人人人人人你人人人人人,精品免费一区二区,一级片少妇

springmvc @RequestBody String類型參數

通過如下配置：

 <bean id="mappingJacksonHttpMessageConverter"
        class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
      <property name="supportedMediaTypes">
          <list>
              <value>text/html;charset=UTF-8</value>
              <value>application/json;charset=UTF-8</value>
          </list>
      </property>
  </bean>
  <!-- 啟動SpringMVC的注解功能，完成請求和注解POJO的映射 -->
  <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
  <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
      <property name="messageConverters">
          <list>
              <ref bean="mappingJacksonHttpMessageConverter"/>
              <!-- JSON轉換器 -->
          </list>
      </property>
  </bean>

在spring mvc的Controller層使用@RequestBody接收Content-Type為application/json的數據時，默認支持Map方式和對象方式參數

@RequestMapping(value = "/[code]/saveUser", method = RequestMethod.POST)
  @ResponseBody
  public JsonResult saveUser(@PathVariable("code") Integer code, @RequestBody Map<String, Object> datas,@RequestBody User user) {
  。。。
  }

如果是一個參數時也需要用個Map或者對象處理，使用String會報解析錯誤，具體看：AbstractJackson2HttpMessageConverter的方法read(Type type, Class

@Override
  public Object read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)
          throws IOException, HttpMessageNotReadableException {
      JavaType javaType = getJavaType(type, contextClass);
      return readJavaType(javaType, inputMessage);
  }
  private Object readJavaType(JavaType javaType, HttpInputMessage inputMessage) {
      try {
          return this.objectMapper.readValue(inputMessage.getBody(), javaType);
      }
      catch (IOException ex) {
          throw new HttpMessageNotReadableException("Could not read JSON: " + ex.getMessage(), ex);
      }
  }

為了讓@RequestBody支持String參數(目前只支持接收單個參數)

重寫org.springframework.http.converter.json.MappingJackson2HttpMessageConverter類

package com.test.converter.json
import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.LinkedHashMap;
/**
* 處理@RequestBody注解為String的情況，只支持接收單個參數的情況
* Created by test
* Date:2017/1/4
* Time:17:33
*/
public class CustomerMappingJackson2HttpMessageConverter extends MappingJackson2HttpMessageConverter {
  @Override
  protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
      Class<?> deseriClazz = getClazz(clazz);
      Object param = super.readInternal(deseriClazz, inputMessage);
      return getTrueObject(clazz, param);
  }
  @Override
  public Object read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)
          throws IOException, HttpMessageNotReadableException {
      Type deseriType = getType(type);
      Object param = super.read(deseriType, contextClass, inputMessage);
      return getTrueObject(type, param);
  }
  /**
   * 通過返回參數類型決定是否處理參數，如果是String類型的參數，將解析后的HashMap里的值返回（只支持單個參數）
   *
   * @param type  返回參數類型
   * @param param 參數值
   * @return 實際參數值
   */
  private Object getTrueObject(Type type, Object param) {
      if (type == String.class) {
          Object backParam = null;
          if (param != null && param instanceof LinkedHashMap) {
              LinkedHashMap paramMap = (LinkedHashMap) param;
              if (paramMap.size() == 1) {
                  backParam = paramMap.get(paramMap.keySet().iterator().next());
              }
          }
          param = backParam;
      }
      return param;
  }
  /**
   * 獲取解析參數用的Type
   *
   * @param type 參數類型
   * @return
   */
  private Type getType(Type type) {
      Type deseriClazz;
      if (type == String.class) {
          //jackson不支持String默認用LinkedHashMap
          deseriClazz = LinkedHashMap.class;
      } else {
          deseriClazz = type;
      }
      return deseriClazz;
  }
  /**
   * 獲取解析參數用的Type
   * @param clazz 參數類型
   * @return
   */
  private Class<?> getClazz(Class<?> clazz) {
      Class<?> deseriClazz;
      if (clazz == String.class) {
          //jackson不支持String默認用LinkedHashMap
          deseriClazz = LinkedHashMap.class;
      } else {
          deseriClazz = clazz;
      }
      return deseriClazz;
  }
}

spring mvc xml配置文件修改：

<bean id="mappingJacksonHttpMessageConverter"
        class="com.test.converter.json.CustomerMappingJackson2HttpMessageConverter">
      <property name="supportedMediaTypes">
          <list>
              <value>text/html;charset=UTF-8</value>
              <value>application/json;charset=UTF-8</value>
          </list>
      </property>
  </bean>

Controller層：

@RequestMapping(value = "/delUser", method = RequestMethod.POST)
  @ResponseBody
  public JsonResult delUser(@RequestBody String id) {
  。。。
  }

springmvc用Map接收請求參數分析

第一種情況，什么也不設置，無參數傳遞

注解為 @Controller @RequestMapping

springmvc @RequestBody String類型參數的使用

可以看到傳遞的為SpringMVC的BindingAwareModelMap類型，SpringMVC中的隱含模型就是這個類型，其作用域等價于 request 域，當添加Model、ModelMap參數時，SpringMVC實際傳入的就是這個隱含模型；向這個隱含模型種設置值后，在返回的頁面中就能通過request域取值。