运用场景：大文件输出效率低，需要压缩文件以缩短运行时间提高体验。
文件压缩方法工具（参考链接：http://www.manongjc.com/article/4206.html）
/**
* 压缩文件和文件夹（SDCard文件压缩）
* http://www.manongjc.com/article/4206.html
*
* @param srcFile 要压缩的文件或文件夹
* @param zipFile 压缩完成的Zip文件
* @throws Exception
*/
public static void ZipFolder(File srcFile, File zipFile) {
try {
//创建ZIP
ZipOutputStream outZip = new ZipOutputStream(new FileOutputStream(zipFile));
//压缩
ZipFiles(srcFile.getParent() + File.separator, srcFile.getName(), outZip);
//完成和关闭
outZip.finish();
outZip.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 压缩文件
*
* @param srcFileParentName
* @param srcFileName
* @param zipOutputSteam
* @throws Exception
*/
private static void ZipFiles(String srcFileParentName, String srcFileName, ZipOutputStream zipOutputSteam) throws Exception {
if (zipOutputSteam == null)
return;
File file = new File(srcFileParentName + srcFileName);
if (file.isFile()) {
ZipEntry zipEntry = new ZipEntry(srcFileName);
FileInputStream inputStream = new FileInputStream(file);
zipOutputSteam.putNextEntry(zipEntry);
int len;
byte[] buffer = new byte[1024 * 1024 * 10]; //10M
while ((len = inputStream.read(buffer)) != -1) {
zipOutputSteam.write(buffer, 0, len);
}
zipOutputSteam.closeEntry();
} else {
//文件夹
String fileList[] = file.list();
//没有子文件和压缩
if (fileList.length <= 0) {
ZipEntry zipEntry = new ZipEntry(srcFileName + File.separator);
zipOutputSteam.putNextEntry(zipEntry);
zipOutputSteam.closeEntry();
}
//子文件和递归
for (int i = 0; i < fileList.length; i++) {
if (USBMTPReceiver.isCanceled || !USBMTPReceiver.isRunning) break;
ZipFiles(srcFileParentName + srcFileName + "/", fileList[i], zipOutputSteam);
double progress = DialogUtils.getProgress(i + 1, fileList.length);
EventBus.getDefault().post("zipFile&" + progress);
}
}
}
Usb文件的压缩（两种方法实现）
方法一：仿以上方法实现压缩（直接对Usb文件压缩，一步到位，但是耗时多）
/**
* 压缩文件和文件夹（usb文件压缩）
*
* @param srcFile 要压缩的文件或文件夹
* @param zipFile 压缩完成的Zip文件
* @throws Exception
*/
public static void ZipUsbFolder(UsbFile srcFile, UsbFile zipFile) throws Exception {
//创建ZIP
ZipOutputStream outZip = new ZipOutputStream(new UsbFileOutputStream(zipFile));
//压缩
Log.i("whh0923", "srcFile=" + srcFile.getParent() + ",zipFile=" + zipFile.getName());
ZipUsbFiles(srcFile, outZip);
//完成和关闭
outZip.finish();
outZip.close();
}
/**
* 压缩文件
*
* @param srcFile
* @param zipOutputSteam
* @throws Exception
*/
private static void ZipUsbFiles(UsbFile srcFile, ZipOutputStream zipOutputSteam) throws Exception {
Log.i("whh0923", "srcFileName:" + srcFile.getName());
if (zipOutputSteam == null)
return;
if (!srcFile.isDirectory()) {
ZipEntry zipEntry = new ZipEntry(srcFile.getName());
UsbFileInputStream inputStream = new UsbFileInputStream(srcFile);
zipOutputSteam.putNextEntry(zipEntry);
int len;
byte[] buffer = new byte[4096];
while ((len = inputStream.read(buffer)) != -1) {
zipOutputSteam.write(buffer, 0, len);
}
zipOutputSteam.closeEntry();
} else {
//文件夹
UsbFile[] usbFiles = srcFile.listFiles();
//没有子文件和压缩
if (usbFiles.length <= 0) {
ZipEntry zipEntry = new ZipEntry(srcFile.getName() + File.separator);
zipOutputSteam.putNextEntry(zipEntry);
zipOutputSteam.closeEntry();
}
//子文件和递归
for (int i = 0; i < usbFiles.length; i++) {
ZipUsbFiles(usbFiles[i], zipOutputSteam);
}
}
}
方法二：通过上述方法将压缩文件暂存SDCard，再拷贝到U盘（流程多，但效率高）
SDCard zip文件拷贝到USB设备方法
/**
* 拷贝文件到USB设备(以每20M的速度传输)
* @param file SDcard文件
* @param usbFile USB文件
*/
public static void copyFile(File file, UsbFile usbFile) {
FileInputStream inStream = null;
try {
inStream = new FileInputStream(file);
UsbFileOutputStream outStream = new UsbFileOutputStream(usbFile);
byte[] buf = new byte[1024 * 1024 * 20]; //20M
int len;
while ((len = inStream.read(buf)) > 0) {
outStream.write(buf, 0, len);
}
outStream.close();
inStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
解压文件
public static String tempFileName = "/sdcard/GADataTemp"; //临时文件夹名
/**
* 解压zip压缩文件到指定目录
*
* @param zipPath
*/
public static boolean unzipFile(String zipPath) {
try {
Log.e("whh0927", "开始解压的文件：" + zipPath + "," + "解压的目标路径：" + tempFileName);
// 创建解压目标目录
File file = new File(tempFileName);
// 如果目标目录不存在，则创建
if (!file.exists()) {
file.mkdirs();
}
// 打开压缩文件
InputStream inputStream = new FileInputStream(zipPath);
ZipInputStream zipInputStream = new ZipInputStream(inputStream);
// 读取一个进入点
ZipEntry zipEntry = zipInputStream.getNextEntry();
// 使用1Mbuffer
byte[] buffer = new byte[1024 * 1024];
// 解压时字节计数
int count = 0;
// 如果进入点为空说明已经遍历完所有压缩包中文件和目录
while (zipEntry != null) {
// Log.e("whh0927", "解压文件 入口 1： " + zipEntry);
if (!zipEntry.isDirectory()) { //如果是一个文件
// 如果是文件
String fileName = zipEntry.getName();
// Log.e("whh0927", "解压文件 原来 文件的位置： " + fileName);
fileName = fileName.substring(fileName.lastIndexOf("/") + 1); //截取文件的名字 去掉原文件夹名字
// Log.e("whh0927", "解压文件 的名字： " + fileName);
file = new File(tempFileName + File.separator + fileName); //放到新的解压的文件路径
file.createNewFile();
FileOutputStream fileOutputStream = new FileOutputStream(file);
while ((count = zipInputStream.read(buffer)) > 0) {
fileOutputStream.write(buffer, 0, count);
}
fileOutputStream.close();
}
// 定位到下一个文件入口
zipEntry = zipInputStream.getNextEntry();
// Log.e("whh0927", "解压文件 入口 2： " + zipEntry);
}
zipInputStream.close();
FileUtils.deleteFile(new File(zipPath)); //删除原文件
return true;
} catch (Exception e) {
e.printStackTrace();
Log.e("whh0927", "unzipFile Exception" + e.toString());
return false;
}
}
每天进步一点点。。。（2019-10-09）