- Optimize zip-file creation.

- Update dependencies.

build.gradle

@@ -1,5 +1,5 @@
 plugins {
-    id 'org.springframework.boot' version '2.6.6'
+    id 'org.springframework.boot' version '2.7.0'
     id 'io.spring.dependency-management' version '1.0.11.RELEASE'
     id 'java'
 }
@@ -26,7 +26,7 @@ dependencies {
     implementation("org.springframework.security:spring-security-config")
     //implementation("io.jsonwebtoken:jjwt:0.9.1")  // Use this in case we use auth-tokens later on.
 
-    implementation "org.projectlombok:lombok:1.18.22"
+    implementation 'org.projectlombok:lombok:1.18.24'
 
     // Enable the validation annotations.
     //implementation group: 'javax.validation', name: 'validation-api', version: '2.0.1.Final'

src/main/java/eu/openaire/urls_worker/util/FilesZipper.java

@@ -5,6 +5,7 @@ import org.slf4j.LoggerFactory;
 
 import java.io.*;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.util.List;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
@@ -22,7 +23,7 @@ public class FilesZipper
 
         int numZippedFiles = 0;
         File zipFile = new File(zipFilename);
-        try ( ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(zipFile), StandardCharsets.UTF_8) )
+        try ( ZipOutputStream zos = new ZipOutputStream(Files.newOutputStream(zipFile.toPath()), StandardCharsets.UTF_8) )
         {
             for ( String file : filesToZip ) {
                 if ( zipAFile(file, zos, baseDirectory) )
@@ -37,20 +38,16 @@ public class FilesZipper
     }
 
 
-    private static final int BUFFER_SIZE = 3145728;	// 3MB (average fullText-size)
-    private static final byte[] dataBuffer = new byte[BUFFER_SIZE];
-
-    // This method is "synchronized" to avoid any future problems with shared-buffer, if the requests are asynchronous.
-    private static synchronized boolean zipAFile(String fileName, ZipOutputStream zos, String baseDir)
+    private static boolean zipAFile(String fileName, ZipOutputStream zos, String baseDir)
     {
-        boolean shouldCloseEntry = false;   // Useful in order to close the entry in case of an exception.
+        boolean shouldCloseEntry = false;   // Useful in order to know if we should close the entry (an Exception may appear, and so we should not try to close it).
         String fullFileName = baseDir + fileName;
-        try ( BufferedInputStream bis = new BufferedInputStream(new FileInputStream(fullFileName), BUFFER_SIZE) ) {
+        try (FileInputStream fis = new FileInputStream(fullFileName)) {
             zos.putNextEntry(new ZipEntry(fileName));
             shouldCloseEntry = true;
-            int count;
-            while ( (count = bis.read(dataBuffer, 0, BUFFER_SIZE)) != -1 ) {
-                zos.write(dataBuffer, 0, count);
+            int readByte;
+            while ( (readByte = fis.read()) != -1 ) {
+                zos.write(readByte);
             }
         } catch (FileNotFoundException fnfe) {
             logger.error("Error zipping file: " + fullFileName, fnfe.getMessage());

src/main/java/eu/openaire/urls_worker/util/UriBuilder.java

@@ -26,7 +26,6 @@ public class UriBuilder {
             sslEnabled = "false";
         }
         baseUrl += sslEnabled.equals("true") ? "s" : "";
-
         baseUrl += "://";
 
         String hostName = getPublicIP();