package com.jiang.DB;

import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.sql.RowSet;

public class GetData {
     public static String getJson(String tableName,String select,String where,String orderby,int pageIndex,int pageCount){
         StringBuilder sb=new StringBuilder();
         sb.append("select "+select+" from "+tableName);
         if(!"".equals(where)){
        	 sb.append(" ");
        	 if(where.startsWith("where")){
        		 sb.append(" "+where);
        	 }else{
        		 sb.append(" where "+where);
        	 }
         }
         sb.append(" "+orderby+" ");
         int temp=(pageIndex-1)*pageCount;
         sb.append(" limit "+temp+","+pageCount);
    	 RowSet rt=DBop.search(sb.toString());
    	 //求数据总条目数
         int rowNum=0;
         rowNum=DBop.getNum(tableName,where);
    	 return RowSetToJson(rt,rowNum,pageCount);
     }
     
     /*
      * @param count 数据总条目数
      * @param pageCount 每页显示数据数
      * */
     private static String RowSetToJson(RowSet rt,int count,int pageCount){
    	 ResultSetMetaData rm=null;
    	 StringBuilder sb=new StringBuilder();
    	 try {
			 rm=rt.getMetaData();
			 sb.append("{\"pageCount\":\""+count+"\",\"pageData\":[");
			 int columNum=rm.getColumnCount();
			 List<String> list=new ArrayList<String>();
			 for(int i=0;i<columNum;i++){
				 list.add(rm.getColumnName(i+1));
			 }
			 
			 for(int i=0;i<pageCount&&rt.next();i++){
				 sb.append("{");
				 for(int j=0;j<list.size();j++){
					 if(j!=list.size()-1){
						 sb.append("\""+list.get(j)+"\":\""+rt.getString(list.get(j))+"\",");
					 }else{
						 sb.append("\""+list.get(j)+"\":\""+rt.getString(list.get(j))+"\"");
					 }
				 }
				 if(i!=pageCount-1){
					 sb.append("},");
				 }else{
					 sb.append("}");
				 } 
			 }
			 sb.append("]}");
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
    	 return sb.toString();
     }
     
     public static void main(String[] args){
    	 String temp=GetData.getJson("pagetest", "*", "","order by id_t", 1000, 10);
    	 System.out.println(temp);
     }
}