Java SQL ResultSet Read getListFromRS(Class clazz, ResultSet rs)

Description

get List From RS

License

Apache License

Declaration

public static <T> List<T> getListFromRS(Class<T> clazz, ResultSet rs) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.util.ArrayList;
import java.util.List;

public class Main {
    public static <T> List<T> getListFromRS(Class<T> clazz, ResultSet rs) {
        return getListFromRS(clazz, rs, false);
    }//from   w ww  .  j a v a 2s . co m

    public static <T> List<T> getListFromRS(Class<T> clazz, ResultSet rs, Boolean firstOnly) {
        Field field = null;
        List<T> lists = new ArrayList<T>();

        try {
            ResultSetMetaData rsmd = rs.getMetaData();
            int counts = rsmd.getColumnCount();
            while (rs.next()) {
                T t = clazz.newInstance();
                for (int i = 0; i < counts; i++) {
                    String elename = firstLowerCase(rsmd.getColumnName(i + 1));
                    field = clazz.getDeclaredField(elename);

                    Class<?> beanType = field.getType();

                    Object value = rs.getObject(elename);

                    if (value != null) {

                        Class<?> dbType = value.getClass();

                        if (dbType == java.sql.Timestamp.class && beanType == java.util.Date.class) {
                            value = new java.util.Date(((java.sql.Timestamp) value).getTime());
                        } else if (dbType == java.math.BigDecimal.class && beanType == double.class) {
                            value = new Double(value.toString());
                        } else if (dbType == java.math.BigDecimal.class && beanType == int.class) {
                            value = new Integer(value.toString());
                        }
                    }

                    String setMethodName = "set" + firstUpperCase(elename);
                    Method m = t.getClass().getMethod(setMethodName, beanType);

                    m.invoke(t, value);
                }

                lists.add(t);
                if (firstOnly)
                    break;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return lists;
    }

    public static String firstLowerCase(String old) {
        return old.substring(0, 1).toLowerCase() + old.substring(1);
    }

    public static String firstUpperCase(String old) {
        return old.substring(0, 1).toUpperCase() + old.substring(1);
    }
}

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