技術標籤：java

1.前端和後端傳參問題

1.接收Request Payload引數

1）方法2

前端若傳遞Request Payload引數，後端只能用實體類接收，並且要加上註解@RequestBody

2）方法2

 public ResTool account(HttpServletRequest  request,String userName, String password) {
        ServletInputStream is;
        try {
            is = request.getInputStream();
            int
 
 nRead = 1;
            int nTotalRead = 0;
            byte[] bytes = new byte[10240];
            while (nRead > 0) {
                nRead = is.read(bytes, nTotalRead, bytes.length - nTotalRead);
                if (nRead > 0) {
                    nTotalRead = nTotalRead + nRead;
                }
 

            }
            // 此處可以接收
            String str = new String(bytes, 0, nTotalRead, "utf-8");
            return ResTool.build();

        } catch (Exception e) {
            e.printStackTrace();
        }
        return ResTool.build();
    }

2.跨域解決辦法

關於CORS機制的詳細解釋這裡就不多做介紹了，相關的文件資源也很多，推薦檢視MDN上“

如下是nginx的配置片段，已經加好了相應的頭部：原因在於此介面的返回碼是400，而按照nginx官方文件針對add_header指令的說明，上面的配置，“add_header”指令預設只會給2xx和3xx開頭的部分http返回碼加上頭部，除此返回碼之外的其他響應是不會加上對應頭部的。

	location / {
            #proxy_pass http://127.0.0.1:9090/;
			proxy_pass http://127.0.0.1:8885/;
        //把OPTIONS的請求轉成2xx
		if ($request_method = 'OPTIONS') {
        return 204;
    }
            add_header "Access-Control-Allow-Origin" "*" always;
			add_header "Access-Control-Allow-Credentials" "true" always;
            add_header "Access-Control-Allow-Methods" "GET,POST,HEAD,PUT,DELETE,OPTIONS" always;
			add_header "Access-Control-Allow-Headers" "access-control-allow-origin, authority, content-type, version-info, X-Requested-With" always;
            proxy_set_header Host $host:$server_port;  
            proxy_set_header X-Real-IP $remote_addr;  
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;  
            proxy_set_header X-Request-Proxy-key proxyWS;
            proxy_connect_timeout 100;
            proxy_send_timeout 100;
            proxy_read_timeout 100;
        }