java 첨삭 JDBC 패키지 클래스 검사 (일반 패키지)

    

package com.massky.connsqlserver;

import android.content.Context;
import android.content.SharedPreferences;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

//     
public class BaseDao {
    Class clazz;

    public BaseDao() {
        Type type = this.getClass().getGenericSuperclass();
        Type[] types = ((ParameterizedType) type).getActualTypeArguments();
        clazz = (Class) types[0];
    }


    //      
    public List queryList(T t) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        String sql = getQuerySql(t);
        List list = new ArrayList();
        try {
            conn = DBUtilNew.getConn();
            ps = conn.prepareStatement(sql);
            common_excute(t, ps);
            rs = ps.executeQuery();
            ResultSetMetaData metaData = rs.getMetaData();
            int count = metaData.getColumnCount();
            while (rs.next()) {
                T obj = (T) clazz.newInstance();
                for (int i = 0; i < count; i++) {
                    String fieldName = metaData.getColumnName(i + 1);
                    Field field = clazz.getDeclaredField(fieldName);
                    Method method = clazz.getMethod(getSetter(fieldName), field.getType());
                    method.invoke(obj, rs.getObject(i + 1));
                }
                list.add(obj);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtilNew.close(rs, ps, conn);
        }
        return list;
    }


    //      
    public void deleteList(T t) {
        Connection conn = null;
        PreparedStatement ps = null;
        String sql = getDeleteSql(t);
        try {
            conn = DBUtilNew.getConn();
            ps = conn.prepareStatement(sql);
            common_excute(t, ps);
            ps.execute();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtilNew.close(ps, conn);
        }
    }

    /**
     *       
     *
     * @param t
     * @param ps
     * @throws IllegalAccessException
     * @throws NoSuchMethodException
     * @throws InvocationTargetException
     * @throws SQLException
     */
    private void common_excute(T t, PreparedStatement ps) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException, SQLException {
        Field[] fields = clazz.getDeclaredFields();
        int c = 1;
        for (int i = 0; i < fields.length - 2; i++) {
            fields[i].setAccessible(true);
            Class> type = fields[i].getType();
            //  
            if (fields[i].get(t) != null) {
                if ("int".equals(type.getName()) && (int) fields[i].get(t) == -1)
                    continue;
                String fieldName = fields[i].getName();
                Method method = clazz.getMethod(getGetter(fieldName));
                Object obj = method.invoke(t);
                ps.setObject(c, obj);
                fields[i].setAccessible(false);
                c++;
            }
        }
    }

    /** 
          *   、  、  
          * @param sql 
          * @param params 
          * @return 
          * @throws SQLException 
          */
    public  boolean updateByPreparedStatement(String sql,List