angular proxy config json not redirected to spring

we may face this error, when we try to hit from angular UI to back end java(Spring etc.,). The problem is with angular proxy conf json file. 

The configuration (Sample )should be ,

{
  "/api": {
    "target": "http://url.com",
    "secure": false,

    "changeOrigin": true,
    "pathRewrite": {"^/api" : ""}
  }
}

Here, "changeOrigin": true, is not mandatory if you are running in local host. means, both Cline and server both are running in same machine. But if it is different host, then changeOrigin is must. However we should need this at final production. So better set now itself.