尝试在 Java 中使用 HttpClient 发送 HTTP Post GraphQL 查询时出现 HTTP 400
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【中文标题】尝试在 Java 中使用 HttpClient 发送 HTTP Post GraphQL 查询时出现 HTTP 400【英文标题】：HTTP 400 When Trying to Send HTTP Post GraphQL Query using HttpClient in Java 【发布时间】：2018-10-18 07:07:00 【问题描述】：对外部 GraphQL 服务器进行后查询，该服务器在 Postman Pro 设置中作为预请求脚本工作。
我正在尝试使用 HttpClient 访问外部 GraphQL 服务器。
Maven 依赖 pom.xml：
<!-- Apache Commons -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.6</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.2.5</version>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.2.4</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient-cache</artifactId>
<version>4.2.5</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.2.5</version>
</dependency>
<!-- Google Code -->
<dependency>
<groupId>com.googlecode.json-simple</groupId>
<artifactId>json-simple</artifactId>
<version>1.1.1</version>
</dependency>
将预请求脚本硬编码如下：
GetDataAsRequest.java
public class GetDataAsRequest
private static final String GET_DATA_REQUEST_TEMPLATE =
"query "
+ " viewer "
+ " data(id: \"10045701-2017-41a4-33f4-bf8481cf01dc\") " +
" id"
+ " createdDate"
+ " lastModifiedDate"
+ " abbreviation"
+ " cityStateRegion"
+ " "
+ " "
+ "";
public static String generateQuery()
return String.format(GET_DATA_REQUEST_TEMPLATE);
我的控制器：
public class MyController
private static final String EXTERNAL_API_URL = "https://sample-api.com"
public static void main (String args [])
// Generate Access Token
String accessToken = OAuth2Client.generateAccessToken();
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost postRequest = new HttpPost(EXTERNAL_API_URL);
StringEntity postBody = new StringEntity(GetDataAsRequest.generateQuery());
postBody.setContentType("application/json");
postRequest.addHeader("Authorization", "Bearer " + accessToken);
postRequest.setEntity(postBody);
HttpResponse response = httpClient.execute(postRequest);
if (response.getStatusLine().getStatusCode() != 201)
throw new RuntimeException("Failed : HTTP error code : " + response.getStatusLine().getStatusCode());
BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));
String output;
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null)
System.out.println(output);
httpClient.getConnectionManager().shutdown();
catch (MalformedURLException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();
虽然当我将其从标准输入（控制台）复制到 Postman 调用时，相同的 OAuthToken 和 HTTP 发布查询有效，但在 Java 程序中尝试使用 HttpClient 模拟相同的调用时，我不断收到 HTTP 400：
03:25:30.690 [main] DEBUG org.apache.http.impl.conn.BasicClientConnectionManager - Get connection for route s->https://https://sample-api.com
03:25:30.751 [main] DEBUG org.apache.http.impl.conn.DefaultClientConnectionOperator - Connecting to https://sample-api.com:443
03:25:30.943 [main] DEBUG org.apache.http.client.protocol.RequestAddCookies - CookieSpec selected: best-match
03:25:30.950 [main] DEBUG org.apache.http.client.protocol.RequestAuthCache - Auth cache not set in the context
03:25:30.950 [main] DEBUG org.apache.http.client.protocol.RequestTargetAuthentication - Target auth state: UNCHALLENGED
03:25:30.951 [main] DEBUG org.apache.http.client.protocol.RequestProxyAuthentication - Proxy auth state: UNCHALLENGED
03:25:30.951 [main] DEBUG org.apache.http.impl.client.DefaultHttpClient - Attempt 1 to execute request
03:25:30.951 [main] DEBUG org.apache.http.impl.conn.DefaultClientConnection - Sending request: POST /v1/oauth/token HTTP/1.1
03:25:30.951 [main] DEBUG org.apache.http.wire - >> "POST /v1/oauth/token HTTP/1.1[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.wire - >> "Content-Length: 119[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.wire - >> "Content-Type: application/x-www-form-urlencoded; charset=UTF-8[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.wire - >> "Host: https://sample-api.com[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.wire - >> "Connection: Keep-Alive[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.wire - >> "User-Agent: Apache-HttpClient/4.2.5 (java 1.5)[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.wire - >> "[\r][\n]"
03:25:30.952 [main] DEBUG org.apache.http.headers - >> POST /v1/oauth/token HTTP/1.1
03:25:30.952 [main] DEBUG org.apache.http.headers - >> Content-Length: 119
03:25:30.952 [main] DEBUG org.apache.http.headers - >> Content-Type: application/x-www-form-urlencoded; charset=UTF-8
03:25:30.952 [main] DEBUG org.apache.http.headers - >> Host: https://sample-api.com
03:25:30.952 [main] DEBUG org.apache.http.headers - >> Connection: Keep-Alive
03:25:30.953 [main] DEBUG org.apache.http.headers - >> User-Agent: Apache-HttpClient/4.2.5 (java 1.5)
03:25:30.953 [main] DEBUG org.apache.http.wire - >> "grant_type=client_credentials&client_id=fghuXeULFBdW4B1dmRY0MhROMRQnlumk&client_secret=MM2banXEq2R1GhRvIQ2d2AKRx0SORvb4"
03:25:31.132 [main] DEBUG org.apache.http.wire - << "HTTP/1.1 200 OK[\r][\n]"
03:25:31.134 [main] DEBUG org.apache.http.wire - << "X-Application-Context: application:prod[\r][\n]"
03:25:31.134 [main] DEBUG org.apache.http.wire - << "Content-Type: application/json[\r][\n]"
03:25:31.134 [main] DEBUG org.apache.http.wire - << "Cache-Control: no-store[\r][\n]"
03:25:31.134 [main] DEBUG org.apache.http.wire - << "Pragma: no-cache[\r][\n]"
03:25:31.134 [main] DEBUG org.apache.http.wire - << "Accept-Ranges: bytes[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "X-Cache-Hits: 0[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "X-Timer: S1525774921.421988,VS0,VE41[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "Date: Tue, 08 May 2018 10:22:01 GMT[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "Content-Length: 325[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "Connection: keep-alive[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "X-Sample-APP: sso[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "Access-Control-Allow-Headers: Authorization,Content-Type[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "Access-Control-Allow-Methods: PUT,POST,OPTIONS,GET,PATCH,DELETE[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "Access-Control-Allow-Origin: *[\r][\n]"
03:25:31.135 [main] DEBUG org.apache.http.wire - << "[\r][\n]"
03:25:31.136 [main] DEBUG org.apache.http.impl.conn.DefaultClientConnection - Receiving response: HTTP/1.1 200 OK
03:25:31.136 [main] DEBUG org.apache.http.headers - << HTTP/1.1 200 OK
03:25:31.136 [main] DEBUG org.apache.http.headers - << X-Application-Context: application:prod
03:25:31.136 [main] DEBUG org.apache.http.headers - << Content-Type: application/json
03:25:31.136 [main] DEBUG org.apache.http.headers - << Cache-Control: no-store
03:25:31.136 [main] DEBUG org.apache.http.headers - << Pragma: no-cache
03:25:31.138 [main] DEBUG org.apache.http.headers - << Accept-Ranges: bytes
03:25:31.138 [main] DEBUG org.apache.http.headers - << X-Served-By: cache-sample-las9320
03:25:31.138 [main] DEBUG org.apache.http.headers - << X-Cache-Hits: 0
03:25:31.138 [main] DEBUG org.apache.http.headers - << X-Timer: S1525774921.421988,VS0,VE41
03:25:31.138 [main] DEBUG org.apache.http.headers - << Date: Tue, 08 May 2018 10:22:01 GMT
03:25:31.138 [main] DEBUG org.apache.http.headers - << Content-Length: 325
03:25:31.138 [main] DEBUG org.apache.http.headers - << Connection: keep-alive
03:25:31.138 [main] DEBUG org.apache.http.headers - << X-Sample-APP: sso
03:25:31.138 [main] DEBUG org.apache.http.headers - << Access-Control-Allow-Headers: Authorization,Content-Type
03:25:31.138 [main] DEBUG org.apache.http.headers - << Access-Control-Allow-Methods: PUT,POST,OPTIONS,GET,PATCH,DELETE
03:25:31.138 [main] DEBUG org.apache.http.headers - << Access-Control-Allow-Origin: *
03:25:31.141 [main] DEBUG org.apache.http.impl.client.DefaultHttpClient - Connection can be kept alive indefinitely
03:25:31.147 [main] DEBUG org.apache.http.wire - << ""access_token":"fkMmGciOiJIUzI1NiJ9.eyJ1c2VybmFtZSI6bnVsbCwiZGV2aWNlSWQiOm51bGwsImNsaWVudElkIjoiaUxIdVhlVUxGQmRXNEIxZG1SWTBNaFJPTVJRbmxmZUsiLCJhZElkIjpudWxsLCJleHAiOjE1MjU3Nzg1MjEsImlhdCI6MTUyNTc3NDkyMX0.U3gacgf7a8hlwCuCn6yGXc0z6E5Zrwgii3B_77xFlyo","token_type":"Bearer","expires_in":3600,"refresh_token":null,"scope":null"
03:25:31.147 [main] DEBUG org.apache.http.impl.conn.BasicClientConnectionManager - Releasing connection org.apache.http.impl.conn.ManagedClientConnectionImpl@2ddc8ecb
03:25:31.147 [main] DEBUG org.apache.http.impl.conn.BasicClientConnectionManager - Connection can be kept alive indefinitely
Exception in thread "main" java.lang.RuntimeException: Failed : HTTP error code : 400
返回 HTTP 400 是否是因为我的请求正文在某些方面有误？
有没有更简单的方法通过 GraphQL 的 Java 库获取 JSON 响应：
<!-- GraphQL -->
<dependency>
<groupId>com.graphql-java</groupId>
<artifactId>graphql-java</artifactId>
<version>8.0</version>
</dependency>
<dependency>
<groupId>com.graphql-java</groupId>
<artifactId>graphql-java-tools</artifactId>
<version>5.0.0</version>
</dependency>
互联网上有很多例子展示了如何设置和外部的 GraphQL 服务器，我需要学习如何使用 GraphQL Java 库作为客户端库来解析并从外部服务器获取正确的 GraphQL 响应。 ..
这从 Postman Pro 和 curl 正确返回，但不使用 HttpClient。
我可能做错了什么？
【问题讨论】：
【参考方案1】：你控制服务器吗？如果是这样，为什么不在那里放置一个断点并检查失败的地方？如果您不控制服务器，我会说仔细检查您在此处发送的内容与使用 Postman 发送的内容之间的差异。
一件事立刻看起来很可疑。您发送的 POST 声称具有 JSON 正文，但您发送的字符串是原始 GraphQL 查询，根本不是 JSON。
我可以告诉您将请求正文转换为 GraphQL over HTTP Spec 定义的 JSON 对象，但在不知道您的服务器是否实际实现此规范的情况下，这只是猜测。
规范定义为 POST 请求的正确主体的是具有 3 个字段的 JSON 对象：query、operationName 和 variables。 query 字段应包含查询 string （因此首先对查询进行字符串化），operationName 包含在有多个时要执行的操作的名称（与您的情况无关），以及 @ 987654327@ 包含一个 JSON 对象，其中变量作为键值对（现在不相关）。
在您的情况下，正文应如下所示：
query: "
viewer
data(id: \"10045701-2017-41a4-33f4-bf8481cf01dc\")
id
createdDate
lastModifiedDate
abbreviation
cityStateRegion
"
要将这个字符串放入 Java 代码中，所有这些都需要额外的转义级别，但我希望您的 IDE 能够处理好这一点。还要注意换行符很重要。如果您因任何原因丢失它们，您必须在所选字段之间放置逗号，以使查询保持有效。
【讨论】：
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