Java Records

Author: lokeshgupta1981

pom.xml

@@ -154,6 +154,11 @@
             <artifactId>assertj-core</artifactId>
             <version>3.16.1</version>
         </dependency>
+        <dependency>
+            <groupId>io.soabase.record-builder</groupId>
+            <artifactId>record-builder-core</artifactId>
+            <version>34</version>
+        </dependency>
     </dependencies>
     <build>
         <sourceDirectory>src/main/java</sourceDirectory>
@@ -179,10 +184,15 @@
                             <artifactId>lombok</artifactId>
                             <version>1.18.22</version>
                         </path>
+                        <path>
+                            <groupId>io.soabase.record-builder</groupId>
+                            <artifactId>record-builder-processor</artifactId>
+                            <version>34</version>
+                        </path>
                     </annotationProcessorPaths>
                 </configuration>
             </plugin>
-            <plugin>
+            <!--<plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-shade-plugin</artifactId>
                 <version>3.2.0</version>
@@ -203,16 +213,15 @@
                         </configuration>
                     </execution>
                 </executions>
-            </plugin>
+            </plugin>-->
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-jar-plugin</artifactId>
                 <version>3.2.0</version>
                 <configuration>
                     <archive>
                         <manifest>
-                            <mainClass>com.howtodoinjava.io.
-                                ReadFileFromResourcesUsingGetResourceAsStream
+                            <mainClass>com.howtodoinjava.io.ReadFileFromResourcesUsingGetResourceAsStream
                             </mainClass>
                         </manifest>
                     </archive>

src/main/java/com/howtodoinjava/core/basic/EmployeeRecord.java

@@ -0,0 +1,30 @@
+package com.howtodoinjava.core.basic;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Consumer;
+
+public class ForEachExamples {
+
+  public static void main(String[] args) {
+    List<String> list = Arrays.asList("A","B","C","D");
+    ArrayList<String> arrayList = new ArrayList<>(list);
+
+    //1
+    list.forEach(System.out::println);
+
+    //2
+    Consumer<String> action = x -> System.out.println(x.toLowerCase());
+    list.forEach(action);
+
+    list.forEach(e -> System.out.println(e.toLowerCase()));
+
+    //3
+    list.forEach(e -> {
+      System.out.println(e.toLowerCase());
+      //other statements
+    });
+  }
+
+}

src/main/java/com/howtodoinjava/core/basic/ForEachExamples.java

@@ -0,0 +1,58 @@
+package com.howtodoinjava.core.basic.record;
+
+import io.soabase.recordbuilder.core.RecordBuilder;
+
+public class BuilderExample {
+
+  public static void main(String[] args) {
+
+    User user = UserBuilder.builder()
+        .id(1l)
+        .name("Lokesh")
+        .email("[email protected]")
+        .status(true)
+        .build();
+
+    System.out.println(user);
+
+    User inactiveUser = UserBuilder.builder(user)
+        .email("[email protected]")
+        .status(true)
+        .build();
+
+    System.out.println(inactiveUser);
+  }
+}
+
+
+//@lombok.Builder
+@RecordBuilder
+record User(long id, String name, String email, boolean status) {
+
+ /* public static final class Builder {
+
+    long id;
+    String name;
+    String email;
+    boolean status;
+
+    public Builder(long id, String name) {
+      this.id = id;
+      this.name = name;
+    }
+
+    public Builder email(String email) {
+      this.email = email;
+      return this;
+    }
+
+    public Builder status(boolean status) {
+      this.status = status;
+      return this;
+    }
+
+    public User build() {
+      return new User(id, name, email, status);
+    }
+  }*/
+}

src/main/java/com/howtodoinjava/core/basic/RecordExample.java

@@ -0,0 +1,35 @@
+package com.howtodoinjava.core.basic.record;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+public record Employee(Long id, String firstName, String lastName, String email, int age)
+    implements Serializable {
+
+  static boolean minor;
+
+  public boolean isMinor() {
+    return minor;
+  }
+
+  public String fullName() {
+    return firstName + " " + lastName;
+  }
+
+  /*public Employee {
+    if (age < 18) {
+      //minor = true;
+      throw new IllegalArgumentException("You cannot hire a minor person as employee");
+    }
+  }
+*/
+  public Employee {
+    Objects.requireNonNull(id);
+    Objects.requireNonNull(email);
+
+    if (age < 18) {
+      throw new IllegalArgumentException("You cannot hire a minor person as employee");
+    }
+  }
+
+}

src/main/java/com/howtodoinjava/core/basic/record/BuilderExample.java

@@ -0,0 +1,17 @@
+package com.howtodoinjava.core.basic.record;
+
+public class GenericRecordExample {
+
+  public static void main(String[] args) {
+    Container<Integer> intContainer = new Container<>(1, Integer.valueOf(1));
+    Container<String> stringContainer = new Container<>(1, "1");
+
+    Integer intValue = intContainer.value();
+    String strValue = stringContainer.value();
+
+
+  }
+}
+
+record Container<T>(int id, T value) {
+}

src/main/java/com/howtodoinjava/core/basic/record/Employee.java

@@ -0,0 +1,43 @@
+package com.howtodoinjava.core.basic.record;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+public class RecordExample {
+
+  public static void main(String[] args) {
+    Employee e = new Employee(1l, "Lokesh", "Gupta", "[email protected]", 38);
+
+    System.out.println(e.id());
+    System.out.println(e.email());
+    System.out.println(e);
+
+    /*writeToFile(e, "employee1");
+    System.out.println(readFromFile("employee1"));*/
+
+    Employee employee = new Employee(1l, "Amit", "Gupta", "[email protected]", 17);
+    System.out.println(employee.isMinor());
+    System.out.println(employee.fullName());
+  }
+
+  static void writeToFile(Employee obj, String path) {
+    try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(path))) {
+      oos.writeObject(obj);
+    } catch (IOException e) {
+      e.printStackTrace();
+    }
+  }
+
+  static Employee readFromFile(String path) {
+    Employee result = null;
+    try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(path))) {
+      result = (Employee) ois.readObject();
+    } catch (ClassNotFoundException | IOException e) {
+      e.printStackTrace();
+    }
+    return result;
+  }
+}