Add recipe to migrate System.out.print/println to IO.print/println

src/main/java/org/openrewrite/java/migrate/io/ReplaceSystemOutWithIOPrint.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.java.migrate.io;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaIsoVisitor;
+import org.openrewrite.java.JavaTemplate;
+import org.openrewrite.java.MethodMatcher;
+import org.openrewrite.java.search.UsesMethod;
+import org.openrewrite.java.tree.Expression;
+import org.openrewrite.java.tree.J;
+import org.openrewrite.java.tree.TypeUtils;
+
+public class ReplaceSystemOutWithIOPrint extends Recipe {
+
+    @Override
+    public String getDisplayName() {
+        return "Migrate `System.out.print` to Java 25 IO utility class";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Replace `System.out.print()`, `System.out.println()` with `IO.print()` and `IO.println()`. " +
+                "Migrates to the new IO utility class introduced in Java 25.";
+    }
+
+    private static final MethodMatcher SYSTEM_OUT_PRINT = new MethodMatcher("java.io.PrintStream print(..)");
+    private static final MethodMatcher SYSTEM_OUT_PRINTLN = new MethodMatcher("java.io.PrintStream println(..)");
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        return Preconditions.check(
+                Preconditions.or(
+                        new UsesMethod<>(SYSTEM_OUT_PRINT),
+                        new UsesMethod<>(SYSTEM_OUT_PRINTLN)
+                ),
+                new JavaIsoVisitor<ExecutionContext>() {
+                    @Override
+                    public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
+                        J.MethodInvocation m = super.visitMethodInvocation(method, ctx);
+                        if (!isSystemOutMethod(m)) {
+                            return m;
+                        }
+                        String methodName = m.getName().getSimpleName();
+                        return m.getArguments().isEmpty() ?
+                                JavaTemplate.builder("IO.#{}()").build()
+                                        .apply(getCursor(), m.getCoordinates().replace(), methodName) :
+                                JavaTemplate.builder("IO.#{}(#{any()})").build()
+                                        .apply(getCursor(), m.getCoordinates().replace(), methodName, m.getArguments().get(0));
+                    }
+
+                    private boolean isSystemOutMethod(J.MethodInvocation mi) {
+                        if (SYSTEM_OUT_PRINT.matches(mi) || SYSTEM_OUT_PRINTLN.matches(mi)) {
+                            Expression expression = mi.getSelect();
+                            if (expression instanceof J.FieldAccess) {
+                                return isSystemOut(((J.FieldAccess) expression).getName());
+                            }
+                            if (expression instanceof J.Identifier) {
+                                maybeRemoveImport("java.lang.System.out");
+                                return isSystemOut((J.Identifier) expression);
+                            }
+                        }
+                        return false;
+                    }
+
+                    private boolean isSystemOut(J.Identifier identifier) {
+                        return "out".equals(identifier.getSimpleName()) &&
+                                identifier.getFieldType() != null &&
+                                TypeUtils.isAssignableTo("java.lang.System", identifier.getFieldType().getOwner());
+                    }
+                });
+    }
+}

src/main/resources/META-INF/rewrite/java-version-25.yml

@@ -30,6 +30,7 @@ recipeList:
       version: 25
   - org.openrewrite.github.SetupJavaUpgradeJavaVersion:
       minimumJavaMajorVersion: 25
+  - org.openrewrite.java.migrate.io.ReplaceSystemOutWithIOPrint
   - org.openrewrite.java.migrate.lang.MigrateProcessWaitForDuration
   - org.openrewrite.java.migrate.lang.ReplaceUnusedVariablesWithUnderscore
   - org.openrewrite.java.migrate.util.MigrateInflaterDeflaterToClose

src/test/java/org/openrewrite/java/migrate/io/ReplaceSystemOutWithIOPrintTest.java

@@ -0,0 +1,263 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://docs.moderne.io/licensing/moderne-source-available-license
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.java.migrate.io;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
+import org.openrewrite.java.JavaParser;
+import org.openrewrite.java.search.FindMissingTypes;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+import org.openrewrite.test.TypeValidation;
+
+import static org.openrewrite.java.Assertions.java;
+import static org.openrewrite.java.Assertions.javaVersion;
+
+class ReplaceSystemOutWithIOPrintTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new ReplaceSystemOutWithIOPrint())
+          .afterTypeValidationOptions(TypeValidation.all().allowMissingType(o -> {
+              assert o instanceof FindMissingTypes.MissingTypeResult;
+              FindMissingTypes.MissingTypeResult result = (FindMissingTypes.MissingTypeResult) o;
+              return result.getPrintedTree().contains("IO");
+          })) // TODO remove once tests run on Java 25+
+          .parser(JavaParser.fromJavaVersion())
+          .allSources(s -> s.markers(javaVersion(25)));
+    }
+
+    @DocumentExample
+    @Test
+    void replaceSystemOutPrint() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      System.out.print("Hello");
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      IO.print("Hello");
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void replaceSystemOutPrintln() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      System.out.println("Hello");
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      IO.println("Hello");
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void replaceSystemOutPrintlnWithStaticImport() {
+        rewriteRun(
+          java(
+            """
+              import static java.lang.System.out;
+
+              class Example {
+                  void test() {
+                      out.println("Hello");
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      IO.println("Hello");
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void replaceSystemOutPrintWithVariable() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      String message = "Hello World";
+                      System.out.print(message);
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      String message = "Hello World";
+                      IO.print(message);
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void replaceSystemOutPrintlnEmpty() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      System.out.println();
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      IO.println();
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void replaceMultipleSystemOutCalls() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      System.out.print("Hello");
+                      System.out.println(" World");
+                      System.out.print(42);
+                      System.out.println();
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      IO.print("Hello");
+                      IO.println(" World");
+                      IO.print(42);
+                      IO.println();
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void handlesPrintWithComplexExpressions() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      String name = "John";
+                      int age = 30;
+                      System.out.print("Name: " + name + ", Age: " + age);
+                      System.out.println(String.format("Formatted: %s is %d years old", name, age));
+                  }
+              }
+              """,
+            """
+              class Example {
+                  void test() {
+                      String name = "John";
+                      int age = 30;
+                      IO.print("Name: " + name + ", Age: " + age);
+                      IO.println(String.format("Formatted: %s is %d years old", name, age));
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void doesNotReplaceSystemErrCalls() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      System.err.print("Error message");
+                      System.err.println("Error message");
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void doesNotReplaceOtherPrintStreams() {
+        rewriteRun(
+          java(
+            """
+              import java.io.PrintStream;
+
+              class Example {
+                  void test() {
+                      PrintStream ps = new PrintStream(System.out);
+                      ps.print("Should not change");
+                      ps.println("Should not change");
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void doesNotReplacePrintf() {
+        rewriteRun(
+          java(
+            """
+              class Example {
+                  void test() {
+                      System.out.printf("Hello%n");
+                  }
+              }
+              """
+          )
+        );
+    }
+}