Netflix 已开放其 Domain Graph Service（DGS）框架的源代码 ，该框架是为了方便整合 GraphQL 使用，用于简化 GraphQL 的实现。
GraphQL 主要是作用于数据接口，比如前端后端交互。无需定义或修改后台 Controller、Service 等业务代码即可实现灵活的数据变更，客户端可以自由获取服务端事先定义好的数据，提高了交互接口的灵活性
组件依赖
- graphql-dgs-spring-boot-starter
<pre class="custom" style="font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: 15px; position: relative; overflow: auto; line-height: 1.75; color: rgb(51, 51, 51); background: rgb(248, 248, 248); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;"><dependency> <groupId>com.netflix.graphql.dgs</groupId> <artifactId>graphql-dgs-spring-boot-starter</artifactId> <version>3.5.1</version> </dependency> 复制代码</pre>
- DGS 必须从 jcenter 下载,不然部分依赖无法下载。踩坑很久
<pre class="custom" style="font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: 15px; position: relative; overflow: auto; line-height: 1.75; color: rgb(51, 51, 51); background: rgb(248, 248, 248); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;"><profiles> <profile> <activation> <activeByDefault>true</activeByDefault> </activation> <repositories> <repository> <snapshots> <enabled>false</enabled> </snapshots> <id>central</id> <name>bintray</name> <url>https://jcenter.bintray.com</url> </repository> </repositories> <pluginRepositories> <pluginRepository> <snapshots> <enabled>false</enabled> </snapshots> <id>central</id> <name>bintray-plugins</name> <url>https://jcenter.bintray.com</url> </pluginRepository> </pluginRepositories> <id>bintray</id> </profile> </profiles> 复制代码</pre>
定义接口 schema
- /src/main/resources/schema/schema.graphqls
此文件定义了客户端请求入参格式和查询数据类型
<pre class="custom" style="font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: 15px; position: relative; overflow: auto; line-height: 1.75; color: rgb(51, 51, 51); background: rgb(248, 248, 248); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">`type Query {
shows(title: String ,releaseYear: Int): [Show]
}
type Show {
title: String
releaseYear: Int
}
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定义数据抽取规则
<pre class="custom" style="font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: 15px; position: relative; overflow: auto; line-height: 1.75; color: rgb(51, 51, 51); background: rgb(248, 248, 248); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">`@DgsComponent
public class ShowsDatafetcher {
@DgsData(parentType = "Query", field = "shows")
public List<Show> shows(@InputArgument("title") String title, @InputArgument("releaseYear") Integer releaseYear) {
if (title == null) {
return shows;
}
return shows.stream().filter(s -> s.getTitle().contains(title)).collect(Collectors.toList());
}
// 模拟 DB 查询
private final List<Show> shows = List.of(
new Show("java", 1995),
new Show("php", 1995),
new Show("python", 1990),
new Show("golang", 2009),
new Show("rust", 2015)
);
}
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UI 前端调试
- 条件查询
接口调用
<pre class="custom" style="font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: 15px; position: relative; overflow: auto; line-height: 1.75; color: rgb(51, 51, 51); background: rgb(248, 248, 248); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">curl --location --request POST 'http://localhost:8080/graphql' \ --header 'Content-Type: application/json' \ --data-raw '{"query":"{\n shows(title: \"java\", releaseYear: 1995) {\n title\n releaseYear\n }\n}\n","variables":null}' 复制代码</pre>
java 调用
<pre class="custom" style="font-family: Menlo, Monaco, Consolas, "Courier New", monospace; font-size: 15px; position: relative; overflow: auto; line-height: 1.75; color: rgb(51, 51, 51); background: rgb(248, 248, 248); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">`@SpringBootTest(classes = {DgsAutoConfiguration.class, ShowsDatafetcher.class})
class ShowsDatafetcherTests {
@Autowired
DgsQueryExecutor dgsQueryExecutor;
@Test
void shows() {
List<String> titles = dgsQueryExecutor.executeAndExtractJsonPath(
" { shows { title releaseYear }}",
"data.shows[*].title");
assertThat(titles).contains("java");
}
}
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本节源码
源码: https://github.com/lltx/dgs-demo
DGS 官网: https://netflix.github.io/dgs
>>> 源码 https://gitee.com/log4j/pig，欢迎署名转载 <<<
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