Crate zerodds_idl_java 

IDL4 → Java 17 source codegen (OMG IDL4-Java mapping v1.0).

Crate zerodds-idl-java — Java language bindings, cluster C5.4-a (foundation) plus C5.4-b (bitset/bitmask, multi-inheritance, annotation bridge, TopicType marker).

Safety classification: SAFE (std-only). A pure build-time tool — forbid(unsafe_code), no no_std use case.

Scope (C5.4-a)

• Block A: header layout (package, class modifiers, FQN imports).
• Block B: primitive mapping (boolean → boolean, octet → byte, …, incl. unsigned workaround per spec §6).
• Block C: struct → public class (bean pattern), enum, union → sealed interface + case records, typedef → wrapper class, sequence → java.util.List<T>, array → Java array, single inheritance → extends.
• Block D: Exception → class X extends RuntimeException.

Java version targets

The standard emit targets Java 17: unions use a sealed interface with record case types. Structs/enums/typedefs are bean classes and thus version-neutral.

The opt-in Java-8 compat mode (JavaGenOptions::java8_compat) avoids all Java-9+ constructs: unions are instead emitted as an abstract class with a private constructor (pseudo-sealing) + static final subclasses (final field + constructor + same-named accessor). Everything else is identical in both modes.

Scope (C5.4-b — Cluster E)

• Bitmask → wrapper class with an inner enum Flag and EnumSet<Flag> bits (spec idl4-java-1.0 §6.3).
• Bitset (≤ 64 bits cumulative) → wrapper class with long bits and mask/shift accessors per bitfield. > 64 bits → hard error error::JavaGenError::UnsupportedConstruct.
• Multi-inheritance via an interface pattern: every struct that is itself the base of another struct gets a <Name>Interface.java companion. Sub-sub-classes use extends DirectBase implements GrandparentInterface, ....
• @value(N) on enum members → an explicit int constructor value instead of the auto ordinal.
• Annotation bridge: @key, @id(N), @optional, @must_understand, @external, @nested, @extensibility(...) → Java annotations under org.zerodds.types.* (see runtime/).
• DDS Java PSM stub: every top-level struct without @nested implements org.omg.dds.topic.TopicType<SelfType>.

Deliberately not in the crate

• Clusters F-H: ServiceEnvironment SPI, Time/Duration/Status/QoS/ listener codegen (C5.5).
• Reflection-based TypeRep (java-psm §8) — a stretch goal.
• interface, valuetype, fixed, any, map<K,V> → come with zerodds-rpc-java.

Multi-file output

Java requires one .java file per top-level public class. Therefore generate_java_files returns a Vec<JavaFile>; each JavaFile has a package path + class name + source.

Example

use zerodds_idl::config::ParserConfig;
use zerodds_idl_java::{generate_java_files, JavaGenOptions};

let ast = zerodds_idl::parse(
    "module M { struct S { long x; }; };",
    &ParserConfig::default(),
)
.expect("parse");
let files = generate_java_files(&ast, &JavaGenOptions::default()).expect("gen");
// POJO + TypeSupport (zerodds-xcdr2-java-1.0 §4).
assert_eq!(files.len(), 2);
let pojo = files.iter().find(|f| f.class_name == "S").expect("POJO");
assert!(pojo.source.contains("package m;"));
assert!(pojo.source.contains("public class S"));
assert!(files.iter().any(|f| f.class_name == "STypeSupport"));

Re-exports

pub use emitter::JavaFile;

pub use error::JavaGenError;

Modules

emitter

AST walker that emits Java 17 source files.

error

Error types for the IDL→Java codegen.

keywords

Java-17 keywords (incl. restricted identifiers like record, sealed, var, yield).

rpc

IDL service → Java RPC codegen (DDS-RPC 1.0 §7.11.2 — Java PSM).

type_map

Mapping of IDL primitives to Java type strings.

Structs

JavaGenOptions

Configuration of the Java code generator.

Functions

generate_java_files

Produces a list of Java source files from an IDL specification.

generate_java_files_with_amqp

Convenience variant with the emit_amqp_helpers flag enabled.

generate_java_files_with_corba_traits

Convenience variant with the emit_corba_traits flag enabled.