RDF4J REST API更新返回500，'事务处理错误：java.util.concurrent.ExecutionException：java.lang.NullPointerException'

Question

我使用python来查询RDF4J的REST API，但我似乎无法得到它如文档中描述的工作（http://docs.rdf4j.org/rest-api/#_the_rdf4j_server_rest_api）

我做这工作正常，但当我尝试做一个INSERT语句，我得到以下错误select语句：

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

做一个POST请求我生成一个交易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 

我真的很感激一些这方面的帮助。

Answer 1

您可以找到发表@Jeen Broekstra在评论部分答案：

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