Jackson2HttpMessageConverter
用处
- SpringMVC中,controller中的方法返回java Bean对象,mvc将此对象转换成字符串
- 默认支持的mediaType: MediaType.APPLICATION_JSON, new MediaType("application", "*+json"),也就json请求
为什么改造
想让url以.html结尾的请求走json请求的逻辑
现状
当后端使用如下方法编码时,url以.html为后缀,最终会响应406状态页面
后端@RestController返回java对象
@RequestMapping(value = "/data", method = {RequestMethod.POST, RequestMethod.GET})
public ApiResult data(HttpServletRequest httpServletRequest, String type, String param, Model model) {
return new ApiResult(2);
}
目标
修改后/data.html返回
{ "code" : 2 }
修改方式
/**
* 自定义的jackson到httpmessage的转换器
* Created by cdliujian1 on 2018/1/27.
*/
public class JMappingJackson2HttpMessageConverter extends MappingJackson2HttpMessageConverter {
/**
* Construct a new {@link MappingJackson2HttpMessageConverter} using default configuration
* provided by {@link Jackson2ObjectMapperBuilder}.
*/
public JMappingJackson2HttpMessageConverter() {
this(Jackson2ObjectMapperBuilder.json().build());
}
/**
* Construct a new {@link MappingJackson2HttpMessageConverter} with a custom {@link ObjectMapper}.
* You can use {@link Jackson2ObjectMapperBuilder} to build it easily.
* @see Jackson2ObjectMapperBuilder#json()
*/
public JMappingJackson2HttpMessageConverter(ObjectMapper objectMapper) {
super(objectMapper);
List<MediaType> mediaTypes = getSupportedMediaTypes();
List<MediaType> newMediaTypes = new ArrayList<>();
newMediaTypes.add(MediaType.TEXT_HTML);
newMediaTypes.addAll(mediaTypes);
setSupportedMediaTypes(newMediaTypes);
}
}
构造函数中,调用setSupportedMediaTypes方法,将MediaType.TEXT_HTML添加到当前HttpMessageConverter支持媒体类型中
这样当.html后缀结尾的链接到后端时,可以进入到MappingJackson2HttpMessageConverter的处理流程
MvcConfiguration
@Configuration
//@EnableWebMvc
public class MvcConfiguration extends WebMvcConfigurerAdapter {
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder()
.indentOutput(true)
.dateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
converters.add(new JMappingJackson2HttpMessageConverter(builder.build()));
converters.add(new MappingJackson2XmlHttpMessageConverter(builder.xml().build()));
}
}