apache/dubbo · error · UnsupportedOperationException

source == null

Error message

source == null

What it means

Thrown by JavaFileObjectImpl.getCharContent when source is null. This happens when a JavaFileObjectImpl was constructed for output (CLASS kind) or by URI, which do not carry source text, yet the compiler framework calls getCharContent expecting to read source.

Solutions

1. This is typically internal to JdkCompiler; ensure you are using a supported Compiler SPI and not calling JavaFileObjectImpl directly.
2. Upgrade Dubbo to a version where the JdkCompiler file-object lifecycle is correctly managed.
3. If extending JdkCompiler, only call getCharContent on file objects constructed with source text.

try {
    fileObject.getCharContent(true);
} catch (UnsupportedOperationException e) {
    // this file object has no source; use one created with source text
}

When it happens

Trigger: The JSR-199 framework or internal code calls getCharContent on a JavaFileObjectImpl that was created via the (name, Kind) or (URI, Kind) constructors (source == null) instead of the (baseName, CharSequence) constructor.

Common situations: An internal Dubbo JdkCompiler path where the file manager hands a class-output file object to a code path that then tries to read its source. Generally an internal/library-internal condition rather than a direct user API misuse.

Related errors

• Compilation failed. class
• Can't create adaptive extension
• Class not found
• Failed to compile class, cause
• is unknown primitive type.

AI-assisted analysis of apache/dubbo@3a3043227f (2026-08-14). Data as JSON: /api/errors/4d2633c72948ec31. Report an issue: GitHub.

Appendix: source

Thrown at dubbo-common/src/main/java/org/apache/dubbo/common/compiler/support/JdkCompiler.java:156

        public JavaFileObjectImpl(final String baseName, final CharSequence source) {
            super(ClassUtils.toURI(baseName + ClassUtils.JAVA_EXTENSION), Kind.SOURCE);
            this.source = source;
        }

        JavaFileObjectImpl(final String name, final Kind kind) {
            super(ClassUtils.toURI(name), kind);
            source = null;
        }

        public JavaFileObjectImpl(URI uri, Kind kind) {
            super(uri, kind);
            source = null;
        }

        @Override
        public CharSequence getCharContent(final boolean ignoreEncodingErrors) throws UnsupportedOperationException {
            if (source == null) {
                throw new UnsupportedOperationException("source == null");
            }
            return source;
        }

        @Override
        public InputStream openInputStream() {
            return new ByteArrayInputStream(getByteCode());
        }

        @Override
        public OutputStream openOutputStream() {
            return bytecode = new ByteArrayOutputStream();
        }

        public byte[] getByteCode() {
            return bytecode.toByteArray();
        }
    }

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