尝试使用Spring Boot REST从POST读取JSON字符串

Question 1

我正在使用最新版本的Spring Boot通过Restful Web Service读取示例JSON ...

这是我的pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"       
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
         http://maven.apache.org/maven-v4_0_0.xsd"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <modelVersion>4.0.0</modelVersion>

    <groupId>org.springframework</groupId>
    <artifactId>myservice</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.2.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.7</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-rest-webmvc</artifactId>
        </dependency>
        <dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
        <repository>
            <id>org.jboss.repository.releases</id>
            <name>JBoss Maven Release Repository</name>
            <url>https://repository.jboss.org/nexus/content/repositories/releases</url>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>

</project>

这是我的网络服务代码：

import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/myservice")
public class BaseService {  

    @RequestMapping(value="/process", method = RequestMethod.POST)
    public void process(@RequestBody String payload) throws Exception {
        System.out.println(payload);
    }
}

当我使用以下命令调用它时：

curl -H "Accept: application/json" -H "Content-type: application/json" 
-X POST -d '{"name":"value"}' http://localhost:8080/myservice/process

我收到此错误消息：

{"timestamp":1427515733546,"status":400,
 "error":"Bad Request",

"exception":
"org.springframework.http.converter.HttpMessageNotReadableException","
 message":
 "Could not read JSON: Can not deserialize instance of java.lang.String
  out of START_OBJECT token\n at 

 [Source: java.io.PushbackInputStream@8252f; line: 1, column: 1]; 
  nested    exception is com.fasterxml.jackson.databind.JsonMappingException:
  Can not deserialize instance of java.lang.String out of START_OBJECT token\n    
  at [Source: java.io.PushbackInputStream@8252f; line: 1, column: 1]",
  "path":"/myservice/process"

我唯一想做的就是传递一些有效的JSON（作为通过curl的字符串），并查看String有效负载是否以{“ name”：“ value”}的形式进入处理方法

我可能做错了什么？

感谢您抽出时间来阅读...

Question 2

我认为使用JSON的最简单/便捷的方法是使用类似于JSON的Java类：https : //stackoverflow.com/a/6019761

但是，如果您不能使用Java类，则可以使用这两种解决方案之一。

解决方案1：您可以Map<String, Object>从控制器接收到它：

@RequestMapping(
    value = "/process", 
    method = RequestMethod.POST)
public void process(@RequestBody Map<String, Object> payload) 
    throws Exception {

  System.out.println(payload);

}

使用您的请求：

curl -H "Accept: application/json" -H "Content-type: application/json" \
-X POST -d '{"name":"value"}' http://localhost:8080/myservice/process

解决方案2：否则，您可以通过以下方式获取POST负载String：

@RequestMapping(
    value = "/process", 
    method = RequestMethod.POST,
    consumes = "text/plain")
public void process(@RequestBody String payload) throws Exception {

  System.out.println(payload);

}

然后根据需要解析该字符串。请注意，必须consumes = "text/plain"在控制器上指定。在这种情况下，您必须使用以下命令更改您的请求Content-type: text/plain：

curl -H "Accept: application/json" -H "Content-type: text/plain" -X POST \
-d '{"name":"value"}' http://localhost:8080/myservice/process

Question 3

如果要传递一个JSON数组，则可以添加到Andrea的解决方案中

[
    {"name":"value"},
    {"name":"value2"}
]

然后，您将需要像这样设置Spring Boot Controller：

@RequestMapping(
    value = "/process", 
    method = RequestMethod.POST)
public void process(@RequestBody Map<String, Object>[] payload) 
    throws Exception {

    System.out.println(payload);

}

Question 4

要在Spring-Boot中接收任意的Json，只需使用Jackson的即可JsonNode。相应的转换器会自动配置。

    @PostMapping(value="/process")
    public void process(@RequestBody com.fasterxml.jackson.databind.JsonNode payload) {
        System.out.println(payload);
    }

Question 5

为了进一步处理地图阵列，以下内容可能会有所帮助：

@RequestMapping(value = "/process", method = RequestMethod.POST, headers = "Accept=application/json")
public void setLead(@RequestBody Collection<? extends Map<String, Object>> payload) throws Exception {

  List<Map<String,Object>> maps = new ArrayList<Map<String,Object>>();
  maps.addAll(payload);

}

Question 6

从请求正文解析JSON时会出现问题，对于无效的JSON而言尤为常见。如果您在Windows上使用curl，请尝试转义json -d "{"name":"value"}"，甚至转义-d "{"""name""":"value"""}"

另一方面，您可以省略content-type标头，在这种情况下，发送wheewer的情况将转换为您的String参数