Added ReadRows example

ydb-cookbook/src/main/java/tech/ydb/examples/pagination/PaginationApp.java

@@ -42,7 +42,7 @@ public static void main(String[] args) {
         AppRunner.run("PaginationApp", PaginationApp::new, args);
     }
 
-    public static int test(String[] args, String paginationTest) {
+    public static int test(String[] args) {
         return AppRunner.safeRun("PaginationApp", PaginationApp::new, args);
     }
 

ydb-cookbook/src/main/java/tech/ydb/examples/simple/ReadRowsApp.java

@@ -0,0 +1,199 @@
+package tech.ydb.examples.simple;
+
+
+import java.util.Arrays;
+import java.util.function.Function;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import tech.ydb.core.Result;
+import tech.ydb.core.grpc.GrpcTransport;
+import tech.ydb.examples.App;
+import tech.ydb.examples.AppRunner;
+import tech.ydb.table.SessionRetryContext;
+import tech.ydb.table.TableClient;
+import tech.ydb.table.description.TableDescription;
+import tech.ydb.table.query.ReadRowsResult;
+import tech.ydb.table.result.ResultSetReader;
+import tech.ydb.table.result.ValueReader;
+import tech.ydb.table.settings.BulkUpsertSettings;
+import tech.ydb.table.settings.ReadRowsSettings;
+import tech.ydb.table.settings.ReadTableSettings;
+import tech.ydb.table.values.ListType;
+import tech.ydb.table.values.ListValue;
+import tech.ydb.table.values.PrimitiveType;
+import tech.ydb.table.values.PrimitiveValue;
+import tech.ydb.table.values.StructType;
+import tech.ydb.table.values.StructValue;
+import tech.ydb.table.values.Type;
+import tech.ydb.table.values.Value;
+import tech.ydb.table.values.VoidValue;
+
+/**
+ *
+ * @author Aleksandr Gorshenin
+ */
+public class ReadRowsApp implements App {
+    private static final Logger log = LoggerFactory.getLogger(ReadRowsApp.class);
+
+    private static final String TABLE_NAME = "readrows_test";
+
+    private final String path;
+    private final String tablePath;
+
+    private final TableClient tableClient;
+    private final SessionRetryContext retryCtx;
+
+    ReadRowsApp(GrpcTransport transport, String path) {
+        this.path = path;
+        this.tableClient = TableClient.newClient(transport).build();
+        this.tablePath = this.path + "/" + TABLE_NAME;
+        this.retryCtx = SessionRetryContext.create(tableClient).build();
+    }
+
+    private void createTables() {
+        log.info("drop table {} if exist", tablePath);
+        boolean dropped = retryCtx
+                .supplyStatus(session -> session.dropTable(tablePath))
+                .join().isSuccess();
+        if (!dropped) {
+            log.info("drop table failed");
+        }
+
+        TableDescription table = TableDescription.newBuilder()
+                .addNonnullColumn("id", PrimitiveType.Uint32)
+                .addNullableColumn("text", PrimitiveType.Text)
+                .addNullableColumn("payload", PrimitiveType.Bytes)
+                .setPrimaryKey("id")
+                .build();
+
+        log.info("create table {}", tablePath);
+        retryCtx.supplyStatus(session -> session.createTable(tablePath, table))
+                .join().expectSuccess("create table fail");
+    }
+
+    private void writeData() {
+        ListValue bulkData = Record.makeYdbBulk(
+                new Record(1, "id1", new byte[]{0, 1, 2}),
+                new Record(2, "id2", new byte[]{1, 1, 1, 1, 1}),
+                new Record(3, "", new byte[]{}),
+                new Record(4, null, null)
+        );
+
+        retryCtx.supplyStatus(session -> session.executeBulkUpsert(
+                tablePath, bulkData, new BulkUpsertSettings()
+        )).join().expectSuccess("bulk upsert problem");
+    }
+
+    private void readRows() {
+        ReadRowsSettings settings = ReadRowsSettings.newBuilder().addKeys(
+                StructValue.of("id", PrimitiveValue.newUint32(1)),
+                StructValue.of("id", PrimitiveValue.newUint32(2)),
+                StructValue.of("id", PrimitiveValue.newUint32(3)),
+                StructValue.of("id", PrimitiveValue.newUint32(4))
+        ).build();
+
+        Result<ReadRowsResult> result = retryCtx.supplyResult(session -> session.readRows(tablePath, settings))
+                .join();
+
+        ResultSetReader rs = result.getValue().getResultSetReader();
+        while (rs.next()) {
+            log.info("Readed row " + new Record(rs));
+        }
+    }
+
+    private void readTable() {
+        ReadTableSettings settings = ReadTableSettings.newBuilder().orderedRead(true).build();
+        retryCtx.supplyStatus(session -> session.executeReadTable(tablePath, settings).start(part -> {
+            ResultSetReader rs = part.getResultSetReader();
+            while (rs.next()) {
+                log.info("Readed from table " + new Record(rs));
+            }
+        })).join().expectSuccess();
+    }
+
+    @Override
+    public void run() {
+        createTables();
+        writeData();
+        readRows();
+        readTable();
+    }
+
+    @Override
+    public void close() {
+        tableClient.close();
+    }
+
+    public static int test(String[] args) {
+        return AppRunner.safeRun("ReadRowsApp", ReadRowsApp::new, args);
+    }
+
+    public static void main(String[] args) {
+        AppRunner.run("ReadRowsApp", ReadRowsApp::new, args);
+    }
+
+    private static <T> T readColumn(ResultSetReader rs, String name, Function<ValueReader, T> method) {
+        Type type = rs.getColumnType(rs.getColumnIndex(name));
+        ValueReader reader = rs.getColumn(name);
+        if (type.getKind() == Type.Kind.OPTIONAL && !reader.isOptionalItemPresent()) {
+            return null;
+        }
+        return method.apply(reader);
+    }
+
+    private static class Record {
+        private static final StructType TYPE = StructType.of(
+                "id", PrimitiveType.Uint32,
+                "text", PrimitiveType.Text,
+                "payload", PrimitiveType.Bytes
+        );
+
+        private final long id;
+        private final String text;
+        private final byte[] payload;
+
+        Record(long id, String text, byte[] payload) {
+            this.id = id;
+            this.text = text;
+            this.payload = payload;
+        }
+
+        Record(ResultSetReader rs) {
+            this.id = readColumn(rs, "id", ValueReader::getUint32);
+            this.text = readColumn(rs, "text", ValueReader::getText);
+            this.payload = readColumn(rs, "payload", ValueReader::getBytes);
+        }
+
+        @Override
+        public String toString() {
+            StringBuilder sb = new StringBuilder("Record[id=");
+            sb.append(id);
+            if (text != null) {
+                sb.append(", text='").append(text).append("'");
+            }
+            if (payload != null) {
+                sb.append(", payload=").append(Arrays.toString(payload));
+            }
+            return sb.append("]").toString();
+        }
+
+        public Value<?> toYdbValue() {
+            return TYPE.newValue(
+                    "id", PrimitiveValue.newUint32(id),
+                    "text", text == null ? VoidValue.of() : PrimitiveValue.newText(text),
+                    "payload", payload == null ? VoidValue.of() : PrimitiveValue.newBytes(payload)
+            );
+        }
+
+        public static ListValue makeYdbBulk(Record... records) {
+            Value<?>[] values = new Value<?>[records.length];
+            for (int idx = 0; idx < records.length; idx += 1) {
+                log.info("Write record {} ", records[idx]);
+                values[idx] = records[idx].toYdbValue();
+            }
+            return ListType.of(TYPE).newValueOwn(values);
+        }
+    }
+}

ydb-cookbook/src/test/java/tech/ydb/examples/ExamplesTest.java

@@ -8,6 +8,7 @@
 import tech.ydb.examples.bulk_upsert.BulkUpsert;
 import tech.ydb.examples.pagination.PaginationApp;
 import tech.ydb.examples.simple.ComplexTransaction;
+import tech.ydb.examples.simple.ReadRowsApp;
 import tech.ydb.examples.simple.ReadTableExample;
 import tech.ydb.test.junit5.YdbHelperExtension;
 
@@ -51,7 +52,12 @@ public void testReadTable() {
 
     @Test
     public void testPagination() {
-        Assertions.assertEquals(0, PaginationApp.test(args(), "Pagination test"));
+        Assertions.assertEquals(0, PaginationApp.test(args()), "Pagination test");
+    }
+
+    @Test
+    public void testReadRows() {
+        Assertions.assertEquals(0, ReadRowsApp.test(args()), "Read rows test");
     }
 
     @Test