java 如何调用nexus的api接口

Java可以使用HTTP客户端库，如Apache HttpComponents或OkHttp来调用Nexus API接口。

以下是一个简单的例子，使用Apache HttpComponents库来获取Nexus中所有的artifact：

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import java.io.IOException;

public class NexusApiClient {
    public static void main(String[] args) throws IOException {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpGet httpGet = new HttpGet("http://nexus.example.com/service/rest/v1/search/assets?repository=maven-central");

        CloseableHttpResponse response = httpClient.execute(httpGet);
        String responseBody = EntityUtils.toString(response.getEntity());

        System.out.println(responseBody);

        response.close();
        httpClient.close();
    }
}

在上面的代码中，我们使用了Apache HttpComponents库来创建一个HTTP客户端，发送一个GET请求到Nexus的API接口，获取所有在maven-central仓库中的artifact。然后我们通过EntityUtils将响应实体转化为字符串并打印输出。

请注意，上面的代码仅供参考，实际的API调用应该包括错误处理和认证等安全措施。