Java Java.util.zip.ZipInputStream用法及代码示例

此类实现一个输入流过滤器，用于读取 ZIP 文件格式的文件。包括对压缩和未压缩条目的支持。
构造函数：

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

方法：

• int available()：当前条目数据到达 EOF 后返回 0，否则始终返回 。
  程序不应指望此方法返回实际字节数
  可以无阻塞地读取。

  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 

• 无效close()：关闭此输入流并释放与该流关联的所有系统资源。

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

• 无效closeEntry()：关闭当前 ZIP 条目并定位流以读取下一个条目。

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

• protected ZipEntry createZipEntry(字符串名称):为指定条目名称创建新的ZipEntry对象。

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

• ZipEntry getNextEntry()：读取下一个 ZIP 文件条目并将流定位在条目数据的开头。

  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 读取(字节[] b，int 关闭，int len)：从当前 ZIP 条目读取到字节数组中。如果 len 不为零，则该方法将阻塞，直到某些输入可用为止；否则，不会读取任何字节并返回 0。

  Syntax :public int read(byte[] b,
         int off,
         int len)
           throws IOException
  参数：
  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

• 长跳过(长n)：跳过当前 ZIP 条目中指定的字节数。

  Syntax :public long skip(long n)
            throws IOException
  参数：
  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(); 
    } 
} 

输出：

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