The WebUtil object provides utility methods for making HTTP requests and downloading files.
Importing WebUtil
import gg.essential.api.utils.WebUtil
import gg.essential.api.utils.WebUtil;
Fetching JSON
fetchJSON()
Fetch a JSON object from a URL and parse it into a JsonHolder.
val json = WebUtil.fetchJSON("https://api.example.com/data")
val value = json.optString("key")
JsonHolder json = WebUtil.fetchJSON("https://api.example.com/data");
String value = json.optString("key");
The URL to fetch JSON from
Returns a JsonHolder object which provides methods for safely accessing JSON data.
Fetching strings
fetchString()
Fetch the content of a web page as a string.
val content = WebUtil.fetchString("https://example.com/page")
if (content != "Failed to fetch") {
println("Page content: $content")
}
String content = WebUtil.fetchString("https://example.com/page");
if (!content.equals("Failed to fetch")) {
System.out.println("Page content: " + content);
}
The URL to fetch content from
Returns “Failed to fetch” if the request fails. Always check for this value before using the result.
Downloading files
downloadToFile()
Download a file from a URL and save it to disk.
import java.io.File
val destination = File("downloads/file.zip")
WebUtil.downloadToFile(
"https://example.com/file.zip",
destination,
"Mozilla/5.0 (MyMod)"
)
import java.io.File;
File destination = new File("downloads/file.zip");
WebUtil.downloadToFile(
"https://example.com/file.zip",
destination,
"Mozilla/5.0 (MyMod)"
);
The URL of the file to download
The destination file to save the downloaded content
The User-Agent header to use for the request
This method throws IOException if the download fails. Make sure to handle this exception.
Logging
LOG property
Enable or disable logging of HTTP requests.
// Enable logging for debugging
WebUtil.LOG = true
// Disable logging (default)
WebUtil.LOG = false
// Enable logging for debugging
WebUtil.LOG = true;
// Disable logging (default)
WebUtil.LOG = false;
Example: Fetching and parsing data
import gg.essential.api.utils.WebUtil
class UpdateChecker {
fun checkForUpdates(): String? {
try {
// Enable logging for debugging
WebUtil.LOG = true
// Fetch version info
val json = WebUtil.fetchJSON("https://api.mymod.com/version")
val latestVersion = json.optString("version")
val downloadUrl = json.optString("download_url")
return latestVersion
} catch (e: Exception) {
println("Failed to check for updates: ${e.message}")
return null
}
}
fun downloadUpdate(url: String, destination: File) {
try {
WebUtil.downloadToFile(url, destination, "MyMod/1.0")
println("Update downloaded successfully!")
} catch (e: IOException) {
println("Failed to download update: ${e.message}")
}
}
}
HTTP configuration
WebUtil uses the following default settings for HTTP connections:
- Read timeout: 15 seconds
- Connect timeout: 15 seconds
- Method: GET
- Caching: Enabled
- User-Agent: “Mozilla/4.76 (Essential)” (for fetchString/fetchJSON)
Error handling
All WebUtil methods handle errors internally and print stack traces to the console. For fetchString(), the method returns “Failed to fetch” on error instead of throwing an exception.
Always check the return value of fetchString() for the error sentinel value “Failed to fetch” before processing the result.
See also
Source: api/src/main/kotlin/gg/essential/api/utils/WebUtil.kt