JDBC批量插入数据优化,使用addBatch和executeBatch

转载请注明出处：http://blog.csdn.net/linglongxin24/article/details/53769957
本文出自【DylanAndroid的博客】

---

JDBC批量插入数据优化,使用addBatch和executeBatch

在之前的玩转JDBC打造数据库操作万能工具类JDBCUtil，加入了高效的数据库连接池，利用了参数绑定有效防止SQL注入
中其实忽略了一点，那就是SQL的批量插入的问题，如果来个for循环，执行上万次，肯定会很慢，那么，如何去优化呢？

一.用 preparedStatement.addBatch()配合preparedStatement.executeBatch()去批量插入

 /**
     * 执行数据库插入操作
     *
     * @param datas     插入数据表中key为列名和value为列对应的值的Map对象的List集合
     * @param tableName 要插入的数据库的表名
     * @return 影响的行数
     * @throws SQLException SQL异常
     */
    public static int insertAll(String tableName, List> datas) throws SQLException {
        /**影响的行数**/
        int affectRowCount = -1;
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        try {
            /**从数据库连接池中获取数据库连接**/
            connection = DBConnectionPool.getInstance().getConnection();


            Map valueMap = datas.get(0);
            /**获取数据库插入的Map的键值对的值**/
            Set keySet = valueMap.keySet();
            Iterator iterator = keySet.iterator();
            /**要插入的字段sql，其实就是用key拼起来的**/
            StringBuilder columnSql = new StringBuilder();
            /**要插入的字段值，其实就是？**/
            StringBuilder unknownMarkSql = new StringBuilder();
            Object[] keys = new Object[valueMap.size()];
            int i = 0;
            while (iterator.hasNext()) {
                String key = iterator.next();
                keys[i] = key;
                columnSql.append(i == 0 ? "" : ",");
                columnSql.append(key);

                unknownMarkSql.append(i == 0 ? "" : ",");
                unknownMarkSql.append("?");
                i++;
            }
            /**开始拼插入的sql语句**/
            StringBuilder sql = new StringBuilder();
            sql.append("INSERT INTO ");
            sql.append(tableName);
            sql.append(" (");
            sql.append(columnSql);
            sql.append(" )  VALUES (");
            sql.append(unknownMarkSql);
            sql.append(" )");

            /**执行SQL预编译**/
            preparedStatement = connection.prepareStatement(sql.toString());
            /**设置不自动提交，以便于在出现异常的时候数据库回滚**/
            connection.setAutoCommit(false);
            System.out.println(sql.toString());
            for (int j = 0; j < datas.size(); j++) {
                for (int k = 0; k < keys.length; k++) {
                    preparedStatement.setObject(k + 1, datas.get(j).get(keys[k]));
                }
                preparedStatement.addBatch();
            }
            int[] arr = preparedStatement.executeBatch();
            connection.commit();
            affectRowCount = arr.length;
            System.out.println("成功了插入了" + affectRowCount + "行");
            System.out.println();
        } catch (Exception e) {
            if (connection != null) {
                connection.rollback();
            }
            e.printStackTrace();
            throw e;
        } finally {
            if (preparedStatement != null) {
                preparedStatement.close();
            }
            if (connection != null) {
                connection.close();
            }
        }
        return affectRowCount;
    }

二.实验论证

1.普通的插入方法一次性插入10000条数据所消耗的时间

 private static void testAll1() {

        long start = System.currentTimeMillis();
        try {
            for (int i = 0; i < 10000; i++) {
                Map map = new HashMap<>();
                map.put("emp_id", 1013);
                map.put("name", "JDBCUtil测试");
                map.put("job", "developer");
                map.put("salary", 10000);
                map.put("hire_date", new java.sql.Date(System.currentTimeMillis()));
                DBUtil.insert("emp_test3", map);
            }
            System.out.println("共耗时" + (System.currentTimeMillis() - start));
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

• 打印结果

共耗时44110

2.优化后的方法一次性插入10000条数据所消耗的时间

  private static void testAll2() {
        List> datas = new ArrayList<>();
        for (int i = 0; i < 10000; i++) {
            Map map = new HashMap<>();
            map.put("emp_id", 1013);
            map.put("name", "JDBCUtil测试");
            map.put("job", "developer");
            map.put("salary", 10000);
            map.put("hire_date", new java.sql.Date(System.currentTimeMillis()));
            datas.add(map);
        }
        try {
            long start = System.currentTimeMillis();
            DBUtil.insertAll("emp_test3", datas);
            System.out.println("共耗时" + (System.currentTimeMillis() - start));
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

• 打印结果

共耗时649

3.DBUtil的完整代码

package cn.bluemobi.dylan.util;

import com.sun.istack.internal.Nullable;

import java.sql.*;
import java.util.*;
import java.util.regex.Pattern;

/**
 * 数据库JDBC连接工具类
 * Created by yuandl on 2016-12-16.
 */
public class DBUtil {

    /**
     * 执行数据库插入操作
     *
     * @param valueMap  插入数据表中key为列名和value为列对应的值的Map对象
     * @param tableName 要插入的数据库的表名
     * @return 影响的行数
     * @throws SQLException SQL异常
     */
    public static int insert(String tableName, Map valueMap) throws SQLException {

        /**获取数据库插入的Map的键值对的值**/
        Set keySet = valueMap.keySet();
        Iterator iterator = keySet.iterator();
        /**要插入的字段sql，其实就是用key拼起来的**/
        StringBuilder columnSql = new StringBuilder();
        /**要插入的字段值，其实就是？**/
        StringBuilder unknownMarkSql = new StringBuilder();
        Object[] bindArgs = new Object[valueMap.size()];
        int i = 0;
        while (iterator.hasNext()) {
            String key = iterator.next();
            columnSql.append(i == 0 ? "" : ",");
            columnSql.append(key);

            unknownMarkSql.append(i == 0 ? "" : ",");
            unknownMarkSql.append("?");
            bindArgs[i] = valueMap.get(key);
            i++;
        }
        /**开始拼插入的sql语句**/
        StringBuilder sql = new StringBuilder();
        sql.append("INSERT INTO ");
        sql.append(tableName);
        sql.append(" (");
        sql.append(columnSql);
        sql.append(" )  VALUES (");
        sql.append(unknownMarkSql);
        sql.append(" )");
        return executeUpdate(sql.toString(), bindArgs);
    }

    /**
     * 执行数据库插入操作
     *
     * @param datas     插入数据表中key为列名和value为列对应的值的Map对象的List集合
     * @param tableName 要插入的数据库的表名
     * @return 影响的行数
     * @throws SQLException SQL异常
     */
    public static int insertAll(String tableName, List> datas) throws SQLException {
        /**影响的行数**/
        int affectRowCount = -1;
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        try {
            /**从数据库连接池中获取数据库连接**/
            connection = DBConnectionPool.getInstance().getConnection();


            Map valueMap = datas.get(0);
            /**获取数据库插入的Map的键值对的值**/
            Set keySet = valueMap.keySet();
            Iterator iterator = keySet.iterator();
            /**要插入的字段sql，其实就是用key拼起来的**/
            StringBuilder columnSql = new StringBuilder();
            /**要插入的字段值，其实就是？**/
            StringBuilder unknownMarkSql = new StringBuilder();
            Object[] keys = new Object[valueMap.size()];
            int i = 0;
            while (iterator.hasNext()) {
                String key = iterator.next();
                keys[i] = key;
                columnSql.append(i == 0 ? "" : ",");
                columnSql.append(key);

                unknownMarkSql.append(i == 0 ? "" : ",");
                unknownMarkSql.append("?");
                i++;
            }
            /**开始拼插入的sql语句**/
            StringBuilder sql = new StringBuilder();
            sql.append("INSERT INTO ");
            sql.append(tableName);
            sql.append(" (");
            sql.append(columnSql);
            sql.append(" )  VALUES (");
            sql.append(unknownMarkSql);
            sql.append(" )");

            /**执行SQL预编译**/
            preparedStatement = connection.prepareStatement(sql.toString());
            /**设置不自动提交，以便于在出现异常的时候数据库回滚**/
            connection.setAutoCommit(false);
            System.out.println(sql.toString());
            for (int j = 0; j < datas.size(); j++) {
                for (int k = 0; k < keys.length; k++) {
                    preparedStatement.setObject(k + 1, datas.get(j).get(keys[k]));
                }
                preparedStatement.addBatch();
            }
            int[] arr = preparedStatement.executeBatch();
            connection.commit();
            affectRowCount = arr.length;
            System.out.println("成功了插入了" + affectRowCount + "行");
            System.out.println();
        } catch (Exception e) {
            if (connection != null) {
                connection.rollback();
            }
            e.printStackTrace();
            throw e;
        } finally {
            if (preparedStatement != null) {
                preparedStatement.close();
            }
            if (connection != null) {
                connection.close();
            }
        }
        return affectRowCount;
    }

    /**
     * 执行更新操作
     *
     * @param tableName 表名
     * @param valueMap  要更改的值
     * @param whereMap  条件
     * @return 影响的行数
     * @throws SQLException SQL异常
     */
    public static int update(String tableName, Map valueMap, Map whereMap) throws SQLException {
        /**获取数据库插入的Map的键值对的值**/
        Set keySet = valueMap.keySet();
        Iterator iterator = keySet.iterator();
        /**开始拼插入的sql语句**/
        StringBuilder sql = new StringBuilder();
        sql.append("UPDATE ");
        sql.append(tableName);
        sql.append(" SET ");

        /**要更改的的字段sql，其实就是用key拼起来的**/
        StringBuilder columnSql = new StringBuilder();
        int i = 0;
        List