分享非常有用的Java程序 (关键代码) (三)---创建ZIP和JAR文件

import java.util.zip.*;   

import java.io.*;       
public class ZipIt {       
	public static void main(String args[]) throws IOException { 
		if (args.length < 2) {              
			System.err.println("usage: java ZipIt Zip.zip file1 file2 file3");               
			System.exit(-1);           
			}           
		File zipFile = new File(args[0]);           
		if (zipFile.exists()) {               
			System.err.println("Zip file already exists, please try another");
			System.exit(-2);          
			}           
		FileOutputStream fos = new FileOutputStream(zipFile);           
		ZipOutputStream zos = new ZipOutputStream(fos);           
		int bytesRead;           
		byte[] buffer = new byte[1024];           
		CRC32 crc = new CRC32();           
		for (int i=1, n=args.length; i < n; i++) {               
			String name = args[i];               
			File file = new File(name);               
			if (!file.exists()) {                   
				System.err.println("Skipping: " + name);                   
				continue;               
				}               
			BufferedInputStream bis = new BufferedInputStream( new FileInputStream(file));               
			crc.reset();               
			while ((bytesRead = bis.read(buffer)) != -1) {                   
				crc.update(buffer, 0, bytesRead);               
				}               
			bis.close();               
				// Reset to beginning of input stream               
			bis = new BufferedInputStream(new FileInputStream(file));               
			ZipEntry entry = new ZipEntry(name);               
			entry.setMethod(ZipEntry.STORED);              
			entry.setCompressedSize(file.length());               
			entry.setSize(file.length());               
			entry.setCrc(crc.getValue());               
			zos.putNextEntry(entry);              
			while ((bytesRead = bis.read(buffer)) != -1) {                   
				zos.write(buffer, 0, bytesRead);              
				}               bis.close();           
				}           
		zos.close();       
				}   
	} 
		}
	}
}