Fastjson中writeJSONString方法具有什么功能呢？

writeJSONString方法的功能

 将实体信息直接采用json字符串的形式写入到流中

writeJSONString方法源码

package com.alibaba.fastjson;

public abstract class JSON {
   public static final int writeJSONString(OutputStream os, /
                                             Object object, /
                                             SerializerFeature... features) throws IOException;

    public static final int writeJSONString(OutputStream os, /
                                             Charset charset, //  
                                             Object object, // 
                                             SerializerFeature... features) throws IOException;

   public static final int writeJSONString(Writer os, // 
                                             Object object, // 
                                             SerializerFeature... features) throws IOException;
}

import com.alibaba.fastjson;
import java.nio.charset.Charset;
class Model {
    public int value;
}

Model model = new Model();
model.value = 8998;

OutputStream os = ...;
JSON.writeJSONString(os, model);
JSON.writeJSONString(os, Charset.from("GB18030"), model);

Writer writer = ...;
JSON.writeJSONString(os, model);