Tests only

src/main/java/org/openrewrite/java/spring/RequiredFieldIntoConstructorParameter.java

@@ -0,0 +1,26 @@
+package org.openrewrite.java.spring;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaIsoVisitor;
+
+public class RequiredFieldIntoConstructorParameter extends Recipe {
+
+    @Override
+    public String getDisplayName() {
+        return "Required FieldInto Constructor Parameter";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Moves attributes for setters maker with @Required annotation to constructor parameter.";
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        return new JavaIsoVisitor<ExecutionContext>() {
+
+        };
+    }
+}

src/testWithSpringBoot_2_1/java/org/openrewrite/java/spring/RequiredFieldIntoConstructorParameterTest.java

@@ -0,0 +1,89 @@
+package org.openrewrite.java.spring;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.java.JavaParser;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.java.Assertions.java;
+
+class RequiredFieldIntoConstructorParameterTest implements RewriteTest {
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new RequiredFieldIntoConstructorParameter())
+          .parser(JavaParser.fromJavaVersion().classpath("spring-beans"));
+    }
+
+    @Test
+    void fieldIntoExistingSingleConstructor() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              package demo;
+              import org.springframework.beans.factory.annotation.Required;
+              
+               public class Test {
+                   private String a;
+              
+                   @Required
+                   void setA(String a) {
+                       this.a = a;
+                   }
+               }
+              """,
+            """
+              package demo;
+              
+              public class Test {
+                  private final String a;
+    
+                  Test(String a) {
+                      this.a = a;
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    public void requiredFieldIntoConstructorParameter() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              package demo;
+              import org.springframework.beans.factory.annotation.Required;
+              
+              public class Test {
+                 private String first;
+                 private String a;
+              
+                 Test(String first, String a) {
+                    this.first = first;
+                  }
+              
+                 @Required
+                 void setA(String a) {
+                     this.a = a;
+                 }
+              }
+              """,
+            """
+              package demo;
+              
+              public class Test {
+                 private String first;
+                 private final String a;
+             
+                Test(String first, String a) {
+                    this.first = first;
+                    this.a = a;
+                 }
+              }
+              """
+          )
+        );
+    }
+}