Java Java.util.zip.ZipInputStream用法及代碼示例

此類實現一個輸入流過濾器，用於讀取 ZIP 文件格式的文件。包括對壓縮和未壓縮條目的支持。
構造函數：

• ZipInputStream(輸入流中)：創建新的 ZIP 輸入流。
• ZipInputStream(InputStream in, Charset 字符集):創建新的 ZIP 輸入流

方法：

• int available()：當前條目數據到達 EOF 後返回 0，否則始終返回 。
  程序不應指望此方法返回實際字節數
  可以無阻塞地讀取。

  Syntax :public int available()
                throws IOException
  Overrides:
  available in class InflaterInputStream
  返回：
  1 before EOF and 0 after EOF has reached for current entry. 
  Programs should not count on this method to return the actual number 
  of bytes that could be read without blocking.
  Throws:
  IOException 

• 無效close()：關閉此輸入流並釋放與該流關聯的所有係統資源。

  Syntax :public void close()
             throws IOException
  Overrides:
  close in class InflaterInputStream
  Throws:
  IOException

• 無效closeEntry()：關閉當前 ZIP 條目並定位流以讀取下一個條目。

  Syntax :public void closeEntry()
                  throws IOException
  Throws:
  ZipException 
  IOException 

• protected ZipEntry createZipEntry(字符串名稱):為指定條目名稱創建新的ZipEntry對象。

  Syntax :protected ZipEntry createZipEntry(String name)
  參數：
  name - the ZIP file entry name
  返回：
  the ZipEntry just created

• ZipEntry getNextEntry()：讀取下一個 ZIP 文件條目並將流定位在條目數據的開頭。

  Syntax :public ZipEntry getNextEntry()
                        throws IOException
  返回：
  the next ZIP file entry, or null if there are no more entries
  Throws:
  ZipException 
  IOException 

• int 讀取(字節[] b，int 關閉，int len)：從當前 ZIP 條目讀取到字節數組中。如果 len 不為零，則該方法將阻塞，直到某些輸入可用為止；否則，不會讀取任何字節並返回 0。

  Syntax :public int read(byte[] b,
         int off,
         int len)
           throws IOException
  參數：
  b - the buffer into which the data is read
  off - the start offset in the destination array b
  len - the maximum number of bytes read
  返回：
  the actual number of bytes read, or -1 if the end of the entry is reached
  Throws:
  NullPointerException 
  IndexOutOfBoundsException 
  ZipException 
  IOException

• 長跳過(長n)：跳過當前 ZIP 條目中指定的字節數。

  Syntax :public long skip(long n)
            throws IOException
  參數：
  n - the number of bytes to skip
  返回：
  the actual number of bytes skipped
  Throws:
  ZipException
  IOException
  IllegalArgumentException 

//Java program demonstrating ZipInputStream methods 
  
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.util.Arrays; 
import java.util.jar.JarInputStream; 
import java.util.zip.ZipEntry; 
import java.util.zip.ZipInputStream; 
class ZipInputStreamDemo extends ZipInputStream 
{ 
    public ZipInputStreamDemo(InputStream in)  
    { 
        super(in); 
    } 
  
    public static void main(String[] args) throws IOException 
    { 
        FileInputStream fis = new FileInputStream("Awesome CV.zip"); 
        ZipInputStream zis = new JarInputStream(fis); 
        ZipInputStreamDemo obj = new ZipInputStreamDemo(zis); 
  
        //illustrating createZipEntry() 
        ZipEntry ze = obj.createZipEntry("ZipEntry"); 
        System.out.println(ze.getName()); 
  
        //illustrating getNextEntry() 
        ZipEntry je = zis.getNextEntry(); 
        System.out.println(je.getName()); 
  
        //illustrating skip() method 
        zis.skip(3); 
  
        //illustrating closeEntry() method 
        zis.closeEntry(); 
        zis.getNextEntry(); 
        byte b[] = new byte[10]; 
  
        //illustrating available() method 
        //Reads up to byte.length bytes of data from this input stream 
        if(zis.available() == 1) 
            zis.read(b); 
        System.out.println(Arrays.toString(b)); 
  
        //closing the stream 
        zis.close(); 
    } 
} 

輸出：

ZipEntry
awesome-cv.cls
[35, 32, 65, 119, 101, 115, 111, 109, 101, 32]