idea 将代码块抽取为方法 快捷键
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。