Digest认证的接口工具类怎么写

Digest认证是一种HTTP基本认证的扩展形式，通常用于保护RESTful API。在编写Digest认证的接口工具类时，你需要考虑以下几个步骤：

1. **导入依赖**:
首先需要导入相关的库，如`java.net.HttpURLConnection`、`java.security.MessageDigest`等。

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.MessageDigest;

2. **创建请求头**:
创建包含Authorization字段的请求头，其中包含了计算出的摘要信息。这通常涉及到用户的用户名和密码以及特定的算法（如MD5或SHA-1）。

public static String createDigestAuthHeader(String username, String password, String algorithm) {
    try {
        MessageDigest digest = MessageDigest.getInstance(algorithm);
        byte[] credentials = (username + ":" + password).getBytes("UTF-8");
        byte[] digestBytes = digest.digest(credentials);
        StringBuilder hex = new StringBuilder();
        for (byte b : digestBytes) {
            hex.append(String.format("%02x", b & 0xff));
        }
        return "Basic " + Base64.getEncoder().encodeToString(hex.toString().getBytes());
    } catch (Exception e) {
        throw new RuntimeException("Failed to generate Digest authentication header", e);
    }
}

3. **发送请求并处理响应**:
使用`HttpURLConnection`发送GET或POST请求，并设置正确的请求头。

public HttpURLConnection makeAuthenticatedRequest(URL url, String username, String password, String algorithm) throws Exception {
    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    conn.setRequestMethod("GET"); // 替换成实际需求的请求方法
    conn.setRequestProperty("Authorization", createDigestAuthHeader(username, password, algorithm));
    conn.setDoOutput(true); // 如果有需要，可以设置输出流
    int responseCode = conn.getResponseCode();
    if (responseCode != HttpURLConnection.HTTP_OK) {
        throw new RuntimeException("Authentication failed: " + responseCode);
    }
    
    BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    // 读取并处理服务器返回的内容
    String line;
    StringBuilder content = new StringBuilder();
    while ((line = reader.readLine()) != null) {
        content.append(line);
    }
    reader.close();
    return conn;
}