idea 将代码块抽取为方法快捷键

小灰灰 2022-05-18 01:18 292阅读 0赞

###  前言 ###

遇到业务逻辑很复杂的模块，有时候一个方法一写就好几百行。这个时候很多代码可以抽成一个方法，从而使业务逻辑很复杂的方法变得易读。当然，你必须要在关键的地方写上注释，方便后面的人维护。  
Idea提供了一个抽取功能，可以将变量、代码块等抽取出来，减少重复代码，提高代码可读性。  
用来重构代码，非常方便快捷。开发效率也会提高！！

###  具体操作 ###

抽取方法的快捷键是 `Ctrl + Alt + M`，其中 M 代表 Method，即方法。  
以下代码分别演示了抽取前，抽取后的变化，可以看出抽取后的代码结构更清晰简单，阅读性更好。

提取前：

// 大转盘 设置某用户下次必中某商品 public void updateTurntableNextAward(Integer userId, Integer awardId, HttpServletRequest request) { //验证奖品 BsTurntableAward award = turntableAwardMapper.selectByPrimaryKey(awardId); if (award == null) { throw new BusiException(E.INVALID_PARAMETER, "奖品不存在"); } if (award.getState() != 1) { throw new BusiException(E.INVALID_PARAMETER, "奖品已停售"); } Jedis jedis = RedisPool.getJedis(); SysUser sysUser = (SysUser) request.getSession().getAttribute(R.LOGIN_USER); try { if (jedis.hexists(Rkey.USER_INFO, userId.toString())) { String hget = jedis.hget(Rkey.TURNTALE_NEXT_AWARD, userId.toString()); if (StringUtils.isEmpty(hget)) { //第一次设置 BsTurntableNextAward record = new BsTurntableNextAward(); record.setAwardId(awardId); record.setState(0); record.setUserId(userId); record.setSysUser(sysUser.getUserName()); turntableNextAwardMapper.insert(record); //修改必中商品的已抽取库存总量：extractAmount + 1 turntableAwardMapper.updateExtractAmountAddOneByAwardId(awardId); //新增操作，redis 对应商品总投放量加一 jedis.hincrBy(Rkey.BRANCH_AWARD_ACTIVE_STOCK, awardId.toString(), 1); //操作数据库 商品对应投放库存加一 //下面这部分可以抽取为1个方法，选中这部分，按下快捷键 Ctrl + Alt + M，填写方法名称即可抽取 Date now = new Date(); String formatDate = DateUtil.formatDate(now, "yyyy-MM-dd HH:mm"); BsTurntableActivity nowPeriodActivity = turntableActivityMapper.queryNowPeriodActivity(formatDate); String curActivityId = nowPeriodActivity.getId().toString(); BsTurntableActivity turntableActivity = new BsTurntableActivity(); turntableActivity.setId(curActivityId; if (nowPeriodActivity.getAwardId1().equals(awardId)) { turntableActivity.setAmount1(nowPeriodActivity.getAmount1() + 1); } else if (nowPeriodActivity.getAwardId2().equals(awardId)) { turntableActivity.setAmount2(nowPeriodActivity.getAmount2() + 1); } else if (nowPeriodActivity.getAwardId3().equals(awardId)) { turntableActivity.setAmount3(nowPeriodActivity.getAmount3() + 1); } else if (nowPeriodActivity.getAwardId4().equals(awardId)) { turntableActivity.setAmount4(nowPeriodActivity.getAmount4() + 1); } else if (nowPeriodActivity.getAwardId5().equals(awardId)) { turntableActivity.setAmount5(nowPeriodActivity.getAmount5() + 1); } else if (nowPeriodActivity.getAwardId6().equals(awardId)) { turntableActivity.setAmount6(nowPeriodActivity.getAmount6() + 1); } } else { //替换操作 Integer oldAwardId = Integer.valueOf(hget); // 查询用户是否有 没有抽取的必中记录 BsTurntableNextAward record = turntableNextAwardMapper.queryDataByUserAndState(userId, 0); if (record != null) { record.setAwardId(awardId); record.setSysUser(sysUser.getUserName()); turntableNextAwardMapper.updateByPrimaryKeySelective(record); //修改之前设置的必中商品已抽取库存总量：extractAmount - 1 turntableAwardMapper.updateExtractAmountReduceOneByAwardId(oldAwardId); //修改必中商品的已抽取库存总量：extractAmount + 1 turntableAwardMapper.updateExtractAmountAddOneByAwardId(awardId); } //更新替换操作，原有商品总投放量减一 jedis.hincrBy(Rkey.BRANCH_AWARD_ACTIVE_STOCK, oldAwardId.toString(), -1); //更新替换操作，替换商品总投放量加一 jedis.hincrBy(Rkey.BRANCH_AWARD_ACTIVE_STOCK, awardId.toString(), 1); } jedis.hset(Rkey.TURNTALE_NEXT_AWARD, userId.toString(), awardId.toString()); //数据库 } else { throw new BusiException(E.CUSTOM_ERROR_MSG, "用户不存在"); } } finally { RedisPool.returnJedis(jedis); } }

抽取之后，代码如下：

public void updateTurntableNextAward(Integer userId, Integer awardId, HttpServletRequest request) { //验证奖品 BsTurntableAward award = turntableAwardMapper.selectByPrimaryKey(awardId); if (award == null) { throw new BusiException(E.INVALID_PARAMETER, "奖品不存在"); } if (award.getState() != 1) { throw new BusiException(E.INVALID_PARAMETER, "奖品已停售"); } Jedis jedis = RedisPool.getJedis(); SysUser sysUser = (SysUser) request.getSession().getAttribute(R.LOGIN_USER); try { if (jedis.hexists(Rkey.USER_INFO, userId.toString())) { String hget = jedis.hget(Rkey.TURNTALE_NEXT_AWARD, userId.toString()); if (StringUtils.isEmpty(hget)) { //第一次设置 BsTurntableNextAward record = new BsTurntableNextAward(); record.setAwardId(awardId); record.setState(0); record.setUserId(userId); record.setSysUser(sysUser.getUserName()); turntableNextAwardMapper.insert(record); //修改必中商品的已抽取库存总量：extractAmount + 1 turntableAwardMapper.updateExtractAmountAddOneByAwardId(awardId); //新增操作，redis 对应商品总投放量加一 jedis.hincrBy(Rkey.BRANCH_AWARD_ACTIVE_STOCK, awardId.toString(), 1); //操作数据库 商品对应投放库存加一 //下面这部分可以抽取为1个方法，选中这部分，按下快捷键 Ctrl + Alt + M，填写方法名称即可抽取 updateAmountAddOneWhenSettingBizhong(awardId); } else { //替换操作 Integer oldAwardId = Integer.valueOf(hget); // 查询用户是否有 没有抽取的必中记录 BsTurntableNextAward record = turntableNextAwardMapper.queryDataByUserAndState(userId, 0); if (record != null) { record.setAwardId(awardId); record.setSysUser(sysUser.getUserName()); turntableNextAwardMapper.updateByPrimaryKeySelective(record); //修改之前设置的必中商品已抽取库存总量：extractAmount - 1 turntableAwardMapper.updateExtractAmountReduceOneByAwardId(oldAwardId); //修改必中商品的已抽取库存总量：extractAmount + 1 turntableAwardMapper.updateExtractAmountAddOneByAwardId(awardId); } //更新替换操作，原有商品总投放量减一 jedis.hincrBy(Rkey.BRANCH_AWARD_ACTIVE_STOCK, oldAwardId.toString(), -1); //更新替换操作，替换商品总投放量加一 jedis.hincrBy(Rkey.BRANCH_AWARD_ACTIVE_STOCK, awardId.toString(), 1); } jedis.hset(Rkey.TURNTALE_NEXT_AWARD, userId.toString(), awardId.toString()); //数据库 } else { throw new BusiException(E.CUSTOM_ERROR_MSG, "用户不存在"); } } finally { RedisPool.returnJedis(jedis); } } // 操作数据库 设置必中 对应商品库存加一 private void updateAmountAddOneWhenSettingBizhong(Integer awardId) { Date now = new Date(); String formatDate = DateUtil.formatDate(now, "yyyy-MM-dd HH:mm"); BsTurntableActivity nowPeriodActivity = turntableActivityMapper.queryNowPeriodActivity(formatDate); String curActivityId = nowPeriodActivity.getId().toString(); BsTurntableActivity turntableActivity = new BsTurntableActivity(); turntableActivity.setId(curActivityId); if (nowPeriodActivity.getAwardId1().equals(awardId)) { turntableActivity.setAmount1(nowPeriodActivity.getAmount1() + 1); } else if (nowPeriodActivity.getAwardId2().equals(awardId)) { turntableActivity.setAmount2(nowPeriodActivity.getAmount2() + 1); } else if (nowPeriodActivity.getAwardId3().equals(awardId)) { turntableActivity.setAmount3(nowPeriodActivity.getAmount3() + 1); } else if (nowPeriodActivity.getAwardId4().equals(awardId)) { turntableActivity.setAmount4(nowPeriodActivity.getAmount4() + 1); } else if (nowPeriodActivity.getAwardId5().equals(awardId)) { turntableActivity.setAmount5(nowPeriodActivity.getAmount5() + 1); } else if (nowPeriodActivity.getAwardId6().equals(awardId)) { turntableActivity.setAmount6(nowPeriodActivity.getAmount6() + 1); } turntableActivityMapper.updateByPrimaryKeySelective(turntableActivity); }

ps:  
1.选中要提取的部分，按下快捷键 `Ctrl + Alt + M`，填写方法名称即可抽取  
2.有可能提取的时候，提取的参数不够(不满足我们的期望)，可以等提取结束后手动修改，加入需要的参数。