migrateclassnewinstancetogetdeclaredconstructornewinstance.md

Use Class#getDeclaredConstructor().newInstance()

org.openrewrite.java.migrate.lang.MigrateClassNewInstanceToGetDeclaredConstructorNewInstance

Use Class#getDeclaredConstructor().newInstance() instead of the deprecated Class#newInstance() in Java 9 or higher.

Tags

• deprecated

Source

GitHub, Issue Tracker, Maven Central

• groupId: org.openrewrite.recipe
• artifactId: rewrite-migrate-java
• version: 2.0.1

Example

{% tabs %} {% tab title="com/abc/A.java" %}

Before

{% code title="com/abc/A.java" %}

package com.abc;

class A {
   public void test() throws Throwable {
       Class<?> class_ = Class.forName("org.openrewrite.Test");
       class_.newInstance();
   }
}

{% endcode %}

After

{% code title="com/abc/A.java" %}

package com.abc;

class A {
   public void test() throws Throwable {
       Class<?> class_ = Class.forName("org.openrewrite.Test");
       class_.getDeclaredConstructor().newInstance();
   }
}

{% endcode %}

{% endtab %} {% tab title="Diff" %} {% code %}

--- com/abc/A.java
+++ com/abc/A.java
@@ -6,1 +6,1 @@
   public void test() throws Throwable {
       Class<?> class_ = Class.forName("org.openrewrite.Test");
-      class_.newInstance();
+      class_.getDeclaredConstructor().newInstance();
   }

{% endcode %} {% endtab %} {% endtabs %}

Usage

This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-migrate-java:2.0.1 in your build file or by running a shell command (in which case no build changes are needed): {% tabs %} {% tab title="Gradle" %} {% code title="build.gradle" %}

plugins {
    id("org.openrewrite.rewrite") version("6.1.4")
}

rewrite {
    activeRecipe("org.openrewrite.java.migrate.lang.MigrateClassNewInstanceToGetDeclaredConstructorNewInstance")
}

repositories {
    mavenCentral()
}

dependencies {
    rewrite("org.openrewrite.recipe:rewrite-migrate-java:2.0.1")
}

{% endcode %} {% endtab %} {% tab title="Maven POM" %} {% code title="pom.xml" %}

<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>5.2.4</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.java.migrate.lang.MigrateClassNewInstanceToGetDeclaredConstructorNewInstance</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-migrate-java</artifactId>
            <version>2.0.1</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

{% endcode %} {% endtab %}

{% tab title="Maven Command Line" %} {% code title="shell" %} You will need to have Maven installed on your machine before you can run the following command.

mvn -U org.openrewrite.maven:rewrite-maven-plugin:run \
  -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-migrate-java:RELEASE \
  -Drewrite.activeRecipes=org.openrewrite.java.migrate.lang.MigrateClassNewInstanceToGetDeclaredConstructorNewInstance

{% endcode %} {% endtab %} {% endtabs %}

Contributors

• Patrick
• Sam Snyder
• Tyler Van Gorder
• Jonathan Schnéider
• Josh Soref
• Knut Wannheden
• Aaron Gershman

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