如何从邮递员以JSON格式发送POST请求

Question

我正在以邮递方式将Json格式的POST请求发送到以eclipse开发的API，但是却收到HTTP Status 500 – Internal Server Error。抛出的异常消息是：javax.servlet.ServletException：javax.ws.rs.ProcessingException：从实体流反序列化对象时出错。 我的pom.xml是：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>jerseydemo</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>jerseydemo</name>

    <build>
        <finalName>jerseydemo</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <inherited>true</inherited>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.glassfish.jersey</groupId>
                <artifactId>jersey-bom</artifactId>
                <version>${jersey.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet-core</artifactId>
            <!-- use the following artifactId if you don't need servlet 2.x compatibility -->
            <!-- artifactId>jersey-container-servlet</artifactId -->
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.inject</groupId>
            <artifactId>jersey-hk2</artifactId>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-binding</artifactId>
        </dependency>
    </dependencies>
    <properties>
        <jersey.version>2.31</jersey.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
</project>

我正在使用第二个功能（createcity）创建新数据：

package com.example.jerseydemo;
import java.util.List;

import javax.ws.rs.*;
import javax.ws.rs.core.MediaType;


@Path("cities")
public class CityResource {
    CityRepository cities = new CityRepository();
    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public List<City> getCity() {
        
        return cities.getAllCity();
    }
    @POST
    @Path("addcity")
    @Consumes(MediaType.APPLICATION_JSON)
    public City createcity(City city) {
        cities.create(city);
        return city;
    }
    
}

我用于存储数据的CityRepository函数是：

package com.example.jerseydemo;

import java.util.*;

public class CityRepository {
    List<City> cities;
    
    public CityRepository() {
        cities = new ArrayList<>();
        City city1 = new City(101, "Delhi");
        City city2 = new City(102, "Bombay");
        City city3 = new City(103, "Patna");
        cities.addAll(Arrays.asList(city1,city2,city3));
    }
    public List<City> getAllCity(){
        return cities;
    }
    public void create(City city) {
        // TODO Auto-generated method stub
        cities.add(city);
    }
    
}

我的GET请求功能运行正常。我是API开发的新手，所以现在很难找出错误并加以解决。请帮忙。