使用JDBC連接MySQL數據庫進行數據插入的時候，特別是大批量數據連續插入（10W+），如何提高效率呢？
在JDBC編程接口中Statement 有兩個方法特別值得注意：
| void addBatch() throws SQLException |
Adds a set of parameters to this PreparedStatement object's batch of commands.
| int[] executeBatch() throws SQLException |
Submits a batch of commands to the database for execution and if all commands execute successfully, returns an array of update counts. The int elements of the array that is returned are ordered to correspond to the commands in the batch, which are ordered according to the order in which they were added to the batch.
通過使用addBatch（）和executeBatch（）這一對方法可以實現批量處理數據。
不過值得注意的是，首先需要在數據庫鏈接中設置手動提交，connection.setAutoCommit(false)，然后在執行Statement之后執行connection.commit()。
| package cyl.demo.ipsearcher; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class DbStoreHelper { private String insert_sql; private String charset; private boolean debug; private String connectStr; private String username; private String password; public DbStoreHelper() { connectStr = "jdbc:mysql://localhost:3306/db_ip"; // connectStr += "?useServerPrepStmts=false&rewriteBatchedStatements=true"; insert_sql = "INSERT INTO tb_ipinfos (iplong1,iplong2,ipstr1,ipstr2,ipdesc) VALUES (?,?,?,?,?)"; charset = "gbk"; debug = true; username = "root"; password = "***"; } public void storeToDb(String srcFile) throws IOException { BufferedReader bfr = new BufferedReader(new InputStreamReader(new FileInputStream(srcFile), charset)); try { doStore(bfr); } catch (Exception e) { e.printStackTrace(); } finally { bfr.close(); } } private void doStore(BufferedReader bfr) throws ClassNotFoundException, SQLException, IOException { Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection(connectStr, username,password); conn.setAutoCommit(false); // 設置手動提交 int count = 0; PreparedStatement psts = conn.prepareStatement(insert_sql); String line = null; while (null != (line = bfr.readLine())) { String[] infos = line.split(";"); if (infos.length < 5) continue; if (debug) { System.out.println(line); } psts.setLong(1, Long.valueOf(infos[0])); psts.setLong(2, Long.valueOf(infos[1])); psts.setString(3, infos[2]); psts.setString(4, infos[3]); psts.setString(5, infos[4]); psts.addBatch(); // 加入批量處理 count++; } psts.executeBatch(); // 執行批量處理 conn.commit(); // 提交 System.out.println("All down : " + count); conn.close(); } } |
