压缩包在内存中添加文件,并直接输出

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ApkUtil {
    
	private static final Logger logger = LoggerFactory.getLogger(ApkUtil.class);
	private static final byte[] sourceApkBytes = initializeSourceApk();
	
	private ApkUtil(){}
	private static byte[] initializeSourceApk() {
		String sourceApkPath = ApkUtil.class.getResource("/app/ZHXS.apk").getPath();
		byte[] tmpBytes = new byte[1024];
		File apkFile = new File(sourceApkPath);
		ByteArrayOutputStream apkOut = new ByteArrayOutputStream();
		FileInputStream apkFis = null;
		try {
			apkFis = new FileInputStream(apkFile);
			int b = 0;
			while ((b = apkFis.read(tmpBytes)) != -1) {
				apkOut.write(tmpBytes, 0, b);
			}
			return apkOut.toByteArray();
		} catch (Exception e) {
			logger.error(e.getMessage() ,e);
		} finally {
			closeInputStream(apkFis);
			closeOutputStream(apkOut);
		}
		return null;
	}
    
	private static void closeOutputStream(OutputStream outputStream) {
		if (outputStream != null) {
			try {
				outputStream.close();
			} catch (IOException e) {
				logger.error(e.getMessage(), e);
			}
		}
	}
	
	private static void closeInputStream(InputStream inputStream) {
		if (inputStream != null) {
			try {
				inputStream.close();
			} catch (IOException e) {
				logger.error(e.getMessage(), e);
			}
		}
	}
    
	public static byte[] addFilesToExistingZip(String fileName) throws IOException {
		
		ByteArrayOutputStream finalByteArrayOutputStream = new ByteArrayOutputStream();
		ZipOutputStream zipOutputStrem = new ZipOutputStream(finalByteArrayOutputStream);
		
		ZipInputStream zipInputStream = new ZipInputStream(new ByteArrayInputStream(sourceApkBytes));
		ZipEntry entry = zipInputStream.getNextEntry();
		byte[] buf = new byte[1024];
		while (entry != null) {
			String name = entry.getName();
			zipOutputStrem.putNextEntry(new ZipEntry(name));
			int len;
			while ((len = zipInputStream.read(buf)) > 0) {
				zipOutputStrem.write(buf, 0, len);
			}
			entry = zipInputStream.getNextEntry();
		}
		closeInputStream(zipInputStream);
		
        if (StringUtils.isNotBlank(fileName)) {
        	zipOutputStrem.putNextEntry(new ZipEntry("META-INF/" + fileName));
        }
		zipOutputStrem.closeEntry();
		closeOutputStream(zipOutputStrem);
		return finalByteArrayOutputStream.toByteArray();
	}
		
	public static void downloadApk(String fileName, HttpServletResponse response) {
		ServletOutputStream output = null;
		try {
			output = response.getOutputStream();
			byte[] bytes = null;
			if (StringUtils.isNotBlank(fileName)) {
				bytes = addFilesToExistingZip(fileName);
			} else {
				bytes = sourceApkBytes;
			}
			output.write(bytes);
		} catch (IOException e) {
			logger.error("Failed to download" + fileName + "apk");
		} finally {
			closeOutputStream(output);
		}
	}
	
	public static void main(String[] args) {
		try {
			byte[] bytes = addFilesToExistingZip("zhxs_2699_"+URLEncoder.encode("测试", "utf-8"));
			String targetDir = ApkUtil.class.getResource("/app/").getPath();
			// 输出
			FileOutputStream outt = new FileOutputStream(new File(targetDir + "zhxs_2699.apk"));
			outt.write(bytes);
			outt.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}