Angular2中的REST服务异常处理
首先,我必须提到,我是Angular的初学者,我的示例代码有点结巴 我创建了一些简单的登录应用程序,它提示输入用户名和密码,调用登录REST服务(用Java编写),在登录成功时返回一些令牌,或者在登录失败时抛出异常 这是我的一些代码 登录组件:Angular2中的REST服务异常处理,rest,angular,exception-handling,observable,Rest,Angular,Exception Handling,Observable,首先,我必须提到,我是Angular的初学者,我的示例代码有点结巴 我创建了一些简单的登录应用程序,它提示输入用户名和密码,调用登录REST服务(用Java编写),在登录成功时返回一些令牌,或者在登录失败时抛出异常 这是我的一些代码 登录组件: import { Component, OnInit } from '@angular/core'; import { Router } from '@angular/router'; import { AuthenticationService }
import { Component, OnInit } from '@angular/core';
import { Router } from '@angular/router';
import { AuthenticationService } from '../_services/index';
@Component({
moduleId: module.id,
templateUrl: 'login.component.html'
})
export class LoginComponent implements OnInit {
model: any = {};
error = '';
constructor(
private router: Router,
private authenticationService: AuthenticationService) { }
ngOnInit() {
// reset login status
this.authenticationService.logout();
}
login() {
this.authenticationService.login(this.model.username, this.model.password)
.subscribe(result => {
if (result === true) {
this.router.navigate(['/']);
} else {
this.error = 'Login failed!';
}
},
err => {
this.error = 'Login failed!';
});
}
}
身份验证服务:
import { Injectable } from '@angular/core';
import { Http, Headers, RequestOptions, Response } from '@angular/http';
import { Observable } from 'rxjs';
import { CookieService } from 'angular2-cookie/core';
import { CookieOptionsArgs } from 'angular2-cookie/services/cookie-options-args.model';
import 'rxjs/add/operator/map';
@Injectable()
export class AuthenticationService {
public token: string;
constructor(private http: Http, private cookieService: CookieService) {
// set token if saved in cookie
this.token = cookieService.get('token');
}
login(username, password): Observable<boolean> {
return this.http.post('http://localhost:9081/MyApp/login?username=' + username + '&password=' + password, new RequestOptions({}))
.map((response: Response) => {
// login successful if there's a token in the response
let token = response.text();
if (token !== '-1') {
// set token
this.token = token;
// store token in cookie to keep user logged
let opts: CookieOptionsArgs = {
path: '/'
};
this.cookieService.put('token', token, opts);
// return true to indicate successful login
return true;
} else {
// return false to indicate failed login
return false;
}
});
}
logout(): void {
// clear token, remove cookie to log user out
this.token= null;
this.cookieService.remove('token');
}
}
从'@angular/core'导入{Injectable};
从'@angular/Http'导入{Http,Headers,RequestOptions,Response};
从“rxjs”导入{Observable};
从'angular2 cookie/core'导入{CookieService};
从“angular2 cookie/services/cookie options args.model”导入{CookieOptions args};
导入'rxjs/add/operator/map';
@可注射()
导出类身份验证服务{
公共令牌:字符串;
构造函数(私有http:http,私有cookieService:cookieService){
//设置保存在cookie中的令牌
this.token=cookieService.get('token');
}
登录(用户名、密码):可观察{
返回此.http.post('http://localhost:9081/MyApp/login?username='+username+'&password='+password,新请求选项({}))
.map((响应:响应)=>{
//如果响应中有令牌,则登录成功
让token=response.text();
如果(令牌!='-1'){
//设置令牌
this.token=token;
//将令牌存储在cookie中以保持用户日志记录
让选项:CookieOptions参数={
路径:'/'
};
this.cookieService.put('token',token,opts);
//返回true表示成功登录
返回true;
}否则{
//返回false表示登录失败
返回false;
}
});
}
注销():void{
//清除令牌,删除cookie以注销用户
this.token=null;
this.cookieService.remove('token');
}
}
一切正常。登录成功后,将返回令牌,并将我重定向到“主页”。否则,登录页面上会出现“登录失败”消息,并且不会发生重定向。困扰我的是,我不知道为什么登录失败:是因为用户名不存在,还是因为密码错误。处理REST服务引发的异常的正确方法是什么?我假设身份验证服务是正确的地方,但我不知道该怎么做。我试图从请求对象中提取一些信息,但若引发异常,则请求映射不会发生
谢谢你的帮助 您似乎在寻找捕获AuthenticationService中错误登录时发生的异常。如果是在.map之后添加.catch部分,如本主题:
我以这种方式实现了我的代码:
login(email: string, password: string): Observable<boolean> {
return new Observable(observer => {
var data = { email: email, password: password };
this.http.post(this.server_url + '/auth/authenticate', data).subscribe(x => {
var result = {
email: x.json().email,
token: x.json().token,
roles: x.json().roles.map(x => x.name)
}
localStorage.setItem(this._userKey, JSON.stringify(result));
observer.next(true);
observer.complete();
}, er => {
if (er.status == 401) {
observer.next(false);
observer.complete();
} else {
console.log(er);
observer.error(er);
observer.complete();
}
});
});
}
如果您在catch参数的Observable方面遇到错误,以下内容将有所帮助
login(email: string, password: string): Observable<boolean> {
return new Observable(observer => {
var data = { email: email, password: password };
this.http.post(this.server_url + '/auth/authenticate', data).subscribe(x => {
var result = {
email: x.json().email,
token: x.json().token,
roles: x.json().roles.map(x => x.name)
}
localStorage.setItem(this._userKey, JSON.stringify(result));
observer.next(true);
observer.complete();
}, er => {
if (er.status == 401) {
observer.next(false);
observer.complete();
} else {
console.log(er);
observer.error(er);
observer.complete();
}
});
});
}
login() {
this.loading = true;
this.authenticationService.login(this.model.username, this.model.password)
.subscribe(result => {
if (result == true) {
this.router.navigate(['/home']);
} else {
this.error = 'Username or password is incorrect';
this.loading = false;
}
}, err => {
this.error = 'Unexpected error occured.. please contact the administrator..';
this.loading = false;
});
}