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:
@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 = new HashMap();
params.put("productFamily", productFamily);
params.put("productType", productType);
List packageNames = productService.getPackageNamesByFamilyAndType(params);
//根据包名获取待下载的文件 文件名-字节数组的形式
Map files = new HashMap();
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:
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;
}
public List getPackageNamesByFamilyAndType(Map params) {
List packageNames = productMapper.getPackageNamesByFamilyAndType(params);
return packageNames;
}
public void downloadBatchByFile(HttpServletResponse response, Map files, String zipName){
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 BufferedOutputStream(zos);
for(Entry entry : files.entrySet()){
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:
public ImageFile getPackage(String packageName) throws Exception; public ListgetPackageNamesByFamilyAndType(Map params);
ProductMapper.xml:
select * from t_imagefile where packageName = #{packageName}
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
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持考高分网。



