日期: 2017 年 10 月 21 日

發表於 程式分享

request JSON出現No ‘Access-Control-Allow-Origin’ header is present及OPTIONS 405 Method Not Allowed

發表於 由Grace撰寫

一、Tomcat8
由ionic2 撰寫 App POST 呼叫Tomcat8 Server程式時出現
No ‘Access-Control-Allow-Origin’ header is present，
雖於Chrome加上Allow-Control-Allow-Origin擴充功能，
1.PNG
仍出現錯誤訊息OPTIONS 405 Method Not Allowed，
經查原因
因為在跨域且嘗試添加一些特殊頭及自定義頭的情況下，
由於瀏覽器的安全機制 會加多一次OPTIONS預請求（詢問請求），
與跨域服務器協商可以設置的頭部信息，可以允許的HTTP協議等等信息。
即雖用POST，會先用OPTIONS詢問是否可使用OPTIONS，
故需在 OPTIONS 的 header 加上相關資訊，
解法可參考:https://tomcat.apache.org/tomcat-8.0-doc/config/filter.html#CORS_Filter/Introduction

<filter>
  <filter-name>CorsFilter</filter-name>
  <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
  <init-param>
    <param-name>cors.allowed.origins</param-name>
    <param-value>*</param-value>
  </init-param>
  <init-param>
    <param-name>cors.allowed.methods</param-name>
    <param-value>GET,POST,HEAD,OPTIONS,PUT</param-value>
  </init-param>
  <init-param>
    <param-name>cors.allowed.headers</param-name>
    <param-value>Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers</param-value>
  </init-param>
  <init-param>
    <param-name>cors.exposed.headers</param-name>
    <param-value>Access-Control-Allow-Origin,Access-Control-Allow-Credentials</param-value>
  </init-param>
  <init-param>
    <param-name>cors.support.credentials</param-name>
    <param-value>true</param-value>
  </init-param>
  <init-param>
    <param-name>cors.preflight.maxage</param-name>
    <param-value>10</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>CorsFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

二、IIS的解法
於Web.config設定


<system.webServer>
    ...
    <!-- No 'Access-Control-Allow-Origin' header is present on the requested resource.  -->
    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Origin" value="*" />
        <add name="Access-Control-Allow-Headers" value="Content-Type" />
        <add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" />
      </customHeaders>
    </httpProtocol>
  </system.webServer>