[Java] 使用ZipInputStream決議zip類檔案（jar、docx）的范例

作者： zyl910

一、緣由

現在zip類的檔案越來越多了，例如jar、docx，
有時我們需批量處理這些檔案中的資料，若都是手工操作的話就太麻煩了，于是考慮編程自動處理，
Java提供了ZipInputStream等zip的操作類，但是有些內容比較抽象，沒有代碼范例的話有點難以理解，例如zip中的目錄究竟是什么，
于是我做個個Demo來演示如何用它來決議zip檔案，輸出資訊，

二、原始碼

import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class ZipReadTest {
    public static void main(String[] args) {
        String srcPath = "target/classes/static/test.docx";
        try(FileInputStream is = new FileInputStream(srcPath)) {
            run(System.out, is);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println("ZipReadTest done.");
    }

    private static void run(PrintStream out, InputStream is) throws IOException {
        try(ZipInputStream zis = new ZipInputStream(is)) {
            ZipEntry zipEntry;
            while ((zipEntry = zis.getNextEntry()) != null) {
                if (null==zipEntry) continue;
                String line = String.format("ZipEntry(%s, isDirectory=%d, size=%d, compressedSize=%d, time=%d, crc=%d, method=%d, comment=%s)",
                        zipEntry.getName(), (zipEntry.isDirectory())?1:0, zipEntry.getSize(), zipEntry.getCompressedSize(), zipEntry.getTime(), zipEntry.getCrc(), zipEntry.getMethod(), zipEntry.getComment());
                out.println(line);
            }
        }
    }
}

三、測驗結果

對一個docx檔案進行處理，測驗結果如下：

ZipEntry([Content_Types].xml, isDirectory=0, size=1344, compressedSize=354, time=312739200000, crc=1239027019, method=8, comment=null)
ZipEntry(docProps/app.xml, isDirectory=0, size=289, compressedSize=183, time=312739200000, crc=4091958464, method=8, comment=null)
ZipEntry(docProps/core.xml, isDirectory=0, size=392, compressedSize=220, time=312739200000, crc=3065131828, method=8, comment=null)
ZipEntry(word/document.xml, isDirectory=0, size=36724, compressedSize=4017, time=312739200000, crc=1830572178, method=8, comment=null)
ZipEntry(word/fontTable.xml, isDirectory=0, size=2120, compressedSize=398, time=312739200000, crc=268271083, method=8, comment=null)
ZipEntry(word/numbering.xml, isDirectory=0, size=2868, compressedSize=502, time=312739200000, crc=3349595521, method=8, comment=null)
ZipEntry(word/settings.xml, isDirectory=0, size=815, compressedSize=325, time=312739200000, crc=773262145, method=8, comment=null)
ZipEntry(word/styles.xml, isDirectory=0, size=8628, compressedSize=1319, time=312739200000, crc=2957985579, method=8, comment=null)
ZipEntry(_rels/.rels, isDirectory=0, size=588, compressedSize=228, time=312739200000, crc=1578830051, method=8, comment=null)
ZipEntry(word/media/image1.emf, isDirectory=0, size=881176, compressedSize=97920, time=312739200000, crc=1974652776, method=8, comment=null)
ZipEntry(word/_rels/document.xml.rels, isDirectory=0, size=980, compressedSize=283, time=312739200000, crc=2086150245, method=8, comment=null)
ZipReadTest done.

以上就是docx內的檔案結構，

平時使用WinZip等檔案來查看zip類檔案時，是顯示為樹形結構，但是在zip檔案中實際上記錄的是相對路徑，
zip檔案類一般不用記錄目錄，只記錄相對路徑就行，
當需要記錄目錄時，ZipEntry的name以分隔符結尾（如 word/），相關資料流為空，

參考文獻

• Javadoc《Class ZipInputStream》. https://docs.oracle.com/javase/8/docs/api/index.html?java/util/zip/ZipInputStream.html

標籤：Java

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