SpringMVC杂记(1) 使用阿里巴巴的fastjson

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1) 国产开源软件要支持的

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.1</version>
</dependency>

2) spring没有提供相应的HttpMessageConverter可以自己写一个。

package com.alibaba.fastjson.spring.support;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;

import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;

public class MappingFastJsonHttpMessageConverter extends AbstractHttpMessageConverter<Object> {

    public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

    // fastjson特性参数
    private SerializerFeature[] serializerFeature;

    public SerializerFeature[] getSerializerFeature() {
        return serializerFeature;
    }

    public void setSerializerFeature(SerializerFeature[] serializerFeature) {
        this.serializerFeature = serializerFeature;
    }

    public MappingFastJsonHttpMessageConverter() {
        super(new MediaType("application", "json", DEFAULT_CHARSET));
    }

    @Override
    public boolean canRead(Class<?> clazz, MediaType mediaType) {
        // JavaType javaType = getJavaType(clazz);
        // return this.objectMapper.canDeserialize(javaType) &&
        // canRead(mediaType);
        return true;
    }

    @Override
    public boolean canWrite(Class<?> clazz, MediaType mediaType) {
        // return this.objectMapper.canSerialize(clazz) && canWrite(mediaType);
        return true;
    }

    @Override
    protected boolean supports(Class<?> clazz) {
        // should not be called, since we override canRead/Write instead
        throw new UnsupportedOperationException();
    }

    @Override
    protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage)
            throws IOException, HttpMessageNotReadableException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int i;
        while ((i = inputMessage.getBody().read()) != -1) {
            baos.write(i);
        }
        return JSON.parseArray(baos.toString(), clazz);
    }

    @Override
    protected void writeInternal(Object o, HttpOutputMessage outputMessage)
            throws IOException, HttpMessageNotWritableException {
        String jsonString = JSON.toJSONString(o, serializerFeature);
        OutputStream out = outputMessage.getBody();
        out.write(jsonString.getBytes(DEFAULT_CHARSET));
        out.flush();
    }

}

3) 配置

<mvc:annotation-driven>
    <mvc:message-converters register-defaults="true" >
        <bean class="com.alibaba.fastjson.spring.support.MappingFastJsonHttpMessageConverter">
            <property name="supportedMediaTypes" value="application/json" />
            <property name="serializerFeature">
                <array>
                    <value>WriteMapNullValue</value>
                    <value>QuoteFieldNames</value>
                </array>
            </property>
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>