Java JDBC Batch
Java批量处理数据
import java.sql.Connection; import java.sql.PreparedStatement; //import String sql = "insert into employee (name, city, phone) values (?, ?, ?)"; Connection connection = new getConnection(); PreparedStatement ps = connection.prepareStatement(sql); for (Employee employee: employees) { ps.setString(1, employee.getName()); ps.setString(2, employee.getCity()); ps.setString(3, employee.getPhone()); ps.addBatch(); } ps.executeBatch(); ps.close(); connection.close();
Java进行批处理过程中,如果一次处理数据过多就会出现内存溢出错误。解决方法就是为批处理设置BatchSize。
String sql = "insert into employee (name, city, phone) values (?, ?, ?)"; Connection connection = new getConnection(); PreparedStatement ps = connection.prepareStatement(sql); final int batchSize = 1000; int count = 0; for (Employee employee: employees) { ps.setString(1, employee.getName()); ps.setString(2, employee.getCity()); ps.setString(3, employee.getPhone()); ps.addBatch(); if(++count % batchSize == 0) { ps.executeBatch(); } }
// insert remaining records
ps.executeBatch();
ps.close();
connection.close();
Spring Framework也有针对数据库Batch操作,摘抄Spring Framework文档片段
//Spring FrameWork JdbcTemplate public class JdbcActorDao implements ActorDao { private JdbcTemplate jdbcTemplate; public void setDataSource(DataSource dataSource) { this.jdbcTemplate = new JdbcTemplate(dataSource); } //这里返回整数数组,在分批次执行一系列sql,每次都返回一次执行数据库操作影响到的数据条数.如果batch操作失败JDBC驱动则返回-2 public int[] batchUpdate(final List<Actor> actors) { int[] updateCounts = jdbcTemplate.batchUpdate( "update t_actor set first_name = ?, last_name = ? where id = ?", new BatchPreparedStatementSetter() { public void setValues(PreparedStatement ps, int i) throws SQLException { ps.setString(1, actors.get(i).getFirstName()); ps.setString(2, actors.get(i).getLastName()); //longValue() ps.setLong(3, actors.get(i).getId().longValue()); } // 这里设置批处理池容量 public int getBatchSize() { return actors.size(); } } ); return updateCounts; } // ... additional methods }