問題創造了Java多次入境zip文件

Question

任何人都知道什麼是錯，此代碼用於創建包含多個項目

private File zipAttachments(List<File> licenses) throws IOException 
    { 
     byte[] buf = new byte[1024]; 
     File licenseZip = new File("license.zip"); 
     FileOutputStream fos = new FileOutputStream(licenseZip); 
     ZipOutputStream zip = new ZipOutputStream(fos); 
     for(File license:licenses) 
     { 
      ZipEntry zipEntry = new ZipEntry(license.getName()); 
      FileInputStream in = new FileInputStream(license); 
      zip.putNextEntry(zipEntry); 
      int len; 
      while ((len = in.read(buf)) > 0) 
      { 
       zip.write(buf, 0, len); 
      } 
      zip.closeEntry(); 
      in.close(); 
     } 
     zip.close(); 

     return licenseZip; 
    } 

和堆棧中的zip文件是

java.util.zip.ZipException: ZIP file must have at least one entry 
     at java.util.zip.ZipOutputStream.finish(ZipOutputStream.java:304) 
     at java.util.zip.DeflaterOutputStream.close(DeflaterOutputStream.java:146) 
     at java.util.zip.ZipOutputStream.close(ZipOutputStream.java:321) 

但即時通訊相當確定許可證參數不是一個空列表，所以這不意味着我正在創建zip條目？

Answer 1

我想你錯過了這是你的方法的第一行：

if (licenses.isEmpty()) 
    throw new IllegalArgumentException("licenses is empty");