Flask接口签名sign原理与实例代码浅析
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2023-01-01
java实现批量下载 多文件打包成zip格式下载
本文实例为大家分享了java实现批量下载的具体代码,供大家参考,具体内容如下
现在的需求的:
根据产品族、产品类型,下载该产品族、产品类型下面的pic包;
pic包是zip压缩文件;
t_product表:
这些包以blob形式存在另一张表中:
t_imagefile表:
现在要做的是:将接入网、OLT下面的两个包downloadPIC:MA5800系列-pic.zip 和 MA5900-pic.rar一起打包成zip压缩文件下载下来;
代码:
ProductController.java:
/**
* 根据产品族、产品类型下载照片包
*/
@RequestMapping("/downloadwBatch")
public void downloadwBatch(HttpServletRequest request, HttpServletResponse response, String productFamily, String productType){
//http://localhost:8080/MySSM/downloadwBatch?productFamily=接入网&productType=OLT
try {
productFamily = new String(productFamily.getBytes("iso-8859-1"), "utf-8");
productType = new String(productType.getBytes("iso-8859-1"), "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
//获取要下载的照片包名
Map
params.put("productFamily", productFamily);
params.put("productType", productType);
List
//根据包名获取待下载的文件 文件名-字节数组的形式
Map
for(String packageName : packageNames){
byte[] f = productService.getPackage(packageName);
if(f!=null){
files.put(packageName, f);
}
}
//设置下载的压缩包名
String zipName = productFamily + "_"+ productType + ".zip";
//根据文件,进行压缩,批量下载
if(files.size() > 0){
productService.downloadBatchByFile(response, files, zipName);
}
}
ProductService.java:
/**
* 根据包名获取文件
*/
public byte[] getPackage(String packageName){
byte[] bag = null;
try{
ImageFile m = productMapper.getPackage(packageName);
if(m!=null){
bag = m.getPicture();
}
}catch(Exception e){
e.printStackTrace();
}
return bag;
}
/**
* 根据产品族、产品类型 获取待下载的包名
* @param params
* @return
*/
public List
List
return packageNames;
}
/**
* 根据文件,进行压缩,批量下载
* @param response
* @param files
* @throws Exception
*/
public void downloadBatchByFile(HttpServletResponse response, Map
try{
response.setContentType("application/x-msdownload");
response.setHeader("content-disposition", "attachment;filename="+URLEncoder.encode(zipName, "utf-8"));
ZipOutputStream zos = new ZipOutputStream(response.getOutputStream());
BufferedOutputStream bos = new BpMdIAXTbufferedOutputStream(zos);
for(Entry
String fileName = entry.getKey(); //每个zip文件名
byte[] file = entry.getValue(); //这个zip文件的字节
BufferedInputStream bis = new BufferedInputStream(new ByteArrayInputStream(file));
zos.putNextEntry(new ZipEntry(fileName));
int len = 0;
byte[] buf = new byte[10 * 1024];
while( (len=bis.read(buf, 0, buf.length)) != -1){
bos.write(buf, 0, len);
}
bis.close();
bos.flush();
}
bos.close();
}catch(Exception e){
e.printStackTrace();
}
}
ProductMapper.java:
/**
* 根据包名获取文件
*/
public ImageFile getPackage(String packageName) throws Exception;
/**
* 据产品族、产品类型 获取待下载的包名
*/
public List
ProductMapper.xml:
select * from t_imagefile where packageName = #{packageName}
select packageName from t_imagefile m join t_product p on m.packageName = p.downloadPic
where p.productFamily = #{productFamily} and p.productType = #{productType}
测试:
在浏览器中输入:http://localhost:8080/MySSM/downloadwBatch?productFamily=接入网&productType=OLT
下载结果如下:
简单的demo
package com.msznyl;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class Download {
public static void main(String[] args) {
//需要压缩的文件--包括文件地址和文件名
String [] path ={"E:\\360DocProtect\\01.txt","E:\\360DocProtect\\02.docx"};
// 要生成的压缩文件地址和文件名称
String desPath = "D:\\DOWNLOADS\\new.zip";
File zipFile = new File(desPath);
ZipOutputStream zipStream = null;
FileInputStream zipSource = null;
BufferedInputStream bufferStream = null;
try {
//构造最终压缩包的输出流
zipStream = new ZipOutputStream(new FileOutputStream(zipFile));
for(int i =0;i File file = new File(path[i]); //将需要压缩的文件格式化为输入流 zipSource = new FileInputStream(file); //压缩条目不是具体独立的文件,而是压缩包文件列表中的列表项,称为条目,就像索引一样 ZipEntry zipEntry = new ZipEntry(file.getName()); //定位该压缩条目位置,开始写入文件到压缩包中 zipStream.putNextEntry(zipEntry); //输入缓冲流 bufferStream = new BufferedInputStream(zipSource, 1024 * 10); int read = 0; //创建读写缓冲区 byte[] buf = new byte[1024 * 10]; while((read = bufferStream.read(buf, 0, 1024 * 10)) != -1) { zipStream.write(buf, 0, read); } } } catch (Exception e) { e.printStackTrace(); } finally { //关闭流 try { if(null != bufferStream) bufferStream.close(); if(null != zipStream) zipStream.close(); if(null != zipSource) zipSource.close(); } catch (IOException e) { e.printStackTrace(); } } } }
File file = new File(path[i]);
//将需要压缩的文件格式化为输入流
zipSource = new FileInputStream(file);
//压缩条目不是具体独立的文件,而是压缩包文件列表中的列表项,称为条目,就像索引一样
ZipEntry zipEntry = new ZipEntry(file.getName());
//定位该压缩条目位置,开始写入文件到压缩包中
zipStream.putNextEntry(zipEntry);
//输入缓冲流
bufferStream = new BufferedInputStream(zipSource, 1024 * 10);
int read = 0;
//创建读写缓冲区
byte[] buf = new byte[1024 * 10];
while((read = bufferStream.read(buf, 0, 1024 * 10)) != -1)
{
zipStream.write(buf, 0, read);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
//关闭流
try {
if(null != bufferStream) bufferStream.close();
if(null != zipStream) zipStream.close();
if(null != zipSource) zipSource.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
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