Question

// getting cross-origin error in Web API 

    import { Injectable } from '@angular/core';
    import { Http, Headers, Response, RequestOptions } from '@angular/http';
    import { HttpClient, HttpHeaders } from '@angular/common/http'
    import { Observable } from 'rxjs/internal/Observable';
    import { FormGroup, FormBuilder, Validators } from '@angular/forms';
    import { map } from 'rxjs/operators';

    @Injectable()
    export class HomeService {

      constructor(private http: Http) {

      }
      getPrice() {

        const headers = new Headers();
        headers.set("Access-Control-Allow-Headers", "Origin, Content-Type, Accept");
        headers.set("Access-Control-Allow-Origin", "*");

        const options = new RequestOptions({ headers: headers });
        return this.http.get("http://localhost:8084/getPriceDetails", options).pipe(map(data => data))
      };
    }

// Java类文件

package com.xyz.Action;
import java.util.HashMap;
import java.util.Map;
import java.util.ResourceBundle;
import org.apache.struts.action.ActionForward;
import org.apache.struts.actions.LookupDispatchAction;
import java.util.ArrayList;

public class dataAction extends LookupDispatchAction {

    private ResourceBundle getResourceBundle() {
        ResourceBundle resourceBundle = null;

        return resourceBundle;
    }

    @Override
    protected Map getKeyMethodMap() {
        Map map = new HashMap();
        map.put("getPriceDetails", "getPriceDetails");
        return map;
    }

    public String getPriceDetails() {

       String str = "In Data Action";
        System.out.println("com.xyz.Action.dataAction.getPriceDetails()"+str);
        return str;
    }
}

我正在尝试从frontend（Angular）访问backend（java）。但是出现了跨源问题。所以我也添加了标头，但它不起作用。我想我必须更改后端代码。但没有到达何处。

Java代码（我刚刚创建了一个Java应用程序。我试图在前端和后端之间进行通信。）

Answer 1

如果您使用的是spring-boot，请使用以下配置。会起作用

@Bean
   public WebMvcConfigurer corsConfigurer() {
      return new WebMvcConfigurer() {
         @Override
         public void addCorsMappings( CorsRegistry registry ) {
            registry.addMapping( "/**" )
               .allowedOrigins( "*" )
               .allowedMethods( "*" )
               .allowedHeaders( "*" )
               .allowCredentials( true );
         }
      };
   }

，如果启用了弹簧安全性，则使用

@Override
protected void configure(HttpSecurity http) throws Exception { 
   http.cors().disable()
......
......
}

没有“访问控制允许来源”（交叉来源）

1 个答案: