RestTemplate进行https请求时适配信任证书

转载请注明出处：

1.http协议请求

　　使用RestTemplate进行http协议的请求时，不需要考虑证书验证相关问题，以下为使用RestTemplate直接使用的代码示例：

import org.springframework.web.client.RestTemplate;  
import org.springframework.http.ResponseEntity;  
import org.springframework.http.HttpMethod;  
import org.springframework.http.HttpEntity;  
import org.springframework.http.HttpHeaders;  
  
public class HttpRestClient {  
  
    public static void main(String[] args) {  
        RestTemplate restTemplate = new RestTemplate();  
  
        String url = "http://example.com/api/endpoint"; // 注意这里是HTTP协议  
        HttpHeaders headers = new HttpHeaders();  
        // 可以在这里添加请求头，如果需要的话  
        HttpEntity<?> requestEntity = new HttpEntity<>(headers);  
  
        try {  
            ResponseEntity<String> responseEntity = restTemplate.exchange(  
                url,  
                HttpMethod.GET, // 或者使用其他HTTP方法，如POST、PUT等  
                requestEntity,  
                String.class // 指定响应体的类型  
            );  
  
            // 处理响应  
            if (responseEntity.getStatusCode().is2xxSuccessful()) {  
                String responseBody = responseEntity.getBody();  
                System.out.println("Response: " + responseBody);  
            } else {  
                System.out.println("Request failed with status: " + responseEntity.getStatusCode());  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
}

2.Https请求信任所有证书：

　　在Java中，使用RestTemplate进行HTTP请求时，默认情况下它会验证HTTPS证书的有效性。如果想要忽略HTTPS证书验证（这通常不推荐，因为它会降低安全性），需要自定义一个HttpClient并设置它忽略SSL证书验证。

　　以下是一个示例，展示了如何为RestTemplate创建一个自定义的HttpClient，该HttpClient将忽略HTTPS证书验证：

1. 创建一个忽略SSL证书验证的HttpClient：

import org.apache.http.conn.ssl.NoopHostnameVerifier;  
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;  
import org.apache.http.impl.client.CloseableHttpClient;  
import org.apache.http.impl.client.HttpClients;  
import org.apache.http.ssl.SSLContexts;  
import javax.net.ssl.SSLContext;  
import java.security.KeyManagementException;  
import java.security.NoSuchAlgorithmException;  
  
public CloseableHttpClient createTrustingHttpClient() throws NoSuchAlgorithmException, KeyManagementException {  
    SSLContext sslContext = SSLContexts.custom()  
            .loadTrustMaterial(null, (chain, authType) -> true) // 信任所有证书  
            .build();  
  
    SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, NoopHostnameVerifier.INSTANCE);  
  
    return HttpClients.custom()  
            .setSSLSocketFactory(sslsf)  
            .build();  
}

　　2.使用自定义的HttpClient创建RestTemplate：

import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;  
import org.springframework.web.client.RestTemplate;  
  
public RestTemplate createRestTemplateWithTrustingHttpClient() throws NoSuchAlgorithmException, KeyManagementException {  
    HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory();  
    factory.setHttpClient(createTrustingHttpClient());  
  
    return new RestTemplate(factory);  
}

　　3.使用RestTemplate进行请求：

public void makeRequest() throws NoSuchAlgorithmException, KeyManagementException {  
    RestTemplate restTemplate = createRestTemplateWithTrustingHttpClient();  
  
    String url = "https://example.com/api/endpoint";  
    RequestEntity<?> requestEntity = RequestEntity.get(URI.create(url)).build();  
    ResponseEntity<String> responseEntity = restTemplate.exchange(requestEntity, String.class);  
  
    // 处理响应...  
}　　

注意：

• 忽略SSL证书验证会降低你的应用的安全性，因为它容易受到中间人攻击。在生产环境中，你应该始终验证SSL证书。

• 如果确实需要忽略证书验证，确保完全了解相关的安全风险，并在完成后尽快恢复正常的证书验证。

3.自定义加载证书

　　在Java中使用RestTemplate进行HTTPS请求时，如果需要加载特定的HTTPS证书，通常需要使用一个自定义的HttpClient，并配置SSL上下文以加载你的证书。以下是一个使用Apache HttpClient和Spring RestTemplate加载特定HTTPS证书的示例：

1. 创建自定义的HttpClient

　　需要创建一个自定义的HttpClient，并配置SSL上下文以加载你的证书。

import org.apache.http.conn.ssl.SSLConnectionSocketFactory;  
import org.apache.http.impl.client.CloseableHttpClient;  
import org.apache.http.impl.client.HttpClients;  
import org.apache.http.ssl.SSLContexts;  
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;  
import org.springframework.web.client.RestTemplate;  
  
import javax.net.ssl.KeyManagerFactory;  
import javax.net.ssl.SSLContext;  
import javax.net.ssl.TrustManagerFactory;  
import java.io.FileInputStream;  
import java.io.IOException;  
import java.io.InputStream;  
import java.security.KeyStore;  
import java.security.KeyStoreException;  
import java.security.NoSuchAlgorithmException;  
import java.security.cert.CertificateException;  
  
public class CustomRestTemplate {  
  
    public static RestTemplate createRestTemplateWithCustomSSL() throws NoSuchAlgorithmException, KeyStoreException, CertificateException, IOException {  
        // 加载你的证书和私钥  
        KeyStore keyStore = KeyStore.getInstance("PKCS12");  
        try (InputStream certStream = new FileInputStream("path/to/your/cert.p12")) {  
            keyStore.load(certStream, "password".toCharArray()); // 替换为你的证书密码  
        }  
  
        KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());  
        keyManagerFactory.init(keyStore, "password".toCharArray()); // 替换为你的证书密码  
  
        TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());  
        trustManagerFactory.init(keyStore);  
  
        SSLContext sslContext = SSLContexts.custom()  
                .loadKeyMaterial(keyManagerFactory, "password".toCharArray()) // 替换为你的证书密码  
                .loadTrustMaterial(trustManagerFactory)  
                .build();  
  
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, SSLConnectionSocketFactory.NO_HOSTNAME_VERIFIER);  
  
        CloseableHttpClient httpClient = HttpClients.custom()  
                .setSSLSocketFactory(sslsf)  
                .build();  
  
        HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(httpClient);  
        return new RestTemplate(requestFactory);  
    }  
}

　　在上面的代码中，你需要替换path/to/your/cert.p12为你的证书文件路径，以及替换password为你的证书密码。

　　2.使用自定义的RestTemplate

　　现在你可以使用上面创建的RestTemplate实例进行HTTPS请求了。

public class MyService {  
  
    private final RestTemplate restTemplate;  
  
    public MyService() throws NoSuchAlgorithmException, KeyStoreException, CertificateException, IOException {  
        this.restTemplate = CustomRestTemplate.createRestTemplateWithCustomSSL();  
    }  
  
    public String makeHttpsRequest(String url) {  
        return restTemplate.getForObject(url, String.class);  
    }  
}