不解压直接读取压缩包中的文件

来源：互联网发布：淘宝子账号权重值500 编辑：程序博客网时间：2024/05/18 03:42

项目中需要用到不解压压缩包，直接读取压缩包中的文件，于是研究下了，现整理出来。

读取指定文件有两种思路，一种是在循环中遍历进行判断，另一种是直接通过文件名进行获取；

通过文件名直接获取
使用zipFile.getEntry(“文件名”)方法获取

public static void readZipFile1(String file,String fileName) throws Exception {          ZipFile zf = new ZipFile(file);        ZipEntry ze = zf.getEntry(fileName);        InputStream in = zf.getInputStream(ze);        BufferedReader br = new BufferedReader(new InputStreamReader(in));        String line;        StringBuffer result = new StringBuffer();        while ((line = br.readLine()) != null) {          result.append(line+"\n");    }        System.out.println(result);}

循环遍历中根据文件名进行判断

public static void readZipFile2(String file,String fileName) throws Exception {          ZipFile zf = new ZipFile(file);          InputStream in = new BufferedInputStream(new FileInputStream(file));          ZipInputStream zin = new ZipInputStream(in);          ZipEntry ze;        StringBuffer result = new StringBuffer();        while ((ze = zin.getNextEntry()) != null) {              if (ze.isDirectory()) {               continue;            } else {                  long size = ze.getSize();                String name = ze.getName();                if (size > 0 && fileName.equals(name)) {                      BufferedReader br = new BufferedReader(new InputStreamReader(zf.getInputStream(ze)));                    String line;                      while ((line = br.readLine()) != null) {                          result.append(line+"\n");                    }                      br.close();                  }              }          }        System.out.println(result);        zin.closeEntry();  }

public static void readZipFile3(String file, String fileName) {          try {              ZipFile zipFile = new ZipFile(file);             StringBuffer result = new StringBuffer();            Enumeration<ZipEntry> enu = (Enumeration<ZipEntry>) zipFile.entries();              while (enu.hasMoreElements()) {                  ZipEntry zipElement = (ZipEntry) enu.nextElement();                  InputStream read = zipFile.getInputStream(zipElement);                  String name = zipElement.getName();                  if (name != null && fileName.equals(name)) {                    BufferedReader br = new BufferedReader(new InputStreamReader(read));                    String line;                      while ((line = br.readLine()) != null) {                          result.append(line+"\n");                    }                      br.close();                }              }        } catch (Exception e) {              e.printStackTrace();          }  }

在main方法中调用

public static void main(String[] args) throws Exception {    readZipFile("G://report.zip", "1004165931.html");}

通过上面的几种方法可以实现直接从有压缩包中读取指定文件，当然我们也可以把指定文件写入到指定目录中再打开，实现代码如下：

/**  *   * @param file 压缩包路径  * @param saveRootDirectory 写入文件夹路径  * @param fileName 文件名  * @throws FileNotFoundException  * @throws IOException  */public static void writeZipFile(String file,String saveRootDirectory,String fileName) throws FileNotFoundException, IOException {        int len = 0;        ZipFile zf = new ZipFile(file);        ZipEntry ze = zf.getEntry(fileName);        InputStream read = zf.getInputStream(ze);        File writeFile = new File(saveRootDirectory + fileName);        if (!writeFile.exists()) {              File rootDirectoryFile = new File(saveRootDirectory);              //创建目录              if (!rootDirectoryFile.exists()) {                  rootDirectoryFile.mkdirs();              }             //创建文件              writeFile.createNewFile();            BufferedOutputStream write = new BufferedOutputStream(new FileOutputStream(file));            //写入文件内容            while ((len = read.read()) != -1) {                write.write(len);            }            write.flush();              write.close();          }        read.close();  }

上面的代码实现了，把file路径下的压缩包中的名为fileName的文件写入到saveRootDirectory目录下。

0 0