DP-5330-Add example codes

src/main/java/com/northconcepts/datapipeline/examples/cookbook/AddValuesToAnArrayUsingGroupByReader.java

@@ -0,0 +1,39 @@
+package com.northconcepts.datapipeline.examples.cookbook;
+
+import com.northconcepts.datapipeline.core.Record;
+import com.northconcepts.datapipeline.core.RecordList;
+import com.northconcepts.datapipeline.core.StreamWriter;
+import com.northconcepts.datapipeline.group.GroupByReader;
+import com.northconcepts.datapipeline.job.Job;
+import com.northconcepts.datapipeline.memory.MemoryReader;
+
+public class AddValuesToAnArrayUsingGroupByReader {
+
+    public static void main(String[] args) {
+        RecordList recordList = new RecordList();
+        recordList.add(createSale("Electronics", "Laptop", 1200));
+        recordList.add(createSale("Books", "Novel", 15));
+        recordList.add(createSale("Electronics", "Mouse", 25));
+        recordList.add(createSale("Clothing", "Shirt", 30));
+        recordList.add(createSale("Books", "Textbook", 90));
+
+        GroupByReader groupByReader = new GroupByReader(new MemoryReader(recordList), "Category");
+
+        groupByReader
+                // Sum the "Price" field and store the result in a new "TotalSales" field.
+                .sum("Price", "TotalSales")
+                // Collect values from the "Product" field into a new array field named "Products".
+                .collect("Product", "Products", false, false, true);
+
+        Job.run(groupByReader, new StreamWriter(System.out));
+    }
+
+    private static Record createSale(String category, String product, double price) {
+        Record record = new Record();
+        record.setField("Category", category);
+        record.setField("Product", product);
+        record.setField("Price", price);
+        return record;
+    }
+
+}

src/main/java/com/northconcepts/datapipeline/examples/cookbook/LookupUsingRecordList.java

@@ -0,0 +1,45 @@
+package com.northconcepts.datapipeline.examples.cookbook;
+
+import com.northconcepts.datapipeline.core.DataReader;
+import com.northconcepts.datapipeline.core.DataWriter;
+import com.northconcepts.datapipeline.core.FieldList;
+import com.northconcepts.datapipeline.core.Record;
+import com.northconcepts.datapipeline.core.RecordList;
+import com.northconcepts.datapipeline.core.StreamWriter;
+import com.northconcepts.datapipeline.job.Job;
+import com.northconcepts.datapipeline.memory.MemoryReader;
+import com.northconcepts.datapipeline.transform.TransformingReader;
+import com.northconcepts.datapipeline.transform.lookup.LookupTransformer;
+import com.northconcepts.datapipeline.transform.lookup.RecordListLookup;
+
+public class LookupUsingRecordList {
+
+    public static void main(String[] args) {
+        RecordList salesOrders = new RecordList();
+        salesOrders.add(new Record().setField("order_id", 101).setField("product_id", 1).setField("quantity", 2));
+        salesOrders.add(new Record().setField("order_id", 102).setField("product_id", 3).setField("quantity", 5));
+        salesOrders.add(new Record().setField("order_id", 103).setField("product_id", 1).setField("quantity", 1));
+        salesOrders.add(new Record().setField("order_id", 104).setField("product_id", 99).setField("quantity", 10)); // No matching product
+
+        DataReader reader = new MemoryReader(salesOrders);
+
+        RecordList productData = new RecordList();
+        productData.add(new Record().setField("id", 1).setField("name", "Laptop").setField("price", 1200.00));
+        productData.add(new Record().setField("id", 2).setField("name", "Mouse").setField("price", 25.50));
+        productData.add(new Record().setField("id", 3).setField("name", "Keyboard").setField("price", 75.00));
+
+        FieldList keyFieldsInLookup = new FieldList("id");
+        FieldList valueFieldsToReturn = new FieldList("name", "price");
+        RecordListLookup productLookup = new RecordListLookup(productData, keyFieldsInLookup, valueFieldsToReturn);
+
+        FieldList keyFieldsInStream = new FieldList("product_id");
+        LookupTransformer lookupTransformer = new LookupTransformer(keyFieldsInStream, productLookup);
+        lookupTransformer.setAllowNoResults(true); // Prevent job failure on no match.
+
+        DataReader transformingReader = new TransformingReader(reader).add(lookupTransformer);
+
+        DataWriter writer = new StreamWriter(System.out);
+
+        Job.run(transformingReader, writer);
+    }
+}

src/main/java/com/northconcepts/datapipeline/examples/cookbook/ReadFromACollection.java

@@ -0,0 +1,64 @@
+package com.northconcepts.datapipeline.examples.cookbook;
+
+import com.northconcepts.datapipeline.core.DataReader;
+import com.northconcepts.datapipeline.core.DataWriter;
+import com.northconcepts.datapipeline.core.Record;
+import com.northconcepts.datapipeline.core.StreamWriter;
+import com.northconcepts.datapipeline.job.Job;
+import com.northconcepts.datapipeline.memory.CollectionReader;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ReadFromACollection {
+
+    public static class User {
+        private final int id;
+        private final String username;
+        private final String email;
+        private final boolean isActive;
+
+        public User(int id, String username, String email, boolean isActive) {
+            this.id = id;
+            this.username = username;
+            this.email = email;
+            this.isActive = isActive;
+        }
+
+        public int getId() {
+            return id;
+        }
+
+        public String getUsername() {
+            return username;
+        }
+
+        public String getEmail() {
+            return email;
+        }
+
+        public boolean isActive() {
+            return isActive;
+        }
+    }
+
+    public static void main(String[] args) {
+        List<User> users = new ArrayList<>();
+        users.add(new User(1, "john.doe", "john.doe@example.com", true));
+        users.add(new User(2, "jane.smith", "jane.smith@example.com", false));
+        users.add(new User(3, "admin", "admin@example.com", true));
+
+        DataReader reader = new CollectionReader<>(users, user -> {
+            Record record = new Record();
+            record.setField("user_id", user.getId());
+            record.setField("username", user.getUsername());
+            record.setField("email_address", user.getEmail());
+            record.setField("active", user.isActive());
+            return record;
+        });
+
+        DataWriter writer = new StreamWriter(System.out);
+
+        Job.run(reader, writer);
+    }
+}

src/main/java/com/northconcepts/datapipeline/examples/cookbook/WriteAJsonFileUsingFreeMarkerTemplates.java

@@ -1,6 +1,8 @@
 package com.northconcepts.datapipeline.examples.cookbook;
 
-import com.northconcepts.datapipeline.core.*;
+import com.northconcepts.datapipeline.core.DataReader;
+import com.northconcepts.datapipeline.core.Record;
+import com.northconcepts.datapipeline.core.RecordList;
 import com.northconcepts.datapipeline.job.Job;
 import com.northconcepts.datapipeline.memory.MemoryReader;
 import com.northconcepts.datapipeline.template.TemplateWriter;

src/main/java/com/northconcepts/datapipeline/foundations/examples/schema/DetectPrimaryKeysInADataset.java

@@ -1,6 +1,11 @@
 package com.northconcepts.datapipeline.foundations.examples.schema;
 
-import com.northconcepts.datapipeline.core.*;
+import com.northconcepts.datapipeline.core.DataReader;
+import com.northconcepts.datapipeline.core.Record;
+import com.northconcepts.datapipeline.core.RecordList;
+import com.northconcepts.datapipeline.core.FieldList;
+import com.northconcepts.datapipeline.core.DataWriter;
+import com.northconcepts.datapipeline.core.StreamWriter;
 import com.northconcepts.datapipeline.job.Job;
 import com.northconcepts.datapipeline.memory.MemoryReader;