Disable URL Encoding In Spring WebClient

In Spring, the WebClient class does not provide a direct way to disable URL encoding globally because encoding is generally required to ensure that URLs are correctly interpreted by servers. However, you can manage encoding at the point of specifying URI components when building the request. This allows you greater control over which parts of the URL should be encoded.

Option 1: Using DefaultUriBuilderFactory and setting its encoding mode

You can configure the WebClient to use a DefaultUriBuilderFactory with a specific encoding mode. The DefaultUriBuilderFactory.EncodingMode enum provides different options for controlling encoding.

Here’s how you can set it up:

import org.springframework.web.util.DefaultUriBuilderFactory;
import org.springframework.web.util.DefaultUriBuilderFactory.EncodingMode;
import org.springframework.web.reactive.function.client.WebClient;

public class WebClientConfig {

    public static WebClient createWebClient() {
        DefaultUriBuilderFactory factory = new DefaultUriBuilderFactory();
        factory.setEncodingMode(EncodingMode.NONE); // This will avoid encoding the URI

        return WebClient.builder()
                .uriBuilderFactory(factory)
                .build();
    }
}

Using EncodingMode.NONE will avoid encoding the URI components, but be cautious as this might lead to malformed URLs if the components contain invalid characters.

Option 2: Manually constructing URLs

If you want specific control over parts of the URL, you might choose to manually construct them and pass them directly to the WebClient:

import org.springframework.web.reactive.function.client.WebClient;

public class WebClientUsage {

    public void callService() {
        String baseUrl = "http://example.com";
        String unencodedPath = "/api/data";
        String queryParamKey = "param";
        String queryParamValue = "value1,value2"; // Example of a value that typically needs encoding

        WebClient webClient = WebClient.create(baseUrl);

        String response = webClient.get()
                .uri(uriBuilder -> uriBuilder
                        .path(unencodedPath)
                        .queryParam(queryParamKey, queryParamValue) // Manually handle encoding if needed
                        .build())
                .retrieve()
                .bodyToMono(String.class)
                .block();
    }
}

In this example, you can manually encode queryParamValue if required, or leave it unencoded based on your specific needs.

Best Practices and Considerations

1. Security: Be cautious when disabling encoding, as improper handling of URLs can lead to security vulnerabilities, such as URL injection attacks.
2. Functionality: Thoroughly test URLs generated without encoding to ensure they are interpreted correctly by the server and don’t break the application.
3. Compatibility: Consider the expectations and requirements of the server you’re communicating with when deciding on encoding strategies.

By using these approaches, you can control how WebClient handles URL encoding in your Spring application.