Java如何基于command调用openssl生成私钥证书

import java.io.*;
import java.util.Properties;

public class OpensslCommand {
  private static void runCMD(String[] CMD) {
    java.lang.Process process = null;
    try {
      process = Runtime.getRuntime().exec(CMD);
      ByteArrayOutputStream resultOutStream = new ByteArrayOutputStream();
      InputStream errorInStream = new BufferedInputStream(process.getErrorStream());
      InputStream processInStream = new BufferedInputStream(process.getInputStream());
      int num = 0;
      byte[] bs = new byte[1024];
      while ((num = errorInStream.read(bs)) != -1) {
        resultOutStream.write(bs, 0, num);
      }
      while ((num = processInStream.read(bs)) != -1) {
        resultOutStream.write(bs, 0, num);
      }
      String result = new String(resultOutStream.toByteArray(), "gbk");
      System.out.println(result);
      errorInStream.close();
      processInStream.close();
      resultOutStream.close();
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      if (process != null) process.destroy();
    }
  }
  public static void main(String[] args) throws Exception {
    //需要指定openssl.exe路径
    //java生成私钥
    String[] cmdPrivateKey = {"cmd", "/C", "C:\\soft\\OpenSSL-Win64\\bin\\openssl.exe genrsa -out ca.key 2048"};
    //java生成证书请求
    String[] cmdCertificationReq = {"cmd", "/C", "C:\\soft\\OpenSSL-Win64\\bin\\openssl.exe req -new -key ca.key -out ca.csr -subj /C=CN"};
    //java生成证书
    String[] cmdCertification = {"cmd", "/C", "C:\\soft\\OpenSSL-Win64\\bin\\openssl.exe x509 -req -days 365 -in ca.csr -signkey ca.key -out ca.crt"};
    runCMD(cmdPrivateKey);
    runCMD(cmdCertificationReq);
    runCMD(cmdCertification);
    Properties props=System.getProperties(); //系统属性
    System.out.println("用户的当前工作目录："+props.getProperty("user.dir"));
  }
}