Remove catch for a checked exception if the try block does not throw that exception

org.openrewrite.staticanalysis.UnnecessaryCatch

A refactoring operation may result in a checked exception that is no longer thrown from a try block. This recipe will find and remove unnecessary catch blocks.

Recipe source

GitHub, Issue Tracker, Maven Central

• groupId: org.openrewrite.recipe

• artifactId: rewrite-static-analysis

• version: 1.5.0

Options

Type	Name	Description	Example
boolean	includeJavaLangException	Optional. Whether to include java.lang.Exception in the list of checked exceptions to remove. Unlike other checked exceptions, java.lang.Exception is also the superclass of unchecked exceptions. So removing catch(Exception e) may result in changed runtime behavior in the presence of unchecked exceptions. Default false

Usage

This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-static-analysis:1.5.0 in your build file or by running a shell command (in which case no build changes are needed):

Gradle

1. Add the following to your build.gradle file:

build.gradle

plugins {
    id("org.openrewrite.rewrite") version("6.12.0")
}

rewrite {
    activeRecipe("org.openrewrite.staticanalysis.UnnecessaryCatch")
}

repositories {
    mavenCentral()
}

dependencies {
    rewrite("org.openrewrite.recipe:rewrite-static-analysis:1.5.0")
}

2. Run gradle rewriteRun to run the recipe.

Gradle init script

1. Create a file named init.gradle in the root of your project.

init.gradle

initscript {
    repositories {
        maven { url "https://plugins.gradle.org/m2" }
    }
    dependencies { classpath("org.openrewrite:plugin:6.12.0") }
}
rootProject {
    plugins.apply(org.openrewrite.gradle.RewritePlugin)
    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-static-analysis:1.5.0")
    }
    rewrite {
        activeRecipe("org.openrewrite.staticanalysis.UnnecessaryCatch")
    }
    afterEvaluate {
        if (repositories.isEmpty()) {
            repositories {
                mavenCentral()
            }
        }
    }
}

2. Run gradle --init-script init.gradle rewriteRun to run the recipe.

Maven POM

1. Add the following to your pom.xml file:

pom.xml

<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>5.29.0</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.staticanalysis.UnnecessaryCatch</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-static-analysis</artifactId>
            <version>1.5.0</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

2. Run mvn rewrite:run to run the recipe.

Maven Command Line

shell

mvn -U org.openrewrite.maven:rewrite-maven-plugin:run -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-static-analysis:RELEASE -Drewrite.activeRecipes=org.openrewrite.staticanalysis.UnnecessaryCatch

Moderne CLI

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell

mod run . --recipe UnnecessaryCatch

See how this recipe works across multiple open-source repositories

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Please contact Moderne for more information about safely running the recipes on your own codebase in a private SaaS.

Contributors

Tyler Van Gorder, Sam Snyder, Knut Wannheden, Tim te Beek, Jonathan Schnéider