Android 通过应用程序来设置系统的日期和时间中的

import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.Calendar;

import android.os.SystemClock;

public class SystemDateTime {
	
	static final String TAG = "SystemDateTime"; 
	
	public static void setDateTime(int year, int month, int day, int hour, int minute) throws IOException, InterruptedException {

		requestPermission();

    	Calendar c = Calendar.getInstance();

        c.set(Calendar.YEAR, year);
        c.set(Calendar.MONTH, month-1);
        c.set(Calendar.DAY_OF_MONTH, day);
        c.set(Calendar.HOUR_OF_DAY, hour);
        c.set(Calendar.MINUTE, minute);
        
        
        long when = c.getTimeInMillis();

        if (when / 1000 < Integer.MAX_VALUE) {
            SystemClock.setCurrentTimeMillis(when);
        }

        long now = Calendar.getInstance().getTimeInMillis();
        //Log.d(TAG, "set tm="+when + ", now tm="+now);

        if(now - when > 1000)
        	throw new IOException("failed to set Date."); 
        
	}

	public static void setDate(int year, int month, int day) throws IOException, InterruptedException {

		requestPermission();

    	Calendar c = Calendar.getInstance();

        c.set(Calendar.YEAR, year);
        c.set(Calendar.MONTH, month);
        c.set(Calendar.DAY_OF_MONTH, day);
        long when = c.getTimeInMillis();

        if (when / 1000 < Integer.MAX_VALUE) {
            SystemClock.setCurrentTimeMillis(when);
        }

        long now = Calendar.getInstance().getTimeInMillis();
        //Log.d(TAG, "set tm="+when + ", now tm="+now);

        if(now - when > 1000)
        	throw new IOException("failed to set Date.");
	}

	public static void setTime(int hour, int minute) throws IOException, InterruptedException {
		
		requestPermission();

        Calendar c = Calendar.getInstance();

        c.set(Calendar.HOUR_OF_DAY, hour);
        c.set(Calendar.MINUTE, minute);
        long when = c.getTimeInMillis();

		if (when / 1000 < Integer.MAX_VALUE) {
			SystemClock.setCurrentTimeMillis(when);
		}

		long now = Calendar.getInstance().getTimeInMillis();
        //Log.d(TAG, "set tm="+when + ", now tm="+now);

        if(now - when > 1000)
        	throw new IOException("failed to set Time.");
	}
	
	static void requestPermission() throws InterruptedException, IOException {
		createSuProcess("chmod 666 /dev/alarm").waitFor();
	}
	
	static Process createSuProcess() throws IOException  {
		File rootUser = new File("/system/xbin/ru");
		if(rootUser.exists()) {
			return Runtime.getRuntime().exec(rootUser.getAbsolutePath());
		} else {
			return Runtime.getRuntime().exec("su");
		}
	}
	
	static Process createSuProcess(String cmd) throws IOException {

		DataOutputStream os = null;
		Process process = createSuProcess();

		try {
			os = new DataOutputStream(process.getOutputStream());
			os.writeBytes(cmd + "\n");
			os.writeBytes("exit $?\n");
		} finally {
			if(os != null) {
				try {
					os.close();
				} catch (IOException e) {
				}
			}
		}

		return process;
	}
}