Neo4j - 服务器返回 HTTP 响应代码：500 用于 URL：http://localhost:7474/db/data/cypher

Question

我在使用 HTTPConnection 运行密码时遇到异常。

服务器返回 HTTP 响应代码：500 对应 URL：http://localhost:7474/db/data/cypher

public class HTTPConnectionTest {
    public static void main(String[] args) throws Exception {
        try {
                System.out.println("Testing HTTPConnection");
                StringBuffer responseString = new StringBuffer();
                String url = "http://localhost:7474/db/data/cypher";

                //String query = "match (user:USER{id:\'Sree\'}) return user ";
                String query = "match (user:USER{id:\"Sree\"}) return user ";
                URL neo4jUrl = new URL(url);
                HttpURLConnection httpConn = (HttpURLConnection) neo4jUrl
                        .openConnection();
                httpConn.setRequestMethod("POST");
                httpConn.setDoOutput(true);
                httpConn.setDoInput(true);
                httpConn.setRequestProperty("Content-Type", "application/json");
                String urlParameters = "{\"query\":\"" + query + "\"}";
                httpConn.setRequestProperty("Accept",
                        "application/json; charset=UTF-8");

                DataOutputStream wr = new DataOutputStream(
                        httpConn.getOutputStream());
                wr.writeBytes(urlParameters);
                wr.flush();
                wr.close();

                BufferedReader in = new BufferedReader(new InputStreamReader(
                        httpConn.getInputStream()));
                String inputLine;

                while ((inputLine = in.readLine()) != null) {
                    responseString.append(inputLine);
                }
                System.out.println("Out put " + responseString);
                in.close();
            } catch (Exception e) {
                System.out.println("Exception" + e.getMessage());
            }
    }
}

如果我用单引号在密码中传递值，它正在工作并获取输出对象。

字符串查询 = "匹配 (user:USER{id:\'Sree\'}) 返回用户 ";

有什么建议吗？提前谢谢！

Answer 1

这在我看来很愚蠢。

代码中的一个小改动。将参数转换为 JSONObject 字符串

JSONObject jsonObject = new JSONObject();
jsonObject.put("query", query);
String urlParameters = jsonObject.toString();

而不是

String urlParameters = "{\"query\":\"" + query + "\"}";