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# OCI Image Packaging
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Specialized packager for exporting fully packaged archives to OCI (Open Container Initiative) images, designed for Docker integration and container deployment workflows.
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## Capabilities
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### ImagePackager
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Creates packaged images from Spring Boot applications, handling the conversion of JAR/WAR archives to OCI-compatible image layers.
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```java { .api }
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/**
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 * Create a new ImagePackager instance
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 * @param source the source file to package
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 * @param backupFile the backup of the source file to package
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 */
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public ImagePackager(File source, File backupFile);
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/**
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 * Create a packaged image using a custom exporter
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 * @param libraries the contained libraries
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 * @param exporter the exporter used to write the image
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 * @throws IOException on IO error
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 */
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public void packageImage(Libraries libraries, BiConsumer<ZipEntry, EntryWriter> exporter) throws IOException;
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```
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**Usage Examples:**
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```java
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import org.springframework.boot.loader.tools.ImagePackager;
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import org.springframework.boot.loader.tools.Libraries;
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import org.springframework.boot.loader.tools.EntryWriter;
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import java.io.File;
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import java.util.zip.ZipEntry;
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import java.util.function.BiConsumer;
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// Create image packager with source and backup
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File sourceJar = new File("myapp.jar");
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File backupJar = new File("myapp.jar.original");
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ImagePackager imagePackager = new ImagePackager(sourceJar, backupJar);
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// Export to OCI image format
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Libraries libraries = /* ... define libraries ... */;
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BiConsumer<ZipEntry, EntryWriter> exporter = (entry, writer) -> {
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    // Custom logic to write entries to OCI image layers
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    System.out.println("Exporting: " + entry.getName());
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    // writer.write(outputStream) to write the entry content
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};
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imagePackager.packageImage(libraries, exporter);
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```
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## Core Types
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```java { .api }
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public interface EntryWriter {
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    void write(OutputStream outputStream) throws IOException;
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    default int size() { return -1; }
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}
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```