java - 服务器返回 HTTP 响应代码 : 400 for URL : HttpURLConnection Error

Question

我正在尝试在 java 中复制以下 unix cURL 命令:

curl -X POST http://api.nigelsmall.com/xml-cypher -d @test/files/abba.xml

编辑:

更具体地说，我正在尝试在 java 中复制以下 cURL 命令:

curl -X POST http://api.nigelsmall.com/xml-cypher -d "<?xml version='1.0' encoding='UTF-8' ?><group><member></member></group>"

到目前为止，我有以下代码:

String urlString = "http://api.nigelsmall.com/xml-cypher";
    try {
        URL url = new URL(urlString);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestProperty("Content-Type", "application/xml");
        conn.setDoOutput(true);
        conn.setRequestMethod("POST");
        String data = "<?xml version='1.0' encoding='UTF-8' ?><group><member></member></group>";
        OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
        out.write(data);
        out.flush();


        BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = rd.readLine()) != null) {
            System.out.println(line);
        }
        out.close();
        rd.close();
    } 


    catch (Exception e) {
        System.out.println(e);
        e.printStackTrace();
    }

但是 java.io.IOException:服务器返回 HTTP 响应代码:400 对于 URL:http://api.nigelsmall.com/xml-cypher发生。谁能找出问题所在吗？

我唯一能想到的是，我可能需要将 XML 放入文件中并将其作为请求发送。但我不知道该怎么做。有人能帮我解决这个问题吗？提前致谢。

Answer 1

这不是你的错。 Web 服务的文档缺少一个重要的细节:

如果发布 JSON，您可以这样做。发布 XML 时，您必须提供 XML，就像以 HTML 表单发布一样:application/x-www-form-urlencoded。

在 source code您可以看到的服务:

def _convert(method):
    a = request.accept_mimetypes.best_match(["application/json", "text/html"])
    if a == "application/json":
        xml = request.get_data().decode("utf-8")
    else:
        xml = request.form["xml"]   # <-- xml is a form field!!
    # ...    

我已经尝试过 DavidWebb这只是 HttpURLConnection 的一个小包装，它起作用了:

public void testNigelsmall() throws Exception {

    String payload = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n" +
            "<group id=\"abba\">\n" +
            "  <member id=\"agnetha\">\n" +
            "    <name>Agnetha Fältskog</name>\n" +
            "    <birth date=\"1950-04-05\" />\n" +
            "  </member>\n" +
            "  <member id=\"frida\">\n" +
            "    <name>Anni-Frid Lyngstad</name>\n" +
            "    <birth date=\"1945-11-15\" />\n" +
            "  </member>\n" +
            "  <song id=\"waterloo\" release_date=\"1974-03-04\">\n" +
            "    <name>Waterloo</name>\n" +
            "    <length min=\"2\" sec=\"42\" />\n" +
            "  </song>\n" +
            "</group>";

    Webb webb = Webb.create();
    Response<String> response = webb
            .post("http://api.nigelsmall.com/xml-cypher")
            .param("xml", payload)
            .asString();

    assertEquals(200, response.getStatusCode());
    assertNotNull(response.getBody());
    assertTrue(response.getBody().startsWith("CREATE"));
    assertTrue(response.getBody().contains("(abba)-[:member]->(frida)"));
}

输出:

CREATE
(abba),
(agnetha {name:"Agnetha F\u00e4ltskog",`birth date`:"1950-04-05"}),
(frida {name:"Anni-Frid Lyngstad",`birth date`:"1945-11-15"}),
(waterloo {`length sec`:42,`length min`:2,name:"Waterloo"}),
(abba)-[:member]->(agnetha),
(abba)-[:member]->(frida),
(abba)-[:song {release_date:"1974-03-04"}]->(waterloo)