blocks|key|130362|text|https://expressjs.com/en/guide/error-handling.html上有一个关于错误处理的示例应用程序/指南，但是应该可以修复您的代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|130363|//+Require+Dependencies
var+express+=+require('express');
var+app+=+express();

//+Middleware
app.use(app.router);+//+you+need+this+line+so+the+.get+etc.+routes+are+run+and+if+an+error+within,+then+the+error+is+parsed+to+the+next+middleware+(your+error+reporter)
app.use(function(err,+req,+res,+next)+{
++++if(!err)+return+next();+//+you+also+need+this+line
++++console.log("error!!!");
++++res.send("error!!!");
});

//+Routes
app.get('/',+function(request,+response)+{
++++throw+"some+exception";
++++response.send('Hello+World!');
});

//+Listen
app.listen(5000,+function()+{
++console.log("Listening+on+5000");
});|code-block|syntax|javascript|130364|entityMap|0|LINK|mutability|MUTABLE|url|https://expressjs.com/en/guide/error-handling.html^0|0|1E|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

An example app/guide on error handling is available at 
<a href="https://expressjs.com/en/guide/error-handling.html" rel="nofollow noreferrer">https://expressjs.com/en/guide/error-handling.html</a>
However should fix your code:

<pre><code>// Require Dependencies
var express = require('express');
var app = express();

// Middleware
app.use(app.router); // you need this line so the .get etc. routes are run and if an error within, then the error is parsed to the next middleware (your error reporter)
app.use(function(err, req, res, next) {
 if(!err) return next(); // you also need this line
 console.log("error!!!");
 res.send("error!!!");
});

// Routes
app.get('/', function(request, response) {
 throw "some exception";
 response.send('Hello World!');
});

// Listen
app.listen(5000, function() {
 console.log("Listening on 5000");
});
</code></pre>

blocks|key|130427|text|以下是一些小贴士：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|130428|1)您的代码无法正常工作，因为您的错误处理程序中间件在到达路由之前已运行，因此错误处理程序从未有机会将错误传递给它。这种风格被称为延续传递。将错误处理程序放在中间件堆栈的最后。|130429|2)当出现未处理的错误时，应关闭服务器。最好的方法是调用server.close()，其中server是执行var+server+=+http.createServer(app);的结果|offset|length|style|CODE|130430|这意味着，您应该这样做：|130431|var+server+=+http.createServer(app);

app.use(function(err,+req,+res,+next)+{
++console.log("error!!!");
++res.send("error!!!");
++server.close();
});|code-block|syntax|javascript|130432|您可能还应该让server.close()超时，以防它无法完成(毕竟您的应用程序处于未定义的状态)：|130433|var+server+=+http.createServer(app);

app.use(function(err,+req,+res,+next)+{
++console.log("error!!!");
++res.send("error!!!");

++server.close();

++setTimeout(function+()+{
++++process.exit(1);
++},+3*1000);
});|130434|我制作了一个库，它可以为您完成所有这些工作，并允许您定义自定义响应，包括专门的错误视图、要服务的静态文件等：|130435|https://github.com/ericelliott/express-error-handler|130436|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|S|E|1I|10|0|0|0|0|0|0|0|1G|0|0^^$0|@$1|2|3|4|5|6|7|15|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|16|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|17|8|@$F|18|G|19|H|I]|$F|1A|G|1B|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|1C|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|1D|8|@]|9|@]|A|$O|P]]|$1|Q|3|R|5|6|7|1E|8|@]|9|@]|A|$]]|$1|S|3|T|5|N|7|1F|8|@]|9|@]|A|$O|P]]|$1|U|3|V|5|6|7|1G|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1H|8|@]|9|@$F|1I|G|1J|1|1K]]|A|$]]|$1|Y|3|-4|5|6|7|1L|8|@]|9|@]|A|$]]]|Z|$10|$5|11|12|13|A|$14|X]]]]

A few tips:

1) Your code wasn't working because your error handler middleware was run before your route was reached, so the error handler never had a chance to have the error passed to it. This style is known as continuation passing. Put your error handler last in the middleware stack.

2) You should shut down the server when you have an unhandled error. The best way to do that is to call <code>server.close()</code>, where server is the result of doing <code>var server = http.createServer(app);</code>

Which means, you should do something like this:

<pre><code>var server = http.createServer(app);

app.use(function(err, req, res, next) {
 console.log("error!!!");
 res.send("error!!!");
 server.close();
});
</code></pre>

You should probably also time out the server.close(), in case it can't complete (your app is in an undefined state, after all):

<pre><code>var server = http.createServer(app);

app.use(function(err, req, res, next) {
 console.log("error!!!");
 res.send("error!!!");

 server.close();

 setTimeout(function () {
 process.exit(1);
 }, 3*1000);
});
</code></pre>

I made a library that does all this for you, and lets you define custom responses, including specialized error views, static files to serve, etc...:

<a href="https://github.com/ericelliott/express-error-handler" rel="nofollow">https://github.com/ericelliott/express-error-handler</a>

blocks|key|130479|text|我也有同样的问题，不知道哪里出了问题。问题是，如果您定义了express+errorHandler，那么您的自定义错误处理程序将永远不会被调用。如果您有下一段代码，只需删除它：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|130480|if+('development'+===+app.get('env'))+{
++app.use(express.errorHandler());
}|code-block|syntax|javascript|130481|对我很有效：)|130482|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I had the same problem and couldn't figure out what was wrong.
The thing is if you have the express errorHandler defined then your custom error handler is never being called.
If you have the next code, simply remove it:

<pre><code>if ('development' === app.get('env')) {
 app.use(express.errorHandler());
}
</code></pre>

Worked for me:)

blocks|key|348392|text|安装express+install+connect-domain，然后如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|348393|var+express+=+require("express"),++
++++connectDomain+=+require("connect-domain"),
++++app+=+express(),
++++errorHandler;|code-block|syntax|javascript|348394|//我们的错误处理程序|348395|app.use(connectDomain());++
++++errorHandler+=+function+(err,+req,+res,+next)+{++
++++++++res.send(500,+{
+++++++++++"status":+"error",
+++++++++++"message":+err.message
++++++++});
++++console.log(err);
};|348396|然后在设置端点时，在errorHandler+()的末尾添加use：|348397|app.get("/some/data",+function+(req,+res)+{++
++++//+...+do+some+stuff+...
++++res.send(200,+"Yay!+Happy+Success!");
}).use(errorHandler);|348398|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Installing express install connect-domain, then something like this:

<pre><code>var express = require("express"), 
 connectDomain = require("connect-domain"),
 app = express(),
 errorHandler;
</code></pre>

// Our error handler

<pre><code>app.use(connectDomain()); 
 errorHandler = function (err, req, res, next) { 
 res.send(500, {
 "status": "error",
 "message": err.message
 });
 console.log(err);
};
</code></pre>

Then when setting up your endpoints, tack errorHandler on the end in a use():

<pre><code>app.get("/some/data", function (req, res) { 
 // ... do some stuff ...
 res.send(200, "Yay! Happy Success!");
}).use(errorHandler);
</code></pre>

I'm trying to get error handling running with express but instead of seeing a response of "error!!!" like I expect I see "some exception" on the console and then the process is killed. Is this how error handing is supposed to be setup and if so is there another way to catch errors?

<pre><code>var express = require('express');
var app = express();

app.use(function(err, req, res, next) {
 console.log("error!!!");
 res.send("error!!!");
});

app.get('/', function(request, response) {
 throw "some exception";
 response.send('Hello World!');
});

app.listen(5000, function() {
 console.log("Listening on 5000");
});
</code></pre>

Express js error handling

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我正在尝试使用express运行错误处理，但没有看到响应“error！”就像我期望的那样，我在控制台上看到了“一些异常”，然后进程就被终止了。这是错误处理应该设置的方式吗?如果是这样，是否有其他方法来捕获错误？var express = require('express');var app = express();ap...

问Express js错误处理
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