Spring mvc3 jackson输出null为空字符串、单引号、字段和数字加引号问题

最近做项目，和其他人商议用json通信，因为对方是php程序员，php的编码风格对于java程序员来说就是变态，有几点变态需求：

1、json requestbody 输要用单引号(jackson默认是双引号，单引号直接报错)

2、responsebody数字输出要加引号，字段名要加引号。

3、null值为空串

 

于是查阅官方文档，终于找到方法，有点小搓，直接在Converter对象上注入一个自定义类ObjectMappingCustomer：

 <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">   
        <property name="messageConverters">   
            <list>   
                <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
                    <property name="supportedMediaTypes">
                        <list>
                            <value>text/plain;charset=UTF-8</value>
                            <value>application/json;charset=UTF-8</value>
                        </list>
                    </property>
                    <property name="objectMapper">
                        <bean class="com.wuliaolll.util.ObjectMappingCustomer"></bean>
                    </property>
                </bean>   
            </list>   
        </property>   
    </bean>   

 

package com.wuliaolll.util;

import java.io.IOException;

import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializerProvider;

public class ObjectMappingCustomer extends ObjectMapper
{

    public ObjectMappingCustomer()
    {
        super();
        // 允许单引号
        this.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
        // 字段和值都加引号
        this.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        // 数字也加引号
        this.configure(JsonGenerator.Feature.WRITE_NUMBERS_AS_STRINGS, true);
        this.configure(JsonGenerator.Feature.QUOTE_NON_NUMERIC_NUMBERS, true);
        // 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("");
            }
        });

    }
}