JDBC 批量处理语句提高处理速度

当需要成批插入或者更新记录时。可以采用 Java 的批量更新机制，这一机制允许多条语句一次性提交给数据库批量处理。通常这种情况下比单独提交处理更有效率。

    JDBC 的批量处理语句包括以下两个方法：

    1）addBatch（String）：添加需要批量处理的 SQL 语句或是参数

    2）executeBatch（）：执行批量处理语句

    通常会遇到两种批量执行 SQL 语句的情况：

    1）多条 SQL 语句的批量处理

    2）一个 SQL 语句的批量传参

 

@Test
 public void testBatch(){
  Connection connection = null;
  PreparedStatement preparedStatement = null;
  String sql = null; 
  try {  
   connection = JDBCTools.GetConnection();
   JDBCTools.beginTransaction(connection);
   sql = "INSERT INTO mytable VALUES(?, ?)";
   preparedStatement = connection.prepareStatement(sql);
   Date date = new Date(new Date().getTime());
   
   long begin = System.currentTimeMillis();
   for(int i = 0; i < 10000; i++){
    preparedStatement.setInt(1, i + 1);
    preparedStatement.setString(2, "name_" + i);
    
    //积攒 SQL
    preparedStatement.addBatch();
    //当积攒到一定程度就统一的执行一次，并且清空先前积攒的 SQL
    if((i + 1) % 300 == 0){
     preparedStatement.executeBatch();
     preparedStatement.clearBatch();
    }
   }
   //若总条数不是批量数值的整数倍，则还需要在额外的执行一次
   if(10000 % 300 != 0){
    preparedStatement.executeBatch();
    preparedStatement.clearBatch();
   }
   
   long end = System.currentTimeMillis();
   System.out.println("Time: " + (end - begin));//746
   JDBCTools.commit(connection);
   
  } catch (Exception e) {
   e.printStackTrace();
   JDBCTools.rollback(connection);
  }finally{
   JDBCTools.release(null, preparedStatement, connection);
  }
 }
 @Test
 public void testBatchWithPreparedStatement(){
  Connection connection = null;
  PreparedStatement preparedStatement = null;
  String sql = null; 
  try {  
   connection = JDBCTools.GetConnection();
   JDBCTools.beginTransaction(connection);
   sql = "INSERT INTO mytable VALUES(?, ?)";
   preparedStatement = connection.prepareStatement(sql);
   Date date = new Date(new Date().getTime());
   
   long begin = System.currentTimeMillis();
   for(int i = 0; i < 10000; i++){
    preparedStatement.setInt(1, i + 1);
    preparedStatement.setString(2, "name_" + i);
    preparedStatement.executeUpdate();
   }
   long end = System.currentTimeMillis();
   System.out.println("Time: " + (end - begin));//1041
   JDBCTools.commit(connection);
   
  } catch (Exception e) {
   e.printStackTrace();
   JDBCTools.rollback(connection);
  }finally{
   JDBCTools.release(null, preparedStatement, connection);
  }
 }

 @Test
 public void testJDBCBatch() {
  Connection connection = null;
  Statement statement = null;
  String sql = null;
   try {
   connection = JDBCTools.GetConnection();
   JDBCTools.beginTransaction(connection);
   statement = connection.createStatement();
   
   long begin = System.currentTimeMillis();
   for(int i = 0; i < 10000; i++){
    sql = "INSERT INTO mytable VALUES(" + (i + 1) + ", '"+ "name_" + i +"')";
    statement.executeUpdate(sql);
   }
   long end = System.currentTimeMillis();
   System.out.println("Time: " + (end - begin));//4161
   JDBCTools.commit(connection);
   
  } catch (Exception e) {
   e.printStackTrace();
   JDBCTools.rollback(connection);
  }finally{
   JDBCTools.release(null, statement, connection);
  }
 }

public class JDBCTools {
 //提交事務
  public static void commit(Connection connection){
   if(connection != null){
    try {
     connection.commit();
    } catch (SQLException e) {
     e.printStackTrace();
    }
   }
  }
  //回滾 事務
  public static void rollback(Connection connection){
  
   if(connection != null){
    try {
     connection.rollback();
    } catch (SQLException e) {
     e.printStackTrace();
    }
   }
  }

//开始事务

  public static void beginTransaction(Connection connection){
   if(connection != null){
    try {
     connection.setAutoCommit(false);
    } catch (SQLException e) {
     e.printStackTrace();
    }
   }
  }

//关闭资源

  public static void release(ResultSet rs, Statement statement,
   Connection conn) {
  if (rs != null) {
   try {
    rs.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
  if (statement != null)
   try {
    statement.close();
   } catch (Exception e2) {
    e2.printStackTrace();
   }
  if (conn != null)
   try {
    conn.close();
   } catch (Exception e2) {
    e2.printStackTrace();
   }
 }

  /*
  * 1. 获取连接的方法 通过读配置文件从数据库服务器获取一个连接
  */
 public static Connection GetConnection() throws Exception {
  String driverClass = null;
  String jdbcUrl = null;
  String user = null;
  String password = null;

  InputStream in = JDBCTools.class.getClassLoader().getResourceAsStream(
    "jdbc.properties");
  Properties properties = new Properties();
  properties.load(in);
  driverClass = properties.getProperty("driver");
  jdbcUrl = properties.getProperty("jdbcUrl");
  user = properties.getProperty("user");
  password = properties.getProperty("password");

  Driver driver = (Driver) Class.forName(driverClass).newInstance();

  Properties info = new Properties();
  info.put("user", user);
  info.put("password", password);
  Connection connection = driver.connect(jdbcUrl, info);

  return connection;
 }
}