如何用java读取sm2pem文件

要使用Java读取SM2 PEM文件，您可以使用Bouncy Castle库。以下是一个代码示例，可以读取SM2私钥和公钥文件：

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.security.Security;
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.PEMParser;
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;

public class SM2PEMReader {

    public static void main(String[] args) throws IOException {
        Security.addProvider(new BouncyCastleProvider());

        String privateKeyFile = "/path/to/private_key.pem";
        String publicKeyFile = "/path/to/public_key.pem";

        // Read private key
        BufferedReader privateKeyReader = new BufferedReader(new FileReader(privateKeyFile));
        PEMParser pemParser = new PEMParser(privateKeyReader);
        Object object = pemParser.readObject();
        pemParser.close();
        JcaPEMKeyConverter converter = new JcaPEMKeyConverter().setProvider("BC");

        PrivateKeyInfo privateKeyInfo = (PrivateKeyInfo) object;
        System.out.println(converter.getPrivateKey(privateKeyInfo));

        // Read public key
        BufferedReader publicKeyReader = new BufferedReader(new FileReader(publicKeyFile));
        pemParser = new PEMParser(publicKeyReader);
        object = pemParser.readObject();
        pemParser.close();

        SubjectPublicKeyInfo publicKeyInfo = (SubjectPublicKeyInfo) object;
        System.out.println(converter.getPublicKey(publicKeyInfo));
    }
}

请注意，您需要将Bouncy Castle库添加到您的项目中，这里使用了Bouncy Castle API来解析PEM文件。此外，您需要将私钥和公钥文件的路径设置为正确的路径。