Java

有个需求，说要在生成PDF文件时加上signature。
操作PDF容易,用:

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.1.3</version>
</dependency>

加个signature可以用这个方法:

public static PdfStamper createSignature(final PdfReader reader, final OutputStream os, final char pdfVersion){..}

然后我用PdfStamper对象.getSignatureAppearance()获得一个PdfSignatureAppearance再给他setCrypto...

    /**
     * Sets the cryptographic parameters.
     * @param privKey the private key
     * @param certChain the certificate chain
     * @param crlList the certificate revocation list. It may be null
     * @param filter the cryptographic filter type. It can be SELF_SIGNED, VERISIGN_SIGNED or WINCER_SIGNED
     */
    public void setCrypto(PrivateKey privKey, Certificate[] certChain, CRL[] crlList, PdfName filter) {
        this.privKey = privKey;
        this.certChain = certChain;
        this.crlList = crlList;
        this.filter = filter;
    }

参数列表的前两个东西我需要从KeyStore中得到....
KeyStore...java.security.KeyStore...

String mypassword = "hehe";
KeyStore ks_ = KeyStore.getInstance("JKS");
ks_.store(new FileOutputStream("papa.keystore"),mypassword.toCharArray());

但是却提示:
Exception in thread "main" java.security.KeyStoreException: Uninitialized keystore

那怎么才算initialized?

if (!initialized) {
    throw new KeyStoreException("Uninitialized keystore");
}

我们需要一个文件!

public final void load(InputStream stream, char[] password) throws IOException,NoSuchAlgorithmException, CertificateException {
    keyStoreSpi.engineLoad(stream, password);
    initialized = true;
}

在此记录一下windows下生成keystore文件的方法...

先到我的JDK的bin目录下找keytool
输入keytool -genkey -alias hehe.keystore -keystore hehe.keystore,然后按提示走:

按提示再输入两次口令后发现生成了一个.keystore，可以拿来用了。

String PASSWORD = "papa";
KeyStore ks = KeyStore.getInstance("jks");
ks.load(new FileInputStream("hehe.keystore"), PASSWORD.toCharArray());
String alias = (String)ks.aliases().nextElement();
PrivateKey key = (PrivateKey)ks.getKey(alias, PASSWORD.toCharArray());
Certificate[] chain = ks.getCertificateChain(alias);