Fix #800 - Remove boiler plate code for listAfter and listBefore methods in TableRepository

catalog-rest-service/src/main/java/org/openmetadata/catalog/jdbi3/EntityRepository.java

@@ -0,0 +1,33 @@
+package org.openmetadata.catalog.jdbi3;
+
+import org.openmetadata.catalog.util.EntityUtil.Fields;
+import org.openmetadata.catalog.util.ResultList;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.security.GeneralSecurityException;
+import java.text.ParseException;
+import java.util.List;
+
+/**
+ * Interface used for accessing the concrete entity DAOs such as table, dashboard etc.
+ * This gives a uniform access so that common boiler plate code can be reduced.
+ */
+public interface EntityRepository<T> {
+  /**
+   * DAO related operations
+   */
+  List<String> listAfter(String fqnPrefix, int limitParam, String after);
+  List<String> listBefore(String fqnPrefix, int limitParam, String before);
+  int listCount(String fqnPrefix);
+
+
+  /**
+   * Entity related operations
+   */
+  String getFullyQualifiedName(T entity);
+  T setFields(T entity, Fields fields) throws IOException, ParseException;
+
+  ResultList<T> getResultList(List<T> entities, String beforeCursor, String afterCursor,
+                              int total) throws GeneralSecurityException, UnsupportedEncodingException;
+}

catalog-rest-service/src/main/java/org/openmetadata/catalog/jdbi3/TableRepository.java

@@ -45,6 +45,7 @@ import org.openmetadata.catalog.util.EventUtils;
 import org.openmetadata.catalog.util.JsonUtils;
 import org.openmetadata.catalog.util.RestUtil;
 import org.openmetadata.catalog.util.RestUtil.PutResponse;
+import org.openmetadata.catalog.util.ResultList;
 import org.openmetadata.common.utils.CipherText;
 import org.openmetadata.common.utils.CommonUtil;
 import org.skife.jdbi.v2.sqlobject.Bind;
@@ -58,6 +59,7 @@ import org.slf4j.LoggerFactory;
 import javax.json.JsonPatch;
 import javax.ws.rs.core.Response.Status;
 import java.io.IOException;
+import java.io.UnsupportedEncodingException;
 import java.security.GeneralSecurityException;
 import java.text.ParseException;
 import java.util.ArrayList;
@@ -113,47 +115,49 @@ public abstract class TableRepository {
   @CreateSqlObject
   abstract TagDAO tagDAO();
 
+  EntityRepository<Table> entityRepository = new EntityRepository<Table>() {
+    @Override
+    public List<String> listAfter(String fqnPrefix, int limitParam, String after) {
+      return tableDAO().listAfter(fqnPrefix, limitParam, after);
+    }
+
+    @Override
+    public List<String> listBefore(String fqnPrefix, int limitParam, String after) {
+      return tableDAO().listBefore(fqnPrefix, limitParam, after);
+    }
+
+    @Override
+    public int listCount(String fqnPrefix) {
+      return tableDAO().listCount(fqnPrefix);
+    }
+
+    @Override
+    public String getFullyQualifiedName(Table entity) {
+      return entity.getFullyQualifiedName();
+    }
+
+    @Override
+    public Table setFields(Table entity, Fields fields) throws IOException, ParseException {
+      return TableRepository.this.setFields(entity, fields);
+    }
+
+    @Override
+    public ResultList<Table> getResultList(List<Table> entities, String beforeCursor, String afterCursor, int total)
+            throws GeneralSecurityException, UnsupportedEncodingException {
+      return new TableList(entities, beforeCursor, afterCursor, total);
+    }
+  };
+
   @Transaction
-  public TableList listAfter(Fields fields, String databaseFQN, int limitParam, String after) throws IOException,
+  public ResultList<Table> listAfter(Fields fields, String databaseFQN, int limitParam, String after)
-          ParseException, GeneralSecurityException {
+          throws IOException, ParseException, GeneralSecurityException {
-    // forward scrolling, if after == null then first page is being asked being asked
+      return EntityUtil.listAfter(entityRepository, Table.class, fields, databaseFQN, limitParam, after);
-    List<String> jsons = tableDAO().listAfter(databaseFQN, limitParam + 1, after == null ? "" :
-            CipherText.instance().decrypt(after));
-
-    List<Table> tables = new ArrayList<>();
-    for (String json : jsons) {
-      tables.add(setFields(JsonUtils.readValue(json, Table.class), fields));
-    }
-    int total = tableDAO().listCount(databaseFQN);
-
-    String beforeCursor, afterCursor = null;
-    beforeCursor = after == null ? null : tables.get(0).getFullyQualifiedName();
-    if (tables.size() > limitParam) { // If extra result exists, then next page exists - return after cursor
-      tables.remove(limitParam);
-      afterCursor = tables.get(limitParam - 1).getFullyQualifiedName();
-    }
-    return new TableList(tables, beforeCursor, afterCursor, total);
   }
 
   @Transaction
-  public TableList listBefore(Fields fields, String databaseFQN, int limitParam, String before) throws IOException,
+  public ResultList<Table> listBefore(Fields fields, String databaseFQN, int limitParam, String before)
-          ParseException, GeneralSecurityException {
+          throws IOException, ParseException, GeneralSecurityException {
-    // Reverse scrolling - Get one extra result used for computing before cursor
+    return EntityUtil.listBefore(entityRepository, Table.class, fields, databaseFQN, limitParam, before);
-    List<String> jsons = tableDAO().listBefore(databaseFQN, limitParam + 1, CipherText.instance().decrypt(before));
-
-    List<Table> tables = new ArrayList<>();
-    for (String json : jsons) {
-      tables.add(setFields(JsonUtils.readValue(json, Table.class), fields));
-    }
-    int total = tableDAO().listCount(databaseFQN);
-
-    String beforeCursor = null, afterCursor;
-    if (tables.size() > limitParam) { // If extra result exists, then previous page exists - return before cursor
-      tables.remove(0);
-      beforeCursor = tables.get(0).getFullyQualifiedName();
-    }
-    afterCursor = tables.get(tables.size() - 1).getFullyQualifiedName();
-    return new TableList(tables, beforeCursor, afterCursor, total);
   }
 
   @Transaction

catalog-rest-service/src/main/java/org/openmetadata/catalog/resources/databases/TableResource.java

@@ -130,7 +130,7 @@ public class TableResource {
                   content = @Content(mediaType = "application/json",
                           schema = @Schema(implementation = TableList.class)))
           })
-  public TableList list(@Context UriInfo uriInfo,
+  public ResultList<Table> list(@Context UriInfo uriInfo,
                                 @Context SecurityContext securityContext,
                                 @Parameter(description = "Fields requested in the returned resource",
                                 schema = @Schema(type = "string", example = FIELDS))
@@ -154,7 +154,7 @@ public class TableResource {
     RestUtil.validateCursors(before, after);
     Fields fields = new Fields(FIELD_LIST, fieldsParam);
 
-    TableList tables;
+    ResultList<Table> tables;
     if (before != null) { // Reverse paging
       tables = dao.listBefore(fields, databaseParam, limitParam, before);
     } else { // Forward paging or first page

catalog-rest-service/src/main/java/org/openmetadata/catalog/util/EntityUtil.java

@@ -38,6 +38,7 @@ import org.openmetadata.catalog.exception.EntityNotFoundException;
 import org.openmetadata.catalog.jdbi3.ChartRepository.ChartDAO;
 import org.openmetadata.catalog.jdbi3.DashboardRepository.DashboardDAO;
 import org.openmetadata.catalog.jdbi3.DatabaseRepository.DatabaseDAO;
+import org.openmetadata.catalog.jdbi3.EntityRepository;
 import org.openmetadata.catalog.jdbi3.EntityRelationshipDAO;
 import org.openmetadata.catalog.jdbi3.MetricsRepository.MetricsDAO;
 import org.openmetadata.catalog.jdbi3.ModelRepository.ModelDAO;
@@ -72,12 +73,15 @@ import org.openmetadata.catalog.type.TagLabel;
 import org.openmetadata.catalog.type.TagLabel.LabelType;
 import org.openmetadata.catalog.type.UsageDetails;
 import org.openmetadata.catalog.type.UsageStats;
+import org.openmetadata.common.utils.CipherText;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.ws.rs.WebApplicationException;
 import javax.ws.rs.core.UriInfo;
 import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -431,7 +435,7 @@ public final class EntityUtil {
           throws IOException {
     String entityType = entityLink.getEntityType();
     String fqn = entityLink.getEntityId();
-    if(entityType.equalsIgnoreCase(Entity.USER)) {
+    if (entityType.equalsIgnoreCase(Entity.USER)) {
       return getEntityReference(EntityUtil.validate(fqn, userDAO.findByName(fqn), User.class));
     } else if (entityType.equalsIgnoreCase(Entity.TEAM)) {
       return getEntityReference(EntityUtil.validate(fqn, teamDAO.findByName(fqn), Team.class));
@@ -650,4 +654,47 @@ public final class EntityUtil {
       return fieldList.contains(field);
     }
   }
+
+  public static <T> ResultList<T> listAfter(EntityRepository<T> dao, Class<T> clz, Fields fields, String prefixFqn,
+                                            int limitParam, String after)
+          throws IOException, ParseException, GeneralSecurityException {
+    // forward scrolling, if after == null then first page is being asked being asked
+    List<String> jsons = dao.listAfter(prefixFqn, limitParam + 1, after == null ? "" :
+            CipherText.instance().decrypt(after));
+
+    List<T> entities = new ArrayList<>();
+    for (String json : jsons) {
+      entities.add(dao.setFields(JsonUtils.readValue(json, clz), fields));
+    }
+    int total = dao.listCount(prefixFqn);
+
+    String beforeCursor, afterCursor = null;
+    beforeCursor = after == null ? null : dao.getFullyQualifiedName(entities.get(0));
+    if (entities.size() > limitParam) { // If extra result exists, then next page exists - return after cursor
+      entities.remove(limitParam);
+      afterCursor = dao.getFullyQualifiedName(entities.get(limitParam - 1));
+    }
+    return dao.getResultList(entities, beforeCursor, afterCursor, total);
+  }
+
+  public static <T> ResultList<T> listBefore(EntityRepository<T> dao, Class<T> clz, Fields fields, String databaseFQN,
+                                             int limitParam, String before)
+          throws IOException, ParseException, GeneralSecurityException {
+    // Reverse scrolling - Get one extra result used for computing before cursor
+    List<String> jsons = dao.listBefore(databaseFQN, limitParam + 1, CipherText.instance().decrypt(before));
+
+    List<T> entities = new ArrayList<>();
+    for (String json : jsons) {
+      entities.add(dao.setFields(JsonUtils.readValue(json, clz), fields));
+    }
+    int total = dao.listCount(databaseFQN);
+
+    String beforeCursor = null, afterCursor;
+    if (entities.size() > limitParam) { // If extra result exists, then previous page exists - return before cursor
+      entities.remove(0);
+      beforeCursor = dao.getFullyQualifiedName(entities.get(0));
+    }
+    afterCursor = dao.getFullyQualifiedName(entities.get(entities.size() - 1));
+    return dao.getResultList(entities, beforeCursor, afterCursor, total);
+  }
 }