Blankj/AndroidUtilCode · error · UnsupportedOperationException

u can't instantiate me...

Error message

u can't instantiate me...

What it means

UriUtils is a final static-only utility for URI/resource-path conversions. Its private constructor throws UnsupportedOperationException to prevent instantiation. All public methods (res2Uri, etc.) are static.

Source

Thrown at lib/utilcode/src/main/java/com/blankj/utilcode/util/UriUtils.java:36

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Array;
import java.lang.reflect.Method;

import androidx.core.content.FileProvider;

/**
 * <pre>
 *     author: Blankj
 *     blog  : http://blankj.com
 *     time  : 2018/04/20
 *     desc  : utils about uri
 * </pre>
 */
public final class UriUtils {

    private UriUtils() {
        throw new UnsupportedOperationException("u can't instantiate me...");
    }

    /**
     * Resource to uri.
     * <p>res2Uri([res type]/[res name]) -> res2Uri(drawable/icon), res2Uri(raw/icon)</p>
     * <p>res2Uri([resource_id]) -> res2Uri(R.drawable.icon)</p>
     *
     * @param resPath The path of res.
     * @return uri
     */
    public static Uri res2Uri(String resPath) {
        return Uri.parse("android.resource://" + Utils.getApp().getPackageName() + "/" + resPath);
    }

    /**
     * File to uri.
     *
     * @param file The file.

View on GitHub (pinned to 7b4caf9e54)

Solutions

  1. Use static methods: UriUtils.res2Uri(resPath) instead of constructing the class.
  2. Provide a Gson InstanceCreator / Jackson mixin returning a sentinel to avoid constructor invocation.
  3. Use Mockito.mockStatic for mocking rather than constructing UriUtils.
  4. Keep the class final with a private constructor.

Example fix

// before
UriUtils uu = new UriUtils();

// after
Uri uri = UriUtils.res2Uri("drawable/icon");
Defensive patterns

Strategy: validation

Validate before calling

if (Modifier.isFinal(UriUtils.class.getModifiers())) {
  throw new IllegalStateException("UriUtils is static-only.");
}

Prevention

When it happens

Trigger: Reflective instantiation via UriUtils.class.getDeclaredConstructor().setAccessible(true).newInstance(), or transitively through Gson/Jackson deserialization, Mockito/PowerMock, Kotlin reflection, or a DI scan.

Common situations: JSON mapping a field to UriUtils; mock frameworks in tests; coverage probes; accidental construction after weakening access modifiers.

Related errors

AI-assisted analysis of Blankj/AndroidUtilCode@7b4caf9e54 (2026-08-14). Data as JSON: /api/errors/a83a985a12e8fc6f. Report an issue: GitHub.