fix: fix search alternative

src/main/java/de/caritas/cob/userservice/api/adapters/web/controller/SearchQueryDecoder.java

@@ -0,0 +1,32 @@
+package de.caritas.cob.userservice.api.adapters.web.controller;
+
+import static com.google.common.collect.Lists.newArrayList;
+
+import com.github.jknack.handlebars.internal.lang3.StringUtils;
+import com.google.common.base.Splitter;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+import java.util.stream.Collectors;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class SearchQueryDecoder {
+
+  private static final String SEPARATOR = "+";
+
+  /* Allows the query string to contain plus sign, but not change it to space.
+  See https://bugs.openjdk.org/browse/JDK-8179507 */
+  public static String decode(String query) {
+    if (StringUtils.isBlank(query)) {
+      return StringUtils.EMPTY;
+    }
+    var parts = Splitter.on(SEPARATOR).split(query);
+    return newArrayList(parts).stream()
+        .map(SearchQueryDecoder::decodePart)
+        .collect(Collectors.joining(SEPARATOR)).trim();
+  }
+
+  private static String decodePart(String s) {
+    return URLDecoder.decode(s, StandardCharsets.UTF_8);
+  }
+}

src/main/java/de/caritas/cob/userservice/api/adapters/web/controller/UserController.java

@@ -777,7 +777,7 @@ public ResponseEntity<List<ConsultantResponseDTO>> getConsultants(@RequestParam
   @Override
   public ResponseEntity<ConsultantSearchResultDTO> searchConsultants(
       String query, Integer page, Integer perPage, String field, String order) {
-    var decodedInfix = URLDecoder.decode(query, StandardCharsets.UTF_8).trim();
+    var decodedInfix = SearchQueryDecoder.decode(query);
     var isAscending = order.equalsIgnoreCase("asc");
     var mappedField = consultantDtoMapper.mappedFieldOf(field);
     var resultMap =

src/test/java/de/caritas/cob/userservice/api/adapters/web/controller/SearchQueryDecoderTest.java

@@ -0,0 +1,24 @@
+package de.caritas.cob.userservice.api.adapters.web.controller;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class SearchQueryDecoderTest {
+
+  @ParameterizedTest
+  @CsvSource({
+    "[email protected], [email protected]",
+    "*, *",
+    "[email protected], [email protected]",
+    "A Test, A Test",
+    ",''",
+    "\"\",\"\"",
+    "stringWithoutPlusSign,stringWithoutPlusSign",
+    "firstname.lastname%2Bconsultant%40virtual-identity.com, [email protected]"
+  })
+  void decode_Should_Decode_String_Not_ChangingPlusIntoSpace(String input, String expectedOutput) {
+    assertThat(SearchQueryDecoder.decode(input).trim()).isEqualTo(expectedOutput);
+  }
+}