my favorite code for Android projects.

RutimeInit.java

/* RuntimeInit.java
 * My favorite initialization code for Android applications.
 *
 * Copyright (C) 2011 TAKUMAKei
 *
 * 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 com.blogspot.takumakei.gist;

import java.io.PrintStream;
import android.util.Log;

/**
 * The class for runtime initialization.
 *
 * <code>
 * class YourActivity extends Activity {
 *     static {
 *         RuntimeInit.setOut(android.util.Log.INFO, "Kei");
 *         RuntimeInit.setErr(android.util.Log.ERROR, "Kei");
 *     }
 * }
 * </code>
 */
public class RuntimeInit {
    /**
     * Redirect 'System.out' to android.util.Log with any priority and tag you want.
     *
     * @param priority from {@link android.util.Log}
     * @param tag to log
     */
    public static void setOut(int priority, String tag) {
        try {
            System.setOut(getAndroidPrintStream(priority, tag));
        } catch (Exception e) {
            Log.e(tag, "RuntimeInit.setOut", e);
        }
    }

    /**
     * Redirect 'System.err' to android.util.Log with any priority and tag you want.
     *
     * @param priority from {@link android.util.Log}
     * @param tag to log
     */
    public static void setErr(int priority, String tag) {
        try {
            System.setErr(getAndroidPrintStream(priority, tag));
        } catch (Exception e) {
            Log.e(tag, "RuntimeInit.setErr", e);
        }
    }

    /**
     * Create a new logging print stream.
     *
     * @param priority from {@link android.util.Log}
     * @param tag to log
     * @return A print stream which logs output line by line.
     * @throws Exception thrown when the com.android.internal.os.AndroidPrintStream was not found.
     */
    public static PrintStream getAndroidPrintStream(int priority, String tag) throws Exception {
        return (PrintStream) (Class
                              .forName("com.android.internal.os.AndroidPrintStream")
                              .getConstructor(int.class, String.class)
                              .newInstance(priority, tag));
    }
}