Java文档的页数

Question

我有一个pdf文档的base64和byte[]，我需要从文档的这个页数中获得如何做到这一点。

PdfReader reader = Here my question 
int ret = reader.getNumberOfPages();

Answer 1

您的问题不太清楚。你有base64编码的byte[]是什么意思？通常，您有一个base64编码的字符串或一个byte[]。

import java.util.Base64;
//[...]
String yourBase64encodedPdf = "JVBERi0xLjIgCjkgMCBvYmoKPDwKPj4Kc3RyZWFtCkJULyA5IFRmKFRlc3QpJyBFVAplbmRzdHJlYW0KZW5kb2JqCjQgMCBvYmoKPDwKL1R5cGUgL1BhZ2UKL1BhcmVudCA1IDAgUgovQ29udGVudHMgOSAwIFIKPj4KZW5kb2JqCjUgMCBvYmoKPDwKL0tpZHMgWzQgMCBSIF0KL0NvdW50IDEKL1R5cGUgL1BhZ2VzCi9NZWRpYUJveCBbIDAgMCA5OSA5IF0KPj4KZW5kb2JqCjMgMCBvYmoKPDwKL1BhZ2VzIDUgMCBSCi9UeXBlIC9DYXRhbG9nCj4+CmVuZG9iagp0cmFpbGVyCjw8Ci9Sb290IDMgMCBSCj4+CiUlRU9G";
//do this if it is base64 encoded otherwise directly use the byte[]
byte[] decodedPdf = Base64.getDecoder().decode(yourBase64encodedPdf);
PdfReader reader = new PdfReader(decodedPdf);
int numOfPages = reader.getNumberOfPages();