高品質 Word ドキュメントを PDF に変換する無料 Java API

documents4j の Maven リポジトリ

// Here’s a commonly used dependency (Local converter): 

<dependency>
<groupId>com.documents4j</groupId>
<artifactId>documents4j-local</artifactId>
<version>1.1.13</version>
</dependency>

//If you only need the API:
<dependency>
<groupId>com.documents4j</groupId>
<artifactId>documents4j-api</artifactId>
<version>1.1.13</version>
</dependency>

GitHub から documents4j をインストール

git clone https://github.com/documents4j/documents4j.git
cd documents4j
cd documents4j-local-demo
mvn jetty:run

Java ライブラリで Word を PDF に変換する方法は？

import com.documents4j.api.DocumentType;
import com.documents4j.api.IConverter;
import com.documents4j.job.LocalConverter;

import java.io.File;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

public class DocumentConverter {
    public static void main(String[] args) {
        // 1. Specify the source and target files
        File wordFile = new File("C:/documents/input.docx");
        File targetFile = new File("C:/documents/output.pdf");

        // 2. Initialize the converter (Local instance)
        IConverter converter = LocalConverter.builder()
                .workerPool(20, 25, 2, TimeUnit.SECONDS)
                .processTimeout(5, TimeUnit.SECONDS)
                .build();

        // 3. Execute the conversion fluently
        boolean success = converter.convert(wordFile).as(DocumentType.MS_WORD)
                                   .to(targetFile).as(DocumentType.PDF)
                                   .execute();

        if (success) {
            System.out.println("Conversion completed successfully!");
        }

        // 4. Always shut down the converter to release native resources
        converter.shutDown();
    }
}

Java アプリ内でリモート Word ドキュメント変換を実行する方法は？

import com.documents4j.api.DocumentType;
import com.documents4j.api.IConverter;
import com.documents4j.job.RemoteConverter;

import java.io.*;
import java.util.concurrent.TimeUnit;

public class RemoteConverterExample {

    public static void main(String[] args) throws Exception {

        // The RemoteConverter connects to the standalone server
        IConverter converter = RemoteConverter.builder()
                .baseFolder(new File("/tmp/documents4j"))
                .workerPool(10, 20, 5, TimeUnit.SECONDS)
                // Timeout for each HTTP conversion request
                .requestTimeout(30, TimeUnit.SECONDS)
                // URI of the running conversion server
                .baseUri("http://192.168.1.100:9998")
                .build();

        // Convert using InputStream / OutputStream — recommended for RemoteConverter
        // because data is already serialized for HTTP transport
        try (InputStream source = new FileInputStream("/input/contract.docx");
             OutputStream target = new FileOutputStream("/output/contract.pdf")) {

            boolean success = converter
                    .convert(source).as(DocumentType.MS_WORD)
                    .to(target).as(DocumentType.PDF)
                    .execute();

            System.out.println("Remote conversion success: " + success);
        }

        converter.shutDown();
    }
}