Identify and apply Java secure coding practices to reduce vulnerabilities, protect sensitive data, and harden application behaviour against common attack vectors.
Prerequisites: Run ./mvnw compile or mvn compile before applying any changes. If compilation fails, stop immediately — do not proceed until the project is in a valid state.
Core areas: Input validation with type, length, format, and range checks; SQL/OS/LDAP injection defence via PreparedStatement and parameterized APIs; attack surface minimisation through least-privilege permissions and removal of unused features; strong cryptographic algorithms for hashing (passwords with BCrypt/Argon2), encryption (AES-GCM), and digital signatures while avoiding deprecated ciphers (MD5, SHA-1, DES...
Use when you need to apply Java secure coding best practices — including validating untrusted inputs, defending against injection attacks with parameterized queries, minimizing attack surface via least privilege, applying strong cryptographic algorithms, handling exceptions securely without exposing sensitive data, managing secrets at runtime, avoiding unsafe deserialization, and encoding output to prevent XSS. Part of the skills-for-java project Source: jabrena/cursor-rules-java.