纯内存读取Zip文件

ゞ浴缸里的玫瑰 2022-06-03 10:55 256阅读 0赞

### 总结 ###

方法1完全内存读取，只需要一个输入流即可；  
方法2必须从操作系统本地读取文件才行，不能做到完全的内存读取；

### 方法1 ###

public static void readZipFile0(InputStream in) throws Exception {
        ZipInputStream zis = new ZipInputStream(in);
        ZipEntry entry = null;
        while ((entry = zis.getNextEntry()) != null) {
            String entryName = entry.getName();
            System.out.println(entryName);
            int size = (int) entry.getSize();
            byte[] buf = new byte[size];
            if (entry.isDirectory()) { 
                //目录
                continue;
            }
            byte[] bs = new byte[1024];
            int len = 0;
            int off = 0;
            while ((len = zis.read(bs)) != -1) {
                System.arraycopy(bs, 0, buf, off, len);
                off += len;
            }
            FileOutputStream out = new FileOutputStream("D:/doc/"+entryName.replace("/", ""));
            out.write(buf);
            out.close();
        }
        zis.close();
    }

### 方法2 ###

public static void readZipFile1(String file) throws Exception {
        ZipFile zf = new ZipFile(file);
        InputStream in = new BufferedInputStream(new FileInputStream(file));
        ZipInputStream zin = new ZipInputStream(in);
        ZipEntry ze = null;
        while ((ze = zin.getNextEntry()) != null) {
            if (ze.isDirectory()) {
                //目录
                continue;
            }
            System.out.println(ze.getName());
            ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
            InputStream fileIn = zf.getInputStream(ze);
            int val;
            while((val=fileIn.read())!=-1) {
                byteOut.write(val);
            }
            fileIn.close();
            byteOut.writeTo(new FileOutputStream("D:/doc/"+ze.getName().replace("/", "")));
            byteOut.close();
        }
        zin.closeEntry();
        zin.close();
        in.close();
        zf.close();
    }