在SpringMVC中，可以通过在<mvc:annotation-driven>中配置<mvc:message-converters>，把null值统一转换为空字符串，解决这个问题。下面以JSon交互的方式为例说明如何实现：
第一步：创建一个ObjectMapper
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package
com.xjj.anes.mvc.converter;
import
java.io.IOException;
import
com.fasterxml.jackson.core.JsonGenerator;
import
com.fasterxml.jackson.core.JsonProcessingException;
import
com.fasterxml.jackson.databind.JsonSerializer;
import
com.fasterxml.jackson.databind.ObjectMapper;
import
com.fasterxml.jackson.databind.SerializerProvider;
/**
* @description: 转换null对象为空字符串
*/
public
class JsonObjectMapper extends ObjectMapper {
private
static final long serialVersionUID = 1L;
public
JsonObjectMapper() {
super
();
// 空值处理为空串
this
.getSerializerProvider().setNullValueSerializer(
new
JsonSerializer<Object>() {
@Override
public
void serialize(Object value, JsonGenerator jg, SerializerProvider sp) throws IOException, JsonProcessingException {
jg.writeString(
""
);
}
});
}
}
|
第二步：在SpringMVC配置文件中，把新建的ObjectMapper注入给MappingJackson2HttpMessageConverter
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<!-- 注册RequestMappingHandlerMapping 和RequestMappingHandlerAdapter 两个bean。-->
<mvc:annotation-driven>
<mvc:message-converters>
<bean
class
=
"org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"
>
<property name=
"objectMapper"
>
<bean
class
=
"com.xjj.anes.mvc.converter.JsonObjectMapper"
></bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
|
在SpringMVC中，可以通过在<mvc:annotation-driven>中配置<mvc:message-converters>，把null值统一转换为空字符串，解决这个问题。下面以JSon交互的方式为例说明如何实现：
第一步：创建一个ObjectMapper
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
package
com.xjj.anes.mvc.converter;
import
java.io.IOException;
import
com.fasterxml.jackson.core.JsonGenerator;
import
com.fasterxml.jackson.core.JsonProcessingException;
import
com.fasterxml.jackson.databind.JsonSerializer;
import
com.fasterxml.jackson.databind.ObjectMapper;
import
com.fasterxml.jackson.databind.SerializerProvider;
/**
* @description: 转换null对象为空字符串
*/
public
class JsonObjectMapper extends ObjectMapper {
private
static final long serialVersionUID = 1L;
public
JsonObjectMapper() {
super
();
// 空值处理为空串
this
.getSerializerProvider().setNullValueSerializer(
new
JsonSerializer<Object>() {
@Override
public
void serialize(Object value, JsonGenerator jg, SerializerProvider sp) throws IOException, JsonProcessingException {
jg.writeString(
""
);
}
});
}
}
|
第二步：在SpringMVC配置文件中，把新建的ObjectMapper注入给MappingJackson2HttpMessageConverter
|
1
2
3
4
5
6
7
8
9
10
|
<!-- 注册RequestMappingHandlerMapping 和RequestMappingHandlerAdapter 两个bean。-->
<mvc:annotation-driven>
<mvc:message-converters>
<bean
class
=
"org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"
>
<property name=
"objectMapper"
>
<bean
class
=
"com.xjj.anes.mvc.converter.JsonObjectMapper"
></bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
|