FileZipEntryTransformer.java

package com.smartandroid.sa.zip.transform;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import com.smartandroid.sa.zip.FileSource;
import com.smartandroid.sa.zip.commons.FileUtils;
import com.smartandroid.sa.zip.commons.IOUtils;

public abstract class FileZipEntryTransformer implements ZipEntryTransformer {

	/**
	 * Copies and transforms the given file into the output file.
	 */
	protected abstract void transform(ZipEntry zipEntry, File in, File out)
			throws IOException;

	public void transform(InputStream in, ZipEntry zipEntry, ZipOutputStream out)
			throws IOException {
		File inFile = null;
		File outFile = null;
		try {
			inFile = File.createTempFile("zip", null);
			outFile = File.createTempFile("zip", null);
			copy(in, inFile);
			transform(zipEntry, inFile, outFile);
			FileSource source = new FileSource(zipEntry.getName(), outFile);
			ZipEntrySourceZipEntryTransformer.addEntry(source, out);
		} finally {
			FileUtils.deleteQuietly(inFile);
			FileUtils.deleteQuietly(outFile);
		}
	}

	private static void copy(InputStream in, File file) throws IOException {
		OutputStream out = new BufferedOutputStream(new FileOutputStream(file));
		try {
			IOUtils.copy(in, out);
		} finally {
			IOUtils.closeQuietly(out);
		}
	}

}