在前面的章节中介绍了如何利用KeyTool工具生成keyStore：。

但是很多时候，在javaWeb项目中，比如给每个用户加上独特的数字签名，那么我们需要在创建用户的时候，给其生成独一无二的keystore。我现在主要的功能是，给每个用户下载pdf的时候加上数字签名。

下面说一下生成keystore的主要思想：借助keyTool中的生成keyStore的方法。主要利用sun.security.tools.keytool包文件来处理。

import java.io.FileOutputStream;import java.io.IOException;import java.security.GeneralSecurityException;import java.security.KeyStore;import java.security.KeyStoreException;import java.security.NoSuchAlgorithmException;import java.security.PrivateKey;import java.security.cert.CertificateException;import java.security.cert.X509Certificate;import java.util.Date;import sun.security.tools.keytool.CertAndKeyGen;import sun.security.x509.X500Name;/** * 主要用于创建keyStore文件，保存起来 *  * @author Xia * */public class KeyStoreCreate2 {    public static String filePath = "src/main/resources/pdf0090createEncrypt/new_KeyStore.keystore";    private static final int keysize = 1024;    private static final String commonName = "www.ctbri.com";    private static final String organizationalUnit = "IT";    private static final String organization = "test";    private static final String city = "beijing";    private static final String state = "beijing";    private static final String country = "beijing";    private static final long validity = 1096; // 3 years    private static final String alias = "tomcat";    private static final char[] keyPassword = "123456".toCharArray();        public static void main(String[] args) throws GeneralSecurityException {        try {                        KeyStore ks = KeyStore.getInstance("pkcs12");//            char[] password = "123456".toCharArray();            ks.load(null, null);                        CertAndKeyGen keypair = new CertAndKeyGen("RSA", "SHA1WithRSA", null);            X500Name x500Name = new X500Name(commonName, organizationalUnit, organization, city, state, country);            keypair.generate(keysize);                        PrivateKey privateKey = keypair.getPrivateKey();            X509Certificate[] chain = new X509Certificate[1];            chain[0] = keypair.getSelfCertificate(x500Name, new Date(), (long)validity*24*60*60);                        // store away the key store            FileOutputStream fos = new FileOutputStream(filePath);            ks.setKeyEntry(alias, privateKey, keyPassword, chain);            ks.store(fos, keyPassword);            fos.close();            System.out.println("create Success");        } catch (KeyStoreException e) {            e.printStackTrace();        } catch (NoSuchAlgorithmException e) {            e.printStackTrace();        } catch (CertificateException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }    }    }