package util;

import java.io.IOException;
import java.io.Writer;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.serializer.ValueFilter;
import com.opensymphony.xwork2.ActionSupport;

/**
 * 将数据转成json数据格式
 *
 */
public class AddJson extends ActionSupport{
	
	private static final long serialVersionUID = 1L;

	private static ValueFilter filter = new ValueFilter() {
        @Override
        public Object process(Object obj, String s, Object v) {
            if (v == null)
                return "";
            return v;
        }
    };
    /**
     * 将JavaBean序列化为JSON文本
     * @param str
     * @throws IOException
     */
	public void toJson(Object str) throws IOException{
		HttpServletResponse response=ServletActionContext.getResponse();
		response.setHeader("Cache-Control", "no-cache");  
		response.setHeader("Pragma", "no-cache");  
		response.setDateHeader("Expires", 0);  
		response.setContentType("text/html;charset=utf-8");
		
		String responseStr = JSON.toJSONString(str,filter,SerializerFeature.WriteNullStringAsEmpty);
		Writer writer = response.getWriter();
		writer.write(responseStr);
		writer.flush();
	}
	/**
	 * 将JavaBean转换为JSONObject
	 * @param str
	 * @throws IOException
	 */
	public void toJsonObj(Object str) throws IOException{
		HttpServletResponse response=ServletActionContext.getResponse();
		response.setHeader("Cache-Control", "no-cache");  
		response.setHeader("Pragma", "no-cache");  
		response.setDateHeader("Expires", 0);  
		response.setContentType("text/html;charset=utf-8");
		
		Object responseStr = JSON.toJSON(str);
		Writer writer = response.getWriter();
		writer.write(responseStr.toString());
		writer.flush();
	}
	/**
	 * 将JavaBean转换为JSONArray
	 * @param list
	 * @throws IOException
	 */
	public <T> void toJsonArray(List<T> list) throws IOException{
		HttpServletResponse response=ServletActionContext.getResponse();
		response.setHeader("Cache-Control", "no-cache");  
		response.setHeader("Pragma", "no-cache");  
		response.setDateHeader("Expires", 0);  
		response.setContentType("text/html;charset=utf-8");
		
		Object obj = JSON.toJSON(list);
		Writer writer = response.getWriter();
		writer.write("{\"length\":"+list.size()+" ,");
		writer.write("\"data\":"+obj.toString()+"}");
		writer.flush();
	}
	
	public <T> void  toJsonList(int len,List<T> list) throws IOException{
        HttpServletResponse response=ServletActionContext.getResponse();
        response.setHeader("Cache-Control", "no-cache");  
        response.setHeader("Pragma", "no-cache");  
        response.setDateHeader("Expires", 0);  
        response.setContentType("text/html;charset=utf-8");
        
        String responseStr = JSON.toJSONString(list,filter);
        Writer writer = response.getWriter();
        //writer.write(responseStr);
        writer.write("{\"length\":"+len+" ,");
        writer.write("\"data\":"+responseStr+"}");
        writer.flush();
    }
}