在windows环境下进行的测试，前提条件，windows上需要先安装openssl。

配置环境变量，查看版本：

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")); }}

对应目录下可以生成：

其中，ca.crt是自签名证书文件。ca.key是私钥。ca.csr只是生成证书的中间请求，是用来指定一些信息，这边只指定国家为CN。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。