RDF4J REST API update returning 500, 'Transaction handling error: java.util.concurrent.ExecutionException: java.lang.NullPointerException'

Question

我正在使用 python 查询 RDF4J 的 REST API，但我似乎无法按照文档中的描述使其工作 (http://docs.rdf4j.org/rest-api/#_the_rdf4j_server_rest_api)

我正在做一个 select 语句，它工作正常，但是当我尝试做一个插入语句时，我收到以下错误：

"500, 'Transaction handling error: java.util.concurrent.ExecutionException: java.lang.NullPointerException'"

为了执行 POST 请求，我生成了一个事务 ID，然后执行实际的 POST 请求：

# Generate tranzaction ID
transaction_id = requests.post('http://localhost:8080/rdf4j-server/repositories/ProiectICVG/transactions')enter code here
transaction_id = transaction_id.headers['Location']
transaction_id = string.split(transaction_id, '/')
transaction_id = transaction_id[-1]

#Make the post request
return_data = requests.post('http://localhost:8080/rdf4j-server/repositories/ProiectICVG/transactions/'+transaction_id+'?action=UPDATE',
                         data={'Host': 'localhost',
                               'Content-Type': 'application/sparql-query',
                               'query': 'PREFIX : <http://proj.local#>\
                                        insert data {\
                                        graph :isIncidentGraph{\
                                        :INC005 :hasTtile "test".}'
                               })
print(return_data.status_code, return_data.content)

输出如下：

"C:\Python27\python.exe D:/xamp/cgi-bin/index.py
(500, 'Transaction handling error: java.util.concurrent.ExecutionException: java.lang.NullPointerException')

Process finished with exit code 0

我真的很感激在这方面的帮助。

Answer 1

您可以在@Jeen Broekstra 发表的评论部分找到答案：

You're doing a POST where the documentation says you should be using PUT: http://docs.rdf4j.org/rest-api/#_the_update_operation