spring mvc json 问题

applicationContext.xml

 1 <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
 2         <property name="messageConverters">
 3             <list>
 4                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
 5                    <property name="supportedMediaTypes">
 6                        <list>
 7                            <value>text/plain;charset=UTF-8</value>
 8                            <value>application/json;charset=UTF-8</value>
 9                        </list>
10                    </property>
11                    <property name="objectMapper">
12                        <bean class="com.charmyin.cmstudio.common.utils.ObjectMappingCustomer"></bean>
13                    </property>
14                </bean>
15             </list>
16         </property>
17     </bean>

此处我也尝试了

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> ...... </bean>

ObjectMappingCustomer.java

 1 package com.charmyin.cmstudio.common.utils;
 2
 3
 4 import java.io.IOException;
 5
 6 import com.fasterxml.jackson.databind.JsonSerializer;
 7 import com.fasterxml.jackson.databind.ObjectMapper;
 8 import com.fasterxml.jackson.core.JsonGenerator;
 9 import com.fasterxml.jackson.core.JsonParser;
10 import com.fasterxml.jackson.core.JsonProcessingException;
11 import com.fasterxml.jackson.databind.SerializerProvider;
12
13     public class ObjectMappingCustomer extends ObjectMapper
14
15     {
16
17         /**
18          *
19          */
20         private static final long serialVersionUID = 1L;
21
22
23
24         public ObjectMappingCustomer()
25
26         {
27 //
28             super();
29
30             // 允许单引号
31
32             this.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
33
34             // 字段和值都加引号
35
36             this.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
37
38             // 数字也加引号
39
40             this.configure(JsonGenerator.Feature.WRITE_NUMBERS_AS_STRINGS, true);
41
42             this.configure(JsonGenerator.Feature.QUOTE_NON_NUMERIC_NUMBERS, true);
43 //
44 //            // 空值处理为空串
45 //
46             SerializerProvider sp = (SerializerProvider) this.getSerializerProvider();
47
48             sp.setNullValueSerializer(new JsonSerializer<Object>(){
49
50
51
52                 @Override
53
54                 public void serialize(Object value, JsonGenerator jg,
55
56                         SerializerProvider sp) throws IOException,
57
58                         JsonProcessingException {
59
60                      jg.writeString("");
61
62                 }
63
64
65
66             });
67 //
68 //
69 //
70         }
71
72     }

输出的json

{
    "rows": [
        {
            "pageVO": null,
            "praId": "bffa397b245849909a9c2af4e74e007d19a1e6cb",
            "creatorId": 248,
            "creatorName": "stu123",
            "finalReport": null
      }
    ]
}