批量下载网络图片并zip打包

该功能分为三步:

先把图片下载到本地的一个文件夹

public  void download(String urlString, String filename,String savePath) throws Exception {
// 构造URL
URL url = new URL(urlString);
// 打开连接
URLConnection con = url.openConnection();
//设置请求超时为5s
con.setConnectTimeout(5 * 1000);
// 输入流
InputStream is = con.getInputStream();

// 1K的数据缓冲
byte[] bs = new byte[1024];
// 读取到的数据长度
int len;
// 输出的文件流
File sf=new File(savePath);
if(!sf.exists()){
sf.mkdirs();
}
OutputStream os = new FileOutputStream(sf.getPath()+"\"+filename);
// 开始读取
while ((len = is.read(bs)) != -1) {
os.write(bs, 0, len);
}
// 完毕,关闭所有链接
os.close();
is.close();
}

打包为zip
@RequestMapping(value = "/downZip")
public void downZip(String tcLwIds,HttpServletResponse response) throws Exception {
List<File> files = new ArrayList<File>();
List<String>pathDb=new ArrayList<>();
pathDb.add("group1/M00/00/73/wKgCCFkC56OAbvweAABrRuCppJE685.png");
pathDb.add("group1/M00/00/73/wKgCCFkC56OAYwToAAAuJ6ZQ3Lc233.png");
pathDb.add("group1/M00/00/73/wKgCCFkC56OAQTGpAAAm_2X7-GM329.png");
pathDb.add("group1/M00/00/5D/wKgCD1kC6FCAZxwSAAAm_2X7-GM372.png");
for(int m=0;m<pathDb.size();m++){
String filePath=STORAGE_SERVER_URL+pathDb.get(m);
String fileName=pathDb.get(m).split("/")[4];
String path=test5.class.getResource("/").getFile();
download(filePath, fileName,path);
File file = new File(path+fileName);
files.add(file);
}

String fileName = UUID.randomUUID().toString() + ".zip";
//在服务器端创建打包下载的临时文件
String outFilePath = test5.class.getResource("/").getFile();
createFile(outFilePath,fileName);
File file = new File(outFilePath+fileName);
//文件输出流
FileOutputStream outStream = new FileOutputStream(file);
//压缩流
ZipOutputStream toClient = new ZipOutputStream(outStream);
// toClient.setEncoding("gbk");
zipFile(files, toClient);
toClient.close();
outStream.close();
this.downloadFile(file, response, true);
//删除本地文件
for(File path:files) {
path.delete();
}
}

//创建文件
public void createFile(String path,String fileName){
//path表示你所创建文件的路径
File f = new File(path);
// fileName表示你创建的文件名;为txt类型;
File file = new File(f,fileName);
if(!file.exists()){
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}


}
/** 压缩文件列表中的文件
* @param files
* @param outputStream
* @throws IOException
*/
public static void zipFile(List<File> files, ZipOutputStream outputStream) throws IOException,ServletException
{
try {
int size = files.size();
// 压缩列表中的文件
for (int i = 0; i < size; i++) {
File file =files.get(i);
zipFile(file, outputStream);
}
} catch (IOException e) {
throw e;
}
}
/** 将文件写入到zip文件中
*
* @param inputFile
* @param outputstream
* @throws Exception
*/
public static void zipFile(File inputFile, ZipOutputStream outputstream) throws IOException,ServletException
{
try {
if (inputFile.exists()) {
if (inputFile.isFile()) {
FileInputStream inStream = new FileInputStream(inputFile);
BufferedInputStream bInStream = new BufferedInputStream(
inStream);
ZipEntry entry = new ZipEntry(inputFile.getName());
outputstream.putNextEntry(entry);


final int MAX_BYTE = 10 * 1024 * 1024; // 最大的流为10M
long streamTotal = 0; // 接受流的容量
int streamNum = 0; // 流需要分开的数量
int leaveByte = 0; // 文件剩下的字符数
byte[] inOutbyte; // byte数组接受文件的数据


streamTotal = bInStream.available(); // 通过available方法取得流的最大字符数
streamNum = (int) Math.floor(streamTotal / MAX_BYTE); // 取得流文件需要分开的数量
leaveByte = (int) streamTotal % MAX_BYTE; // 分开文件之后,剩余的数量


if (streamNum > 0) {
for (int j = 0; j < streamNum; ++j) {
inOutbyte = new byte[MAX_BYTE];
// 读入流,保存在byte数组
bInStream.read(inOutbyte, 0, MAX_BYTE);
outputstream.write(inOutbyte, 0, MAX_BYTE); // 写出流
}
}
// 写出剩下的流数据
inOutbyte = new byte[leaveByte];
bInStream.read(inOutbyte, 0, leaveByte);
outputstream.write(inOutbyte);
outputstream.closeEntry(); // Closes the current ZIP entry
// and positions the stream for
// writing the next entry
bInStream.close(); // 关闭
inStream.close();
}
} else {
throw new ServletException("文件不存在!");
}
} catch (IOException e) {
throw e;
}
}


删除存在本地的文件

for(File path:files) {
path.delete();
}

参考:http://takeme.iteye.com/blog/1683380
http://bbs.csdn.net/topics/340174173
http://www.aiisen.com/java-batch-download-photos-zh.html
原文地址:https://www.cnblogs.com/zjn0zjn/p/6797213.html