多个BufferedInputStream流合并成一个压缩流返回给前端一个zip文件

可以使用Java的ZipOutputStream类来创建压缩文件。具体实现步骤如下：

1. 创建一个ZipOutputStream对象，并指定输出流为要返回给前端的输出流。

OutputStream out = new BufferedOutputStream(response.getOutputStream());
ZipOutputStream zipOut = new ZipOutputStream(out);

2. 遍历所有的BufferedInputStream流，将每个文件压缩成一个ZipEntry对象，并将其添加到ZipOutputStream对象中。

for (BufferedInputStream in : inputStreamList) {
    ZipEntry entry = new ZipEntry("file" + i + ".txt");
    zipOut.putNextEntry(entry);
    byte[] buffer = new byte[1024];
    int len;
    while ((len = in.read(buffer)) > 0) {
        zipOut.write(buffer, 0, len);
    }
    zipOut.closeEntry();
    i++;
}

3. 关闭ZipOutputStream和输出流。

zipOut.close();
out.close();

完整代码示例：

OutputStream out = new BufferedOutputStream(response.getOutputStream());
ZipOutputStream zipOut = new ZipOutputStream(out);
List<BufferedInputStream> inputStreamList = new ArrayList<>();

// 添加所有的BufferedInputStream流
// ...

try {
    int i = 1;
    for (BufferedInputStream in : inputStreamList) {
        ZipEntry entry = new ZipEntry("file" + i + ".txt");
        zipOut.putNextEntry(entry);
        byte[] buffer = new byte[1024];
        int len;
        while ((len = in.read(buffer)) > 0) {
            zipOut.write(buffer, 0, len);
        }
        zipOut.closeEntry();
        i++;
    }
    zipOut.close();
    out.close();
} catch (IOException e) {
    e.printStackTrace();
}