resultSet 与 实体类 与 JSON之间的相互转化

package com.eabax.plugin.yundada.utils;

 

import java.lang.reflect.Method;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

 

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

 

public class ResultSetTool {

    /**

     * 将resultSet转化为实体类（实体字段全为String类型）

     * @param rs

     * @param dto

     * @return

     * @throws Exception

     */

    public static <T> T bindDataToDTO(ResultSet rs, T dto) throws Exception { 

           

        //取得Method方法  

        Method[] methods = dto.getClass().getMethods(); 

   

        //取得ResultSet的列名  

        ResultSetMetaData rsmd = rs.getMetaData();  

        int columnsCount = rsmd.getColumnCount();  

        String[] columnNames = new String[columnsCount];  

        for (int i = 0; i < columnsCount; i++) {  

            columnNames[i] = rsmd.getColumnLabel(i + 1);  

        } 

   

        //遍历ResultSet  

        while (rs.next()) {  

            //反射, 从ResultSet绑定到JavaBean  

            for (int i = 0; i < columnNames.length; i++) {  

                //取得Set方法  

                String setMethodName = "set" + columnNames[i];  

                //遍历Method  

                for (int j = 0; j < methods.length; j++) {  

                    if (methods[j].getName().equalsIgnoreCase(setMethodName)) {  

                        setMethodName = methods[j].getName();  

                        Object value = rs.getObject(columnNames[i]); 

   

                        //实行Set方法  

                        try {  

                            //JavaBean内部属性和ResultSet中一致时候  

                            if(value != null) {

                                Method setMethod = dto.getClass().getMethod(  

                                        setMethodName, value.getClass());  

                                setMethod.invoke(dto, value);  

                            }

                        } catch (Exception e) {  

                            //JavaBean内部属性和ResultSet中不一致时候，使用String来输入值。  

                            Method setMethod = dto.getClass().getMethod(  

                                    setMethodName, String.class);  

                            setMethod.invoke(dto, value.toString());  

                        }  

                    }  

                }  

            }  

        } 

        return dto;  

    }

     

    /**

     * 将resultSet转化为JSON数组

     * @param rs

     * @return

     * @throws SQLException

     * @throws JSONException

     */

    public static JSONArray resultSetToJsonArry(ResultSet rs) throws SQLException,JSONException 

    { 

       // json数组 

       JSONArray array = new JSONArray(); 

         

       // 获取列数 

       ResultSetMetaData metaData = rs.getMetaData(); 

       int columnCount = metaData.getColumnCount(); 

         

       // 遍历ResultSet中的每条数据 

        while (rs.next()) { 

            JSONObject jsonObj = new JSONObject(); 

              

            // 遍历每一列 

            for (int i = 1; i <= columnCount; i++) { 

                String columnName =metaData.getColumnLabel(i); 

                String value = rs.getString(columnName); 

                jsonObj.put(columnName, value); 

            }  

            array.put(jsonObj);  

        } 

         

       return array; 

    }

     

    /**

     * 将resultSet转化为JSONObject

     * @param rs

     * @return

     * @throws SQLException

     * @throws JSONException

     */

    public static JSONObject resultSetToJsonObject(ResultSet rs) throws SQLException,JSONException 

    { 

       // json对象

        JSONObject jsonObj = new JSONObject();     

       // 获取列数 

       ResultSetMetaData metaData = rs.getMetaData(); 

       int columnCount = metaData.getColumnCount(); 

       // 遍历ResultSet中的每条数据 

        if (rs.next()) { 

            // 遍历每一列 

            for (int i = 1; i <= columnCount; i++) { 

                String columnName =metaData.getColumnLabel(i); 

                String value = rs.getString(columnName); 

                jsonObj.put(columnName, value); 

            }   

        }

       return jsonObj; 

    }

}