Nodejs异步回调之异常处理实例分析

req.get('',function(req, res, next){
 var a = undefined.b; // 产生了一个exception
})
req.use(function(){req, res, next}{
 next(); //最终到 errorhandler中间件中处理
})

req.get('',function(req, res, next){
 redis.get('key', function(){
  var a = undefined.b; // 产生了一个exception
 })
})
req.use(function(){req, res, next}{
 next(); //最终到 errorhandler中间件中处理
})

process.on('uncaughtException', uncaughtExceptionHandler);

req.get('',function(req, res, next){
 try{
  redis.get('key', function(){
   var a = undefined.b; // 产生了一个exception
  })
 }catch(e){
  //并不会进到这里来
 }
})

function promiseFun() {
 return new Promise(function (resolve, reject) {
  redis.get('key', function(){
   resolve("Hello");
   // reject();
  })
 })
}
promiseFun().then().catch();

var getAsync1 = await async1();
async function async1() {
return new Promise(function (resolve, reject) {
  redis.get('key', function(){
   resolve("Hello");
   // reject();
  })
 });
}
console.log(getAsync1);

function promiseFun() {
 return new Promise(function (resolve, reject) {
  redis.get('key', function(){
   throw Error(); //依然捕获不到
  })
 })
}
promiseFun().then().catch();