Android修改时间实现

一、需要root过系统

下面的代码实现需要系统root过的。

package com.example.util;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.Calendar;

import android.os.SystemClock;

public class SystemDateTime {

public static void setDateTime(long when)  throws IOException, InterruptedException {

requestPermission();

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

long now = Calendar.getInstance().getTimeInMillis();

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

}

public static void setDateTime(int year, int month, int day, int hour, int minute, int Sec) 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);
c.set(Calendar.SECOND, Sec);

long when = c.getTimeInMillis();

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

long now = Calendar.getInstance().getTimeInMillis();

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();

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();

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;
}

}

createSuProcess(“chmod 666 /dev/alarm”)是用系统root权限进程来修改/dev/alarm目录的读写属性。“666”是能赋予各个组读写权限。chmod是Linux下修改权限属性的命令。Runtime.getRuntime().exec(“su”);是提权为root以root身份来执行命令。Runtime.getRuntime().exec(rootUser.getAbsolutePath());是获取系统root用户的绝对地址来获得root权限。像这些os.writeBytes(cmd + “\n”);是用给系统下达相应的命令，cmd是用户给的命令。

二、需要系统签名

实现代码和上面的代码差不多，只是没有提权部分代码而已。

package com.example.util;
import java.io.IOException;
import java.util.Calendar;

import com.sanlian.ui.MainActivity;

import android.os.SystemClock;
import android.util.Log;

public class SystemDateTimeUId {

public static void setDateTime(long when) throws IOException, InterruptedException {

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

long now = Calendar.getInstance().getTimeInMillis();

if(now - when > 1000) {
MainActivity.setDateTime = false;
throw new IOException("failed to set Date.");
} else {
MainActivity.setDateTime = true;
}

}

public static void setDateTime(int year, int month, int day, int hour, int minute, int Sec) throws IOException, InterruptedException {

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);
c.set(Calendar.SECOND, Sec);

long when = c.getTimeInMillis();

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

long now = Calendar.getInstance().getTimeInMillis();

if(now - when > 1000) {
MainActivity.setDateTime = false;
throw new IOException("failed to set Date.");
} else {
MainActivity.setDateTime = true;
}

}

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

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();

if(now - when > 1000) {
MainActivity.setDateTime = false;
throw new IOException("failed to set Date.");
} else {
MainActivity.setDateTime = true;
}
}

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

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();

if(now - when > 1000) {
MainActivity.setDateTime = false;
throw new IOException("failed to set Date.");
} else {
MainActivity.setDateTime = true;
}
}

}

在AndroidManifest.xml里的头添加android:sharedUserId=”android.uid.system”像下面代码这样。这是将自己的程序加入到了系统的进程中，获得系统权限。

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example"
android:sharedUserId="android.uid.system"
android:versionCode="1"
android:versionName="1.0" >

打包后的代码还要添加对应系统的系统签名。我的系统签名文件是platform.pk8和platform.x509.pem。各系统需要各自的系统厂家提供系统签名。