Java的常见批量操作方法及注意事项

Connection conn = dataSource.getConnection();
try {
    conn.setAutoCommit(false); // 关闭自动提交
    PreparedStatement ps = conn.prepareStatement("INSERT INTO users(name) VALUES (?)");
    
    for (int i = 0; i < 1000; i++) {
        ps.setString(1, "user" + i);
        ps.addBatch(); // 添加到批处理
        if (i % 100 == 0) { // 分批次提交，避免内存溢出
            ps.executeBatch();
            ps.clearBatch();
        }
    }
    ps.executeBatch(); // 执行剩余操作
    conn.commit();     // 提交事务
} catch (BatchUpdateException e) {
    conn.rollback();   // 回滚事务
} finally {
    conn.close();
}

<!-- Mapper XML 中使用 foreach -->
<insert id="batchInsert">
    INSERT INTO users(name) VALUES 
    <foreach item="user" collection="list" separator=",">
        (#{user.name})
    </foreach>
</insert>

// 使用 ExecutorType.BATCH 模式
SqlSession sqlSession = sqlSessionFactory.openSession(ExecutorType.BATCH);
try {
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    for (User user : userList) {
        mapper.insert(user);
    }
    sqlSession.commit(); // 统一提交
} finally {
    sqlSession.close();
}

List<User> users = getUsers();
users.parallelStream()           // 并行流提升速度
     .filter(u -> u.getAge() > 18)
     .forEach(this::processUser); // 批量处理

ExecutorService executor = Executors.newFixedThreadPool(4);
List<Future<?>> futures = new ArrayList<>();

for (List<User> batch : splitIntoBatches(users, 100)) {
    futures.add(executor.submit(() -> processBatch(batch)));
}

// 等待所有任务完成
for (Future<?> future : futures) {
    future.get();
}