPI();
+        final Optional<DotTempFile> tempFile = tempFileAPI.getTempFile(List.of(requestFingerPrint),
+                tempFileId);
+        if (tempFile.isEmpty()) {
+            Logger.error(this.getClass(), "Temporary file not found: " + tempFileId);
+            return Optional.empty();
+        }
+
+        return tempFile;
+    }
+
+    /**
+     * Provide metadata for the job result.
+     * @param job The job for which to provide metadata.
+     * @return The metadata for the job result.
+     */
+    @Override
+    public Map<String, Object> getResultMetadata(Job job) {
+        return Map.of();
+    }
+
+    /**
+     * Cancel the job
+     * @param job
+     * @throws JobCancellationException
+     */
+    @Override
+    public void cancel(Job job) throws JobCancellationException {
+        Logger.info(this.getClass(), "Job cancelled: " + job.id());
+        working = false;
+    }
+
+
+}

dotCMS/src/main/java/com/dotcms/rest/api/v1/job/JobParams.java

@@ -43,6 +43,9 @@ public void setJsonParams(String jsonParams) {
 
     public Map getParams() throws JsonProcessingException {
         if (null == params) {
+            if (null == jsonParams){
+                throw new IllegalArgumentException("Job Params must be passed in json format.");
+            }
             params = new ObjectMapper().readValue(jsonParams, Map.class);
         }
         return params;