A guide for Java developers moving any Java PDF library — iText, PDFBox, or similar — to PDFluent in Rust. Covers the ownership model, error handling, and deployment changes.
cargo add pdfluentJava PDF libraries use object graphs you mutate through method calls. PDFluent exposes the same operations — open, read, fill, save — through a Rust API. Start by listing every PDF operation your code performs and find the PDFluent equivalent in the docs.
// pom.xml
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext7-core</artifactId>
<version>7.2.5</version>
<type>pom</type>
</dependency>
// Or for PDFBox:
// <groupId>org.apache.pdfbox</groupId>
// <artifactId>pdfbox</artifactId>
// <version>3.0.0</version># Cargo.toml
[dependencies]
pdfluent = "0.9"Java PDF libraries throw checked exceptions — you surround every call with try/catch and manage cleanup in finally blocks. Rust uses the Result type. The ? operator propagates errors up the call stack automatically, and ownership ensures resources are freed when values go out of scope. There is no finally block because there is no need for one.
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import java.io.IOException;
PdfDocument pdf = null;
try {
pdf = new PdfDocument(new PdfReader("report.pdf"));
String text = PdfTextExtractor.getTextFromPage(
pdf.getPage(1),
new LocationTextExtractionStrategy()
);
System.out.println(text);
} catch (IOException e) {
System.err.println("Failed to open PDF: " + e.getMessage());
} finally {
if (pdf != null) pdf.close();
}use pdfluent::Document;
fn process_report() -> pdfluent::Result<()> {
let doc = Document::open("report.pdf")?;
let text = doc.page(0)?.extract_text()?;
println!("{}", text);
Ok(())
// doc is freed automatically when it goes out of scope
}A Java PDF service requires a JVM at the deployment target, adds 200-400 MB to your Docker image, and incurs a 1-3 second cold start. A Rust binary compiled with PDFluent has no runtime dependency and cold-starts in milliseconds. Build with cargo build --release and copy the single binary to your target.
# Dockerfile (Java / iText)
FROM eclipse-temurin:21-jre
WORKDIR /app
COPY target/myapp.jar .
# ~200 MB JRE layer, 1-3s cold start
ENTRYPOINT ["java", "-jar", "myapp.jar"]# Dockerfile (Rust / PDFluent)
FROM debian:bookworm-slim
WORKDIR /app
COPY target/release/myapp .
# ~20 MB total image, <50ms cold start
ENTRYPOINT ["./myapp"]