SonarSource Rules
  • Products

    In-IDE

    Code Quality and Security in your IDE with SonarQube Ide

    IDE extension that lets you fix coding issues before they exist!

    Discover SonarQube for IDE

    SaaS

    Code Quality and Security in the cloud with SonarQube Cloud

    Setup is effortless and analysis is automatic for most languages

    Discover SonarQube Cloud

    Self-Hosted

    Code Quality and Security Self-Hosted with SonarQube Server

    Fast, accurate analysis; enterprise scalability

    Discover SonarQube Server
  • SecretsSecrets
  • ABAPABAP
  • AnsibleAnsible
  • ApexApex
  • AzureResourceManagerAzureResourceManager
  • CC
  • C#C#
  • C++C++
  • CloudFormationCloudFormation
  • COBOLCOBOL
  • CSSCSS
  • DartDart
  • DockerDocker
  • FlexFlex
  • GitHub ActionsGitHub Actions
  • GoGo
  • HTMLHTML
  • JavaJava
  • JavaScriptJavaScript
  • JSONJSON
  • JCLJCL
  • KotlinKotlin
  • KubernetesKubernetes
  • Objective CObjective C
  • PHPPHP
  • PL/IPL/I
  • PL/SQLPL/SQL
  • PythonPython
  • RPGRPG
  • RubyRuby
  • RustRust
  • ScalaScala
  • ShellShell
  • SwiftSwift
  • TerraformTerraform
  • TextText
  • TypeScriptTypeScript
  • T-SQLT-SQL
  • VB.NETVB.NET
  • VB6VB6
  • XMLXML
  • YAMLYAML
Java

Java static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your JAVA code

  • All rules 733
  • Vulnerability60
  • Bug175
  • Security Hotspot40
  • Code Smell458

  • Quick Fix 65
Filtered: 1 rule found
struts
    Impact
      Clean code attribute
        1. Servlets should not have mutable instance fields

           Bug

        Servlets should not have mutable instance fields

        intentionality - clear
        reliability
        Bug
        • multi-threading
        • struts
        • cert

        Why is this an issue?

        How can I fix it?

        More Info

        The processHttpRequest method and methods called from it can be executed by multiple threads within the same servlet instance, and state changes to the instance caused by these methods are, therefore, not threadsafe.

        This is due to the servlet container creating only one instance of each servlet (javax.servlet.http.HttpServlet) and attaching a dedicated thread to each incoming HTTP request. The same problem exists for org.apache.struts.action.Action but with different methods.

        To prevent unexpected behavior, avoiding mutable states in servlets is recommended. Mutable instance fields should either be refactored into local variables or made immutable by declaring them final.

        Exceptions

        • Fields annotated with @javax.inject.Inject, @javax.ejb.EJB, @org.springframework.beans.factory.annotation.Autowired, @javax.annotation.Resource
        • Fields initialized in init() or init(ServletConfig config) methods
          Available In:
        • SonarQube IdeCatch issues on the fly,
          in your IDE
        • SonarQube CloudDetect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories
        • SonarQube Community BuildAnalyze code in your
          on-premise CI
          Available Since
          9.1
        • SonarQube ServerAnalyze code in your
          on-premise CI
          Developer Edition
          Available Since
          9.1

        © 2008-2025 SonarSource SA. All rights reserved.

        Privacy Policy | Cookie Policy | Terms of Use