https://source.android.com/ 
/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware.camera2;

import android.annotation.IntDef;
import android.util.AndroidException;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;


CameraAccessException is thrown if a camera device could not be queried or opened by the CameraManager, or if the connection to an opened CameraDevice is no longer valid.


See Also:
/**
 * <p><code>CameraAccessException</code> is thrown if a camera device could not
 * be queried or opened by the {@link CameraManager}, or if the connection to an
 * opened {@link CameraDevice} is no longer valid.</p>
 *
 * @see CameraManager
 * @see CameraDevice
 */
public class CameraAccessException extends AndroidException {
    
The camera device is in use already.

/**
     * The camera device is in use already.
     */
    public static final int CAMERA_IN_USE = 4;

    
The system-wide limit for number of open cameras or camera resources has
been reached, and more camera devices cannot be opened or torch mode
cannot be turned on until previous instances are closed.

/**
     * The system-wide limit for number of open cameras or camera resources has
     * been reached, and more camera devices cannot be opened or torch mode
     * cannot be turned on until previous instances are closed.
     */
    public static final int MAX_CAMERAS_IN_USE = 5;

    
The camera is disabled due to a device policy, and cannot be opened.

See Also:
  • setCameraDisabled.setCameraDisabled(ComponentName, boolean)
/**
     * The camera is disabled due to a device policy, and cannot be opened.
     *
     * @see android.app.admin.DevicePolicyManager#setCameraDisabled(android.content.ComponentName, boolean)
     */
    public static final int CAMERA_DISABLED = 1;

    
The camera device is removable and has been disconnected from the Android device, or the camera id used with CameraManager.openCamera is no longer valid, or the camera service has shut down the connection due to a higher-priority access request for the camera device. 
/**
     * The camera device is removable and has been disconnected from the Android
     * device, or the camera id used with {@link android.hardware.camera2.CameraManager#openCamera}
     * is no longer valid, or the camera service has shut down the connection due to a
     * higher-priority access request for the camera device.
     */
    public static final int CAMERA_DISCONNECTED = 2;

    
The camera device is currently in the error state.

The camera has failed to open or has failed at a later time as a result of some non-user interaction. Refer to StateCallback.onError for the exact nature of the error.


No further calls to the camera will succeed. Clean up the camera with CameraDevice.close and try handling the error in order to successfully re-open the camera. 


/**
     * The camera device is currently in the error state.
     *
     * <p>The camera has failed to open or has failed at a later time
     * as a result of some non-user interaction. Refer to
     * {@link CameraDevice.StateCallback#onError} for the exact
     * nature of the error.</p>
     *
     * <p>No further calls to the camera will succeed. Clean up
     * the camera with {@link CameraDevice#close} and try
     * handling the error in order to successfully re-open the camera.
     * </p>
     *
     */
    public static final int CAMERA_ERROR = 3;

    
A deprecated HAL version is in use.

@hide
/**
     * A deprecated HAL version is in use.
     * @hide
     */
    public static final int CAMERA_DEPRECATED_HAL = 1000;

    
@hide
/** @hide */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(prefix = { "CAMERA_", "MAX_CAMERAS_IN_USE" }, value = {
            CAMERA_IN_USE,
            MAX_CAMERAS_IN_USE,
            CAMERA_DISABLED,
            CAMERA_DISCONNECTED,
            CAMERA_ERROR
    })
    public @interface AccessError {}

    // Make the eclipse warning about serializable exceptions go away
    private static final long serialVersionUID = 5630338637471475675L; // randomly generated

    private final int mReason;

    
The reason for the failure to access the camera.

See Also:
/**
     * The reason for the failure to access the camera.
     *
     * @see #CAMERA_DISABLED
     * @see #CAMERA_DISCONNECTED
     * @see #CAMERA_ERROR
     */
    @AccessError
    public final int getReason() {
        return mReason;
    }

    public CameraAccessException(@AccessError int problem) {
        super(getDefaultMessage(problem));
        mReason = problem;
    }

    public CameraAccessException(@AccessError int problem, String message) {
        super(getCombinedMessage(problem, message));
        mReason = problem;
    }

    public CameraAccessException(@AccessError int problem, String message, Throwable cause) {
        super(getCombinedMessage(problem, message), cause);
        mReason = problem;
    }

    public CameraAccessException(@AccessError int problem, Throwable cause) {
        super(getDefaultMessage(problem), cause);
        mReason = problem;
    }

    
@hide
/**
     * @hide
     */
    public static String getDefaultMessage(@AccessError int problem) {
        switch (problem) {
            case CAMERA_IN_USE:
                return "The camera device is in use already";
            case MAX_CAMERAS_IN_USE:
                return "The system-wide limit for number of open cameras has been reached, " +
                       "and more camera devices cannot be opened until previous instances " +
                       "are closed.";
            case CAMERA_DISCONNECTED:
                return "The camera device is removable and has been disconnected from the " +
                        "Android device, or the camera service has shut down the connection due " +
                        "to a higher-priority access request for the camera device.";
            case CAMERA_DISABLED:
                return "The camera is disabled due to a device policy, and cannot be opened.";
            case CAMERA_ERROR:
                return "The camera device is currently in the error state; " +
                       "no further calls to it will succeed.";
        }
        return null;
    }

    private static String getCombinedMessage(@AccessError int problem, String message) {
        String problemString = getProblemString(problem);
        return String.format("%s (%d): %s", problemString, problem, message);
    }

    private static String getProblemString(int problem) {
        String problemString;
        switch (problem) {
            case CAMERA_IN_USE:
                problemString = "CAMERA_IN_USE";
                break;
            case MAX_CAMERAS_IN_USE:
                problemString = "MAX_CAMERAS_IN_USE";
                break;
            case CAMERA_DISCONNECTED:
                problemString = "CAMERA_DISCONNECTED";
                break;
            case CAMERA_DISABLED:
                problemString = "CAMERA_DISABLED";
                break;
            case CAMERA_ERROR:
                problemString = "CAMERA_ERROR";
                break;
            case CAMERA_DEPRECATED_HAL:
                problemString = "CAMERA_DEPRECATED_HAL";
                break;
            default:
                problemString = "<UNKNOWN ERROR>";
        }
        return problemString;
    }

}