itext pdf验证签名是可见还是不可见 [英] itext pdf verify if signature is visible or invisible
本文介绍了itext pdf验证签名是可见还是不可见的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我目前正在使用Itext 5.4.4,我想知道是否可以检查当前PDF中的签名是可见还是不可见。这可能吗?或者我是否必须升级到更新的Itext版本?
I am currently using Itext 5.4.4 and I would like to know if it is possible to check if a signature in my current PDF is visible or invisible. Is this possible? Or do I have to upgrade to a newer versión of Itext?
推荐答案
您可以像下面的代码那样执行此操作。其他标志很容易添加..
You can do it like the code below. Other flags are easily added..
PdfReader reader; //instantiate
AcroFields acroFields = reader.getAcroFields();
Map<String, Item> fieldNames = acroFields.getFields();
Set<Entry<String, Item>> entries = fieldNames.entrySet();
Iterator<Entry<String, Item>> it = entries.iterator();
while(it.hasNext()){
Entry<String, Item> entry = it.next();
//Check flags
boolean invisible = isInvisible(entry.getValue());
boolean mandatory = isMandatory(entry.getValue());
boolean noView = isNoView(entry.getValue());
boolean hidden = isHidden(entry.getValue());
...
}
public static boolean isInvisible(Item item) {
//Add a nullcheck!
if(item.size()>0) {
PdfDictionary d = item.getMerged(0);
PdfNumber num = (PdfNumber) d.get(PdfName.F);
return num == null ? false : ((num.intValue() & PdfAnnotation.FLAGS_INVISIBLE) == PdfAnnotation.FLAGS_INVISIBLE);
}
return false;
}
public static boolean isMandatory(Item item) {
//Add a null check here!
if(item.size()>0) {
PdfDictionary d = item.getMerged(0);
PdfNumber num = (PdfNumber) d.get(PdfName.FF);
return num == null ? false : ((num.intValue() & PdfFormField.FF_REQUIRED) == PdfFormField.FF_REQUIRED);
}
return false;
}
public static boolean isNoView(Item item) {
//nullcheck!
if(item.size()>0) {
PdfDictionary d = item.getMerged(0);
PdfNumber num = (PdfNumber) d.get(PdfName.F);
return num == null ? false : ((num.intValue() & PdfAnnotation.FLAGS_NOVIEW) == PdfAnnotation.FLAGS_NOVIEW);
}
return false;
}
public static boolean isHidden(Item item) {
//Nullcheck!
if(item.size()>0) {
PdfDictionary d = item.getMerged(0);
PdfNumber num = (PdfNumber) d.get(PdfName.F);
return num == null ? false : ((num.intValue() & PdfAnnotation.FLAGS_HIDDEN) == PdfAnnotation.FLAGS_HIDDEN);
}
return false;
}
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