在程序中总会看到或者碰到很多根据key判断要执行的方法代码等等;
if(StringUtils.equals(key,"1")){
//逻辑1
} else if (StringUtils.equals(key,"2")){
//逻辑2
}
//...类型越多代码越繁多
switch (key){
case "1":
//逻辑1
break;
case "2":
//逻辑2
break;
/*
...
*/
default:
//默认处理
}
直接上代码:
@Controller
@RequestMapping("/dc/spring/mvc/ifElse")
public class OptimizationIfElseController {
/*
这里多入参可以考虑放到一个实体里面,使用Function
如果因业务原因必须多入参两个入参使用BiFunction
再多入参考虑柯里化方式Function,String>>
map.put("1",key->(instuCde,param)-> interface(key,instuCde,param));
*/
Map<String, BiFunction<String,Map<String, Object>,String>> map = new HashMap<>();
@RequestMapping(value = "/getIfElse/{code}", produces = "text/plain;charset=UTF-8")
public @ResponseBody String getIfElse(@PathVariable("code") String code) {
Map< String,Object> map = new HashMap<>();
map.put("Test1","TestValue");
return getReturn(code,"Dc",map);
}
/**
* map初始化 构造函数 > @Autowired > @PostConstruct
*/
@PostConstruct
public void mapInit(){
map.put("1",(instuCde,param)-> new OptimizationIfElse1ServiceImpl().testReturn(instuCde,param));
map.put("2",(instuCde,param)-> new OptimizationIfElse2ServiceImpl().testReturn(instuCde,param));
map.put("3",(instuCde,param)-> new OptimizationIfElse3ServiceImpl().testReturn(instuCde,param));
}
/**
* 执行程序
* @param className
* @param instuCde
* @param param
* @return
*/
private String getReturn(String className,String instuCde, Map<String, Object> param){
try {
BiFunction<String,Map<String, Object>,String> function = map.get(className);
if (Optional.ofNullable(function).isPresent()){
return function.apply(instuCde,param);
}
return "非正常业务逻辑!";
} catch (Exception e) {
return "业务异常!";
}
}
}
OptimizationIfElse1ServiceImpl ,OptimizationIfElse2ServiceImpl ,OptimizationIfElse3ServiceImpl 代码差不多只是为了测试,不再全部上了
@Service
public class OptimizationIfElse1ServiceImpl implements OptimizationIfElseService {
@Override
public String testReturn(String instuCde, Map<String, Object> param) {
return StrUtil.format("测试类1【{}】{}",instuCde, JSONObject.toJSONString(param));
}
}
执行结果
Java8的这种方式看着比较优雅,比策略模式看上去更简易,而且阅读起来,各种key要执行的方法在初始化的时候看起来一目了然,更容易理解。
共勉!