Jenkins Java开发：获取触发构建的用户名

Hey there! To grab the username that started a Jenkins build from that specific page, you’ve got two reliable approaches—let’s break them down:

方法1：使用Jenkins REST API（推荐） #

Jenkins provides a built-in REST API that’s way more stable than scraping HTML, since page layouts can change unexpectedly. The build details endpoint returns all the info you need in JSON format.

步骤&代码示例 #

1. 首先，你的Java项目需要依赖JSON解析库，比如Jackson（或者Gson，whichever you prefer）。
2. 用Java的HttpClient（Java 11+自带）或者第三方库如OkHttp来发送请求到Jenkins API endpoint: http://[JENKINS_NAME]/job/[JOB_NAME]/[BUILD_NUMBER]/api/json
3. 解析返回的JSON，提取actions.causes.userName字段（这就是启动构建的用户名）。

Here’s a quick code snippet using Java 11 HttpClient and Jackson:

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class JenkinsBuildUserFetcher {
    public static void main(String[] args) throws Exception {
        // Replace these placeholders with your actual Jenkins details
        String jenkinsUrl = "http://[JENKINS_NAME]/job/[JOB_NAME]/[BUILD_NUMBER]/api/json";
        String username = "your-jenkins-username"; // If Jenkins requires auth
        String apiToken = "your-jenkins-api-token"; // Better than using password

        // Create HTTP client with basic auth if needed
        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create(jenkinsUrl))
                .header("Authorization", "Basic " + java.util.Base64.getEncoder().encodeToString((username + ":" + apiToken).getBytes()))
                .build();

        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

        // Parse JSON to get the username
        ObjectMapper mapper = new ObjectMapper();
        JsonNode rootNode = mapper.readTree(response.body());
        JsonNode causesNode = rootNode.path("actions").get(0).path("causes").get(0);
        String startedByUser = causesNode.path("userName").asText();

        System.out.println("Build started by: " + startedByUser);
    }
}

注意: 如果你的Jenkins实例不需要认证，可以去掉Authorization header那一行。

方法2：HTML页面解析（不推荐，应急用） #

If for some reason you can’t use the API, you can scrape the HTML page directly. This is fragile though—if Jenkins updates its UI layout, the code might break.

步骤&代码示例 #

Use a HTML parsing library like Jsoup to fetch the page and extract the username from the "Started by user [USER_NAME]" text:

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

public class JenkinsHtmlScraper {
    public static void main(String[] args) throws Exception {
        String jenkinsBuildUrl = "http://[JENKINS_NAME]/job/[JOB_NAME]/[BUILD_NUMBER]/";
        String username = "your-jenkins-username";
        String apiToken = "your-jenkins-api-token";

        // Fetch the page with auth if needed
        Document doc = Jsoup.connect(jenkinsBuildUrl)
                .userAgent("Mozilla/5.0")
                .auth(username, apiToken)
                .get();

        // Find the element containing the "Started by user" text
        String startedByText = doc.select("div.build-caption span").first().text();
        // Extract the username from the text
        String userName = startedByText.replace("Started by user ", "");

        System.out.println("Build started by: " + userName);
    }
}

提示: You’ll need to add Jsoup dependency to your project (e.g., Maven/Gradle) to use this code.

关键注意事项 #

• Permissions: Make sure the user account you’re using has permission to view the build details in Jenkins.
• API Tokens: Always use Jenkins API Tokens instead of plain passwords for authentication—you can generate them in your Jenkins user profile.
• Error Handling: The examples above skip error handling for brevity; in production code, add checks for HTTP errors, missing JSON fields, or HTML element changes.

内容的提问来源于stack exchange，提问作者George Cimpoies