我正在使用Sping Boot 和Web依赖项创建一个简单的rest控制器。我尝试将JSON主体反序列化为只有3个字段的测试POJO,但当我尝试发出POST请求时,服务器响应500错误,我在控制台中得到的错误是:
.w.s.m.s.DefaultHandlerExceptionResolver : Failed to write HTTP message: org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type: class java.util.LinkedHashMap
我写的所有代码如下:
EmailApplication.java:
package com.test.email.app;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
@SpringBootApplication
@ComponentScan(basePackages = { "com.test.email" })
public class EmailApplication {
public static void main(String[] args) {
SpringApplication.run(EmailApplication.class, args);
}
@Bean
public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
return args -> {
System.out.println("----- You're up and running with test-email-app! -----");
};
}
}
EmailController.java:
package com.test.email.controller;
import com.test.email.entity.TestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.RequestMapping;
import java.net.URI;
@RestController
public class EmailController {
@RequestMapping(value = "/", method = RequestMethod.GET)
public String index() {
TestEntity entity = new TestEntity();
return "test-email-app index";
}
@RequestMapping(value = "/poster", method = RequestMethod.POST)
public ResponseEntity<String> poster(@RequestBody TestEntity testEntity) {
URI location = URI.create("/poster");
return ResponseEntity.created(location).body(testEntity.getUrl());
}
}
TestEntity.java
package com.test.email.entity;
/**
* An entity for serialization/deserialization testing
*/
public class TestEntity {
public String url;
public int count;
public double height;
public TestEntity() {}
public TestEntity(String url, int count, double height) {
this.url = url;
this.count = count;
this.height = height;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public int getCount() {
return count;
}
public void setCount(int count) {
this.count = count;
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
}
我用Postman只使用头部Content-Type: application/json
和主体来发出POST请求:
{ "url": "http://google.com", "count": 3, "height": 2.4 }
我不知道为什么Spring不能从LinkedHashMap转换到我的POJO。任何帮助将不胜感激。
编辑:
我的pom.xml如下:
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.test.email</groupId>
<artifactId>test-email-app</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>test-email-app</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<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>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3条答案
按热度按时间mzillmmw1#
在分析您的问题后,我发现了一些可能出现此问题的情况。以下给出:
1.内部类:
如果您的类
TestEntity
是您端点的Inner class。只要将TestEntity
从Inner class转移到一个单独的类中并运行代码,它就可以工作。1.支持内部类:
如果你想支持内部类一个RequestBody然后使
TestEntity
类为static,这将解决你的问题。1.Spring依赖配置:
如果仍然没有解决您的问题,请检查您对
pom.xml
的依赖性。可能你没有以正确的方式添加依赖性。您可以查看this answer。也可以在pom.xml
文件中显式添加jackson
。依赖项为:
相关链接:Spring @Requestbody not mapping to inner class
wbgh16ku2#
尝试指定您的方法使用JSON。更改注解:
@RequestMapping(value = "/poster", method = RequestMethod.POST)
到
这里的主要部分是指定您接受JSON输入。不确定返回的类型,但可以指定适当的类型或删除“produces”部分。主要的部分是指定你的输入是什么
ajsxfq5m3#
理想情况下,这段代码应该可以工作,但给予尝试在pom.xml中添加以下依赖项