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

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
      }
    ]
}