正在努力学习Javascript。如果这真的是我所缺少的基本薄,请原谅。
我正在尝试将
node-fetch
运行到错误的网址,并且我希望它应该被捕获并记录我的相应消息。但是,当我通过节点运行此文件时,它给了我未捕获的错误
const fetch = require('node-fetch');
fetch('http://api.icnd.com/jokes/random/10')
.then(response => {
response.json().then((data) => {
console.log(data)
});
}).
catch(error => {
console.log('There is some error');
});
(node:864) UnhandledPromiseRejectionWarning: FetchError: invalid json response body at http://api.icnd.com/jokes/random/10 reason: Unexpected token < in JSON at position 0
at /Users/raheel/code/js-tutorial/node_modules/node-fetch/lib/index.js:254:32
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:118:7)
(node:864) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)
(node:864) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
因为你没有抛出特定的错误供 catch 块捕获。
const fetch = require('node-fetch');
fetch('http://api.icnd.com/jokes/random/10/api/1')
.then(response => {
if (response.ok) {
response.json().then((data) => {
console.log(data);
});
} else {
throw 'There is something wrong';
}
}).
catch(error => {
console.log(error);
});
就是这部分没被抓住:
response.json()
因此为其附加一个捕获处理程序:
response.json().catch(...)
或者简单地返回它,以便它被其他处理程序捕获:
return response.json()
正确的解决方案是首先检查响应状态代码是否为 2xx,因为超出此范围的 HTTP 响应代码不会被视为 JavaScript 错误(因此不会被抛出)。
因此,在开始任何解析之前,您必须检查响应对象上的
ok
属性。
const fetch = require('node-fetch');
fetch('http://api.icnd.com/jokes/random/10')
.then(response => {
if (response.ok) {
return response.json();
} else {
console.error(response.status, response.statusText);
throw Error(`${response.status} - ${response.statusText}`);
}
})
.then((data) => {
console.log(data);
})
.catch(error => {
console.error('There is some error', error);
});
参考:https://dev.to/anchobies/when-that-s-not-so-fetch-error-handling-with-fetch-4cce
您可以像下面的代码一样使用 catch 处理获取错误
fetch("url").then(response=> response.json()).then(data=>{
res.render("index",{data:data});
}).catch(error=>{
//handle error here
});
reject(await response.text())
如果您确定它返回 JSON ,那么
reject(await response.json())