支持SAML 2.0 HTTP Artifact Binding的IDP是什么？

支持SAML 2.0 HTTP Artifact Binding的IDP是指支持使用HTTP Artifact Binding作为SAML 2.0协议的一种绑定方式的身份提供者（Identity Provider）。下面是一个使用Java的代码示例，演示如何配置一个支持SAML 2.0 HTTP Artifact Binding的IDP。

import org.opensaml.saml2.core.Assertion;
import org.opensaml.saml2.core.Artifact;
import org.opensaml.saml2.core.ArtifactResolve;
import org.opensaml.saml2.core.ArtifactResponse;
import org.opensaml.saml2.core.Response;
import org.opensaml.saml2.core.Status;
import org.opensaml.saml2.core.StatusCode;
import org.opensaml.saml2.core.impl.ArtifactBuilder;
import org.opensaml.saml2.core.impl.ArtifactResolveBuilder;
import org.opensaml.saml2.core.impl.ArtifactResponseBuilder;
import org.opensaml.saml2.core.impl.ResponseBuilder;
import org.opensaml.xml.Configuration;
import org.opensaml.xml.XMLObject;
import org.opensaml.xml.io.Unmarshaller;
import org.opensaml.xml.io.UnmarshallerFactory;
import org.opensaml.xml.util.XMLHelper;
import org.w3c.dom.Element;

import javax.xml.namespace.QName;
import java.io.ByteArrayInputStream;
import java.nio.charset.StandardCharsets;

public class IDPExample {
    public static void main(String[] args) throws Exception {
        // 构建ArtifactResolve请求
        ArtifactResolve artifactResolve = buildArtifactResolve("artifactValue");

        // 发送ArtifactResolve请求到IDP
        String artifactResponseXml = sendArtifactResolve(artifactResolve);

        // 解析ArtifactResponse响应
        ArtifactResponse artifactResponse = parseArtifactResponse(artifactResponseXml);

        // 获取ArtifactResponse中的SAML响应
        Response samlResponse = artifactResponse.getMessage();

        // 处理SAML响应
        if (samlResponse.getStatus().getStatusCode().getValue().equals(StatusCode.SUCCESS_URI)) {
            // 提取Assertion
            Assertion assertion = samlResponse.getAssertions().get(0);
            // 处理Assertion数据
            System.out.println("Received Assertion: " + assertion);
        } else {
            // 处理错误状态
            Status status = samlResponse.getStatus();
            System.out.println("Error: " + status.getStatusCode().getValue());
        }
    }

    private static ArtifactResolve buildArtifactResolve(String artifactValue) {
        ArtifactResolveBuilder artifactResolveBuilder = (ArtifactResolveBuilder) Configuration.getBuilderFactory()
                .getBuilder(ArtifactResolve.DEFAULT_ELEMENT_NAME);
        ArtifactResolve artifactResolve = artifactResolveBuilder.buildObject();
        artifactResolve.setArtifact(buildArtifact(artifactValue));
        return artifactResolve;
    }

    private static Artifact buildArtifact(String artifactValue) {
        ArtifactBuilder artifactBuilder = (ArtifactBuilder) Configuration.getBuilderFactory()
                .getBuilder(Artifact.DEFAULT_ELEMENT_NAME);
        Artifact artifact = artifactBuilder.buildObject();
        artifact.setArtifact(artifactValue);
        return artifact;
    }

    private static String sendArtifactResolve(ArtifactResolve artifactResolve) {
        // 在此处发送ArtifactResolve请求到IDP，并将响应作为字符串返回
        // 示例中使用硬编码的响应字符串作为示例
        return "ArtifactResponse XML";
    }

    private static ArtifactResponse parseArtifactResponse(String artifactResponseXml) throws Exception {
        // 将ArtifactResponse XML字符串转换为DOM元素
        Element artifactResponseElement = XMLHelper.buildElement(artifactResponseXml);

        // 创建ArtifactResponse的Unmarshaller
        UnmarshallerFactory unmarshallerFactory = Configuration.getUnmarshallerFactory();
        Unmarshaller unmarshaller = unmarshallerFactory.getUnmarshaller(artifactResponseElement);
        if (unmarshaller == null) {
            throw new Exception("No unmarshaller found for artifactResponseElement");
        }

        // 使用Unmarshaller将DOM元素解析为ArtifactResponse对象
        XMLObject xmlObject = unmarshaller.unmarshall(artifactResponseElement);
        if (xmlObject == null || !(xmlObject instanceof ArtifactResponse)) {
            throw new Exception("Failed to unmarshall ArtifactResponse");
        }

        return (ArtifactResponse) xmlObject;
    }
}

请注意，示例中的代码仅展示了一个简单的示例，实际使用时需要根据具体的IDP和SP配置进行相应的定制。