自定义参数解析器

开发中，app端给服务端会传基础参数、其他参数，一般基础参数app端都会传给服务端，其他参数则是根据不同接口传不同参数。若以表单的形式提交的数据:

其中请求参数params就是上文所说的其他参数，而除了它都是基本参数，param的值是json字符串，对于这种请求方式用@RequestParam、@RequestBody都不能满足要求，用spring中自定义的参数解析器恰好可以解决这个问题。

首先定义映射参数的类

UserParam:

public class UserParam extends BaseParam{
    private UserInfoEntity params;//其他参数映射类

    public UserInfoEntity getParams() {
        return params;
    }

    public void setParams(UserInfoEntity params) {
        this.params = params;
    }

    public void setParamsFromJson(String json){
        UserInfoEntity userInfoEntity = null;
        try {
            userInfoEntity = JSONUtils.json2pojo(json,UserInfoEntity.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
        setParams(userInfoEntity);
    }
}

BaseParam(基础参数类):

public class BaseParam {
    public String token;
    public String channel;
    public String clientId;


    public String getToken() {
        return token;
    }

    public void setToken(String token) {
        this.token = token;
    }

    public String getChannel() {
        return channel;
    }

    public void setChannel(String channel) {
        this.channel = channel;
    }

    public String getClientId() {
        return clientId;
    }

    public void setClientId(String clientId) {
        this.clientId = clientId;
    }
}

Controller类方法

@RestController
public class HelloController {
    @Autowired
    UserInfoService userInfoService;
    @PostMapping(value = "/lios/boot/ok",produces = {"application/json;charset=utf-8"})
    public Object ok(UserParam param){
        return userInfoService.selectByMobile(param.getParams().getMobile());
    }
}

自定义参数解析器类

public class CustomArgumentResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter methodParameter) {
        Class paramObjClass = methodParameter.getParameterType();
        if(BaseParam.class.isAssignableFrom(paramObjClass)){
            return true; //参数为BaseParam.class类类型时,则执行resolveArgument方法
        }
        return false;
    }
    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {

        Class paramObjClass = parameter.getParameterType();//获取参数类类型

        Object paramObj = paramObjClass.newInstance();//根据class new 出对象

        Map param = webRequest.getParameterMap();//获取所有请求参数
        for (Map.Entry entry : param.entrySet()) {
            String[] val = entry.getValue();
            if (val != null && "params".equals(entry.getKey())) {
                Method method = paramObjClass.getMethod("setParamsFromJson", String.class);//获取到方法setParamsFromJson的对象
                method.invoke(paramObj, val[0]);//把params的值当作形参传入
            } else if (val != null && val.length == 1) { //基础类参数处理
                Field field =null;
                if(paramObjClass.getName().equals(BaseParam.class.getName())){
                    field=paramObjClass.getDeclaredField(entry.getKey());
                }else {
                    field= paramObjClass.getSuperclass().getDeclaredField(entry.getKey());
                }
                //把基础参数的值放入UserParam中
                if (field.getType().isAssignableFrom(String.class)) {
                    field.set(paramObj, val[0]);
                } else if (field.getType().isAssignableFrom(Integer.class)) {
                    field.set(paramObj, Integer.valueOf(val[0]));
                } else if (field.getType().isAssignableFrom(Long.class)) {
                    field.set(paramObj, Long.valueOf(val[0]));
                } 
            }
        }
        return paramObj;
    }
}

配置

• 一般项目配置

              <mvc:annotation-driven>
                <mvc:argument-resolvers>
                    <bean class="com.lios.api.resolver.CustomArgumentResolver"/>
                mvc:argument-resolvers>
            mvc:annotation-driven>

• springboot项目中配置

  @SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
  @ImportResource({"classpath*:dispatcher-servlet.xml"})
  public class LiosBootApplication extends WebMvcConfigurerAdapter {
      public static void main(String[] args) {
          SpringApplication.run(LiosBootApplication.class, args);
      }
      @Override
      public void addArgumentResolvers(List argumentResolvers) {
       super.addArgumentResolvers(argumentResolvers);
       argumentResolvers.add(new CustomArgumentResolver());
          }
      }