在对Spring Boot应用程序使用AJAX请求时，在Chrome中出现CORS错误

Question

I am trying to run a Spring Boot application locally and I have some issues making an AJAX request back to the app. Chrome gives me the following error (which is actually from jquery):

Failed to load localhost:8080/api/input: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https.

I am trying to make a POST request that will be handled by the following method. This actually works with Postman.

@RequestMapping(value = "/api/input", method = RequestMethod.POST)
public @ResponseBody UserInputModel getUserInput(@RequestBody UserInputModel input)
{
    input.setMessage("bye");

    return input;
}

Here's the script that's making the request:

$(document).ready(function () {
$('#submitInput').click(function () {

    // Only send the message to the server if the user typed something
    var userMessage = {
        message: $('#userInput').val()
    };

    console.log(userMessage);

    if (userMessage.message) {
        console.log("Sending request");
        $.ajax({
            url: "localhost:8080/api/input",
            dataType: "json",
            contentType: "application/json; charset=UTF-8",
            data: JSON.stringify(userMessage),
            type: 'POST',
            success: function() {
                console.log("yay");
            },
            error: function(err) {
                console.log(err);
            }
        });
    } else {
        console.log("Empty input, no request sent");
    }
});

console.log("Loaded testScript.js");
});

So here's what's working. I have another controller that returns an html page (which also loads my script). This does work in Chrome, I get my page with the textbox and button and the script is indeed loaded. The problem is that the request from the script back to the app is not working.

Here's the pom.xml:

<?xml version="1.0" encoding="UTF-8"?>

http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4.0.0

<groupId>my.group</groupId>
<artifactId>appname</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>appname</name>
<description>Demo project for Spring Boot</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.8.RELEASE</version>
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <addResources>true</addResources>
            </configuration>
        </plugin>
    </plugins>
</build>

Answer 1

You can use JSONP: https://dev.socrata.com/docs/cors-and-jsonp.html

Or you can specify an explicit config in Spring boot:

@Configuration
public class RestConfig {
    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(true);
        config.addAllowedOrigin("*");
        config.addAllowedHeader("*");
        config.addAllowedMethod("OPTIONS");
        config.addAllowedMethod("GET");
        config.addAllowedMethod("POST");
        config.addAllowedMethod("PUT");
        config.addAllowedMethod("DELETE");
        source.registerCorsConfiguration("/**", config);
        return new CorsFilter(source);
    }
}

Check out: How to configure CORS in a Spring Boot + Spring Security application?