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Modernize collections

org.openrewrite.staticanalysis.ModernizeCollections

Replace the legacy synchronized types Hashtable, Vector, Stack, and StringBuffer with their modern unsynchronized counterparts HashMap, ArrayList, Deque/ArrayDeque, and StringBuilder. Each replacement is only applied when data flow analysis can prove the instance is a local variable that never escapes its method, so the synchronization it provided is redundant.

Tags​

Recipe source​

GitHub: static-analysis.yml, Issue Tracker, Code Genome Project

Info

This recipe is composed of more than one recipe. If you want to customize the set of recipes this is composed of, you can find and copy the GitHub source for the recipe from the link above.

This recipe is available under the Moderne Source Available License. Moderne customers can download precompiled artifacts from The Code Genome Project. For non-commercial use you can build the artifact from source locally.

Definition​

Usage​

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

OpenRewrite artifacts, including the Maven and Gradle plugins themselves, are distributed through the Code Genome Project repository (https://artifacts.codegenomeproject.org/maven), which requires authentication. Sign in to the Code Genome Project to create a download token; your build authenticates with the email or username you signed in with, plus that token as the password. See the quickstart guide for details.

  1. Put your Code Genome Project credentials in ~/.gradle/gradle.properties, so that they are not committed alongside your build:
    ~/.gradle/gradle.properties
    codeGenomeUsername=you@example.com
    codeGenomeToken=your-download-token
  2. Add the Code Genome Project repository to your settings.gradle file, so that the plugin itself can be resolved:
    settings.gradle
    pluginManagement {
        repositories {
            maven {
                url = "https://artifacts.codegenomeproject.org/maven"
                credentials {
                    username = providers.gradleProperty("codeGenomeUsername").get()
                    password = providers.gradleProperty("codeGenomeToken").get()
                }
            }
            // Keep the portal for any other plugins your build applies
            gradlePluginPortal()
        }
    }
  3. Add the following to your build.gradle file:
    build.gradle
    plugins {
        id("org.openrewrite.rewrite") version("latest.release")
    }

    rewrite {
        activeRecipe("org.openrewrite.staticanalysis.ModernizeCollections")
        setExportDatatables(true)
    }

    repositories {
        mavenCentral()
        maven {
            url = "https://artifacts.codegenomeproject.org/maven"
            credentials {
                username = providers.gradleProperty("codeGenomeUsername").get()
                password = providers.gradleProperty("codeGenomeToken").get()
            }
        }
    }

    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-static-analysis:2.43.0")
    }
  4. Run gradle rewriteRun to run the recipe.

See how this recipe works across multiple open-source repositories​

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Data Tables​

Legacy synchronized types not migrated​

org.openrewrite.staticanalysis.table.LegacySynchronizedTypesNotMigrated

Instances of a legacy synchronized type (Hashtable, Vector, Stack, StringBuffer) that were found but left unchanged because they could not be proven safe to modernize.

Column NameDescription
Source pathThe path to the source file containing the unmigrated reference.
ClassThe fully qualified name of the class containing the reference.
Unmigrated typeThe fully qualified name of the legacy synchronized type that was found but not migrated.
ReasonWhy the instance was left unchanged.