refactor: centralize obtaining the DataStream

Author: mlopezFC

src/main/java/com/flowingcode/vaadin/addons/gridexporter/BaseInputStreamFactory.java

@@ -1,22 +1,28 @@
 package com.flowingcode.vaadin.addons.gridexporter;
 
+import java.lang.reflect.Method;
 import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.apache.commons.lang3.tuple.ImmutablePair;
 import org.apache.commons.lang3.tuple.Pair;
+import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import com.flowingcode.vaadin.addons.gridhelpers.GridHelper;
 import com.vaadin.flow.component.ComponentUtil;
 import com.vaadin.flow.component.grid.Grid;
 import com.vaadin.flow.component.grid.Grid.Column;
+import com.vaadin.flow.component.grid.dataview.GridLazyDataView;
+import com.vaadin.flow.data.provider.AbstractBackEndDataProvider;
 import com.vaadin.flow.data.provider.DataCommunicator;
+import com.vaadin.flow.data.provider.DataProvider;
 import com.vaadin.flow.data.provider.Query;
 import com.vaadin.flow.server.InputStreamFactory;
 
 @SuppressWarnings("serial")
 abstract class BaseInputStreamFactory<T> implements InputStreamFactory {
 
+  private final static Logger LOGGER = LoggerFactory.getLogger(BaseInputStreamFactory.class);
   protected GridExporter<T> exporter;
   protected String template;
 
@@ -65,5 +71,28 @@ protected List<Pair<String,Column<T>>> getGridFooters(Grid<T> grid) {
         .collect(Collectors.toList());
   }
 
+  protected Stream<T> obtainDataStream(DataProvider<T, ?> dataProvider) {
+    Object filter = null;
+    try {
+      Method method = DataCommunicator.class.getDeclaredMethod("getFilter");
+      method.setAccessible(true);
+      filter = method.invoke(exporter.grid.getDataCommunicator());
+    } catch (Exception e) {
+      LOGGER.error("Unable to get filter from DataCommunicator", e);
+    }
 
+    Stream<T> dataStream;
+    if (dataProvider instanceof AbstractBackEndDataProvider) {
+      GridLazyDataView<T> gridLazyDataView = exporter.grid.getLazyDataView();
+      dataStream = gridLazyDataView.getItems();
+    } else {
+      @SuppressWarnings({"rawtypes", "unchecked"})
+      Query<T, ?> streamQuery =
+          new Query<>(0, exporter.grid.getDataProvider().size(new Query(filter)),
+              exporter.grid.getDataCommunicator().getBackEndSorting(),
+              exporter.grid.getDataCommunicator().getInMemorySorting(), null);
+      dataStream = getDataStream(streamQuery);
+    }
+    return dataStream;
+  }
 }

src/main/java/com/flowingcode/vaadin/addons/gridexporter/CsvInputStreamFactory.java

@@ -8,7 +8,6 @@
 import java.io.OutputStreamWriter;
 import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
-import java.lang.reflect.Method;
 import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -19,8 +18,6 @@
 import com.vaadin.flow.component.grid.Grid.Column;
 import com.vaadin.flow.data.binder.BeanPropertySet;
 import com.vaadin.flow.data.binder.PropertySet;
-import com.vaadin.flow.data.provider.DataCommunicator;
-import com.vaadin.flow.data.provider.Query;
 
 /**
  * @author mlope
@@ -49,20 +46,7 @@ public void run() {
             List<Pair<String, Column<T>>> headers = getGridHeaders(exporter.grid);
             writer.writeNext(headers.stream().map(pair->pair.getLeft()).collect(Collectors.toList()).toArray(new String[0]));
 
-            Object filter = null;
-            try {
-              Method method = DataCommunicator.class.getDeclaredMethod("getFilter");
-              method.setAccessible(true);
-              filter = method.invoke(exporter.grid.getDataCommunicator());
-            } catch (Exception e) {
-              LOGGER.error("Unable to get filter from DataCommunicator", e);
-            }
-
-            @SuppressWarnings({"rawtypes", "unchecked"})
-            Query<T, ?> streamQuery = new Query<>(0, exporter.grid.getDataProvider().size(new Query(filter)),
-                exporter.grid.getDataCommunicator().getBackEndSorting(),
-                exporter.grid.getDataCommunicator().getInMemorySorting(), null);
-            Stream<T> dataStream = getDataStream(streamQuery);
+            Stream<T> dataStream = obtainDataStream(exporter.grid.getDataProvider());
             dataStream.forEach(t -> {
               writer.writeNext(buildRow(t,writer));
             });

src/main/java/com/flowingcode/vaadin/addons/gridexporter/DocxInputStreamFactory.java

@@ -7,7 +7,6 @@
 import java.io.InputStream;
 import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
-import java.lang.reflect.Method;
 import java.util.Calendar;
 import java.util.Iterator;
 import java.util.List;
@@ -33,9 +32,7 @@
 import com.vaadin.flow.component.grid.Grid.Column;
 import com.vaadin.flow.data.binder.BeanPropertySet;
 import com.vaadin.flow.data.binder.PropertySet;
-import com.vaadin.flow.data.provider.DataCommunicator;
 import com.vaadin.flow.data.provider.DataProvider;
-import com.vaadin.flow.data.provider.Query;
 
 /**
  * @author mlope
@@ -132,20 +129,7 @@ protected XWPFDocument createDoc() throws IOException {
   }
 
   private void fillData(XWPFTable table, XWPFTableCell dataCell, DataProvider<T, ?> dataProvider) {
-    Object filter = null;
-    try {
-      Method method = DataCommunicator.class.getDeclaredMethod("getFilter");
-      method.setAccessible(true);
-      filter = method.invoke(exporter.grid.getDataCommunicator());
-    } catch (Exception e) {
-      LOGGER.error("Unable to get filter from DataCommunicator", e);
-    }
-
-    @SuppressWarnings({"rawtypes", "unchecked"})
-    Query<T, ?> streamQuery = new Query<>(0, exporter.grid.getDataProvider().size(new Query(filter)),
-        exporter.grid.getDataCommunicator().getBackEndSorting(),
-        exporter.grid.getDataCommunicator().getInMemorySorting(), null);
-    Stream<T> dataStream = getDataStream(streamQuery);
+    Stream<T> dataStream = obtainDataStream(dataProvider);
 
     boolean[] firstRow = new boolean[] {true};
     XWPFTableCell[] startingCell = new XWPFTableCell[1];

src/main/java/com/flowingcode/vaadin/addons/gridexporter/ExcelInputStreamFactory.java

@@ -7,7 +7,6 @@
 import java.io.InputStream;
 import java.io.PipedInputStream;
 import java.io.PipedOutputStream;
-import java.lang.reflect.Method;
 import java.text.DateFormat;
 import java.text.DecimalFormat;
 import java.text.ParseException;
@@ -35,13 +34,9 @@
 import com.vaadin.flow.component.ComponentUtil;
 import com.vaadin.flow.component.grid.ColumnTextAlign;
 import com.vaadin.flow.component.grid.Grid.Column;
-import com.vaadin.flow.component.grid.dataview.GridLazyDataView;
 import com.vaadin.flow.data.binder.BeanPropertySet;
 import com.vaadin.flow.data.binder.PropertySet;
-import com.vaadin.flow.data.provider.AbstractBackEndDataProvider;
-import com.vaadin.flow.data.provider.DataCommunicator;
 import com.vaadin.flow.data.provider.DataProvider;
-import com.vaadin.flow.data.provider.Query;
 
 /**
  * @author mlope
@@ -132,30 +127,9 @@ public void run() {
   }
 
 
-  @SuppressWarnings("unchecked")
   private void fillData(Sheet sheet, Cell dataCell, DataProvider<T, ?> dataProvider,
       boolean titleExists) {
-    Object filter = null;
-    try {
-      Method method = DataCommunicator.class.getDeclaredMethod("getFilter");
-      method.setAccessible(true);
-      filter = method.invoke(exporter.grid.getDataCommunicator());
-    } catch (Exception e) {
-      LOGGER.error("Unable to get filter from DataCommunicator", e);
-    }
-
-    Stream<T> dataStream;
-    if (dataProvider instanceof AbstractBackEndDataProvider) {
-      GridLazyDataView<T> gridLazyDataView = exporter.grid.getLazyDataView();
-      dataStream = gridLazyDataView.getItems();
-    } else {
-      @SuppressWarnings("rawtypes")
-      Query<T, ?> streamQuery =
-          new Query<>(0, exporter.grid.getDataProvider().size(new Query(filter)),
-              exporter.grid.getDataCommunicator().getBackEndSorting(),
-              exporter.grid.getDataCommunicator().getInMemorySorting(), null);
-      dataStream = getDataStream(streamQuery);
-    }
+    Stream<T> dataStream = obtainDataStream(dataProvider);
 
     boolean[] notFirstRow = new boolean[1];
     Cell[] startingCell = new Cell[1];