android中如何通过代码检测是否有root权限？

封装了一个类，代码如下：

1. public class ShellCommand {
3. private Boolean can_su;    
5. public SH sh;
6. public SH su;
8. public ShellCommand() {
9. sh = new SH("sh");
10. su = new SH("su");
11. }
13. public boolean canSU() {
14. return canSU(false);
15. }
17. public boolean canSU(boolean force_check) {
18. if (can_su == null || force_check) {
19. CommandResult r = su.runWaitFor("id");
20. StringBuilder out = new StringBuilder();
22. if (r.stdout != null)
23. out.append(r.stdout).append(" ; ");
24. if (r.stderr != null)
25. out.append(r.stderr);
27. can_su = r.success();
28. }
29. return can_su;
30. }
32. public SH suOrSH() {
33. return canSU() ? su : sh;
34. }
36. public class CommandResult {
37. public final String stdout;
38. public final String stderr;
39. public final Integer exit_value;
41. CommandResult(Integer exit_value_in, String stdout_in, String stderr_in)
42. {
43. exit_value = exit_value_in;
44. stdout = stdout_in;
45. stderr = stderr_in;
46. }
48. CommandResult(Integer exit_value_in) {
49. this(exit_value_in, null, null);
50. }
52. public boolean success() {
53. return exit_value != null && exit_value == 0;
54. }
55. }
57. public class SH {
58. private String SHELL = "sh";
60. public SH(String SHELL_in) {
61. SHELL = SHELL_in;
62. }
64. public Process run(String s) {
65. Process process = null;
66. try {
67. process = Runtime.getRuntime().exec(SHELL);
68. DataOutputStream toProcess = new DataOutputStream(process.getOutputStream());
69. toProcess.writeBytes("exec " + s + "\n");
70. toProcess.flush();
71. } catch(Exception e) {
72. process = null;
73. }
74. return process;
75. }
77. private String getStreamLines(InputStream is) {
78. String out = null;
79. StringBuffer buffer = null;
80. DataInputStream dis = new DataInputStream(is);
82. try {
83. if (dis.available() > 0) {
84. buffer = new StringBuffer(dis.readLine());
85. while(dis.available() > 0)
86. buffer.append("\n").append(dis.readLine());
87. }
88. dis.close();
89. } catch (Exception ex) {
90. }
91. if (buffer != null)
92. out = buffer.toString();
93. return out;
94. }
96. public CommandResult runWaitFor(String s) {
97. Process process = run(s);
98. Integer exit_value = null;
99. String stdout = null;
100. String stderr = null;
101. if (process != null) {
102. try {
103. exit_value = process.waitFor();
105. stdout = getStreamLines(process.getInputStream());
106. stderr = getStreamLines(process.getErrorStream());
108. } catch(InterruptedException e) {
109. } catch(NullPointerException e) {
110. }
111. }
112. return new CommandResult(exit_value, stdout, stderr);
113. }
114. }
115. }

通过return new ShellCommand().canSU()即可获得。

注意这个方法最好放在异步中做，因为不同的机器检查时间不同。

1、最直接的判断有无root ：判断是否有权限管理。如果已经root，则手机往往会有权限管理器，可用安装需要权限的软件。
2、只要随便写个具有“写入”权限的代码，在Android真机的系统目录里试试就知道，如果“写入”成功，说明具有root权限。

如果非要代码检测，下面代码可以试试

package com.pocketdigi;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import android.app.Activity;
import android.os.Bundle;

public class RootActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
DataInputStream stream;
if(isRooted()){
try {
stream = Terminal("ping -c 2 www.pocketdigi.com");
//其实ping并不需要root权限 ,这里是ping 2次后才停止，所以启动后需要一点时间才会有显示
//你可以自己换成需要root权限的命令试试
String temp;
while((temp=stream.readLine())!=null){
System.out.println(temp);
//循环输出返回值
}
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
public DataInputStream Terminal(String command) throws Exception
{
Process process = Runtime.getRuntime().exec("su");
//执行到这，Superuser会跳出来，选择是否允许获取最高权限
OutputStream outstream = process.getOutputStream();
DataOutputStream DOPS = new DataOutputStream(outstream);
InputStream instream = process.getInputStream();
DataInputStream DIPS = new DataInputStream(instream);
String temp = command + "\n";
//加回车
DOPS.writeBytes(temp);
//执行
DOPS.flush();
//刷新，确保都发送到outputstream
DOPS.writeBytes("exit\n");
//退出
DOPS.flush();
process.waitFor();
return DIPS;
}
public boolean isRooted() {
//检测是否ROOT过
DataInputStream stream;
boolean flag=false;
try {
stream = Terminal("ls /data/");
//目录哪都行，不一定要需要ROOT权限的
if(stream.readLine()!=null)flag=true;
//根据是否有返回来判断是否有root权限
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();

}

return flag;
}

}

使用代码倒真是没试过，不过可以依照linux特性去思考。linux系统下root权限可以使用su命令，android本身也是小型的linux系统，所以可以尝试下面代码试验下：`
public static boolean runRootCommand(String command) {

1. Process process = null;  
2. DataOutputStream os = null;  
3. try {  
4. process = Runtime.getRuntime().exec("su");  
5. os = new DataOutputStream(process.getOutputStream());  
6. os.writeBytes(command+"\n");  
7. os.writeBytes("exit\n");  
8. os.flush();  
9. process.waitFor();  
10. } catch (Exception e) {  
11. Log.d("*** DEBUG ***", "Unexpected error - Here is what I know: "+e.getMessage());  
12. return false;  
13. }  
14. finally {  
15. try {  
16. if (os != null) {  
17. os.close();  
18. }  
19. process.destroy();  
20. } catch (Exception e) {  
21. // nothing  
22. }  
23. }  
24. return true;  
25. }  

}
`
另外如果不使用代码检测，可以有一个方法，将android设备连接USB调试，待识别设备后输入adb shell,如果出现$表述无root权限，如果出现#则表示有root权限，希望对你有用。

public static boolean runRootCommand(String command) {

1. Process process = null;  
2. DataOutputStream os = null;  
3. try {  
4. process = Runtime.getRuntime().exec("su");  
5. os = new DataOutputStream(process.getOutputStream());  
6. os.writeBytes(command+"\n");  
7. os.writeBytes("exit\n");  
8. os.flush();  
9. process.waitFor();  
10. } catch (Exception e) {  
11. Log.d("*** DEBUG ***", "Unexpected error - Here is what I know: "+e.getMessage());  
12. return false;  
13. }  
14. finally {  
15. try {  
16. if (os != null) {  
17. os.close();  
18. }  
19. process.destroy();  
20. } catch (Exception e) {  
21. // nothing  
22. }  
23. }  
24. return true;  
25. }  

}