Android 通过JNI实现守护进程(下)

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来源：LeBron_Six

链接：blog.csdn.net/yyh352091626/article/details/50542554

接上文

C/C++端关键的部分主要是以上这些，接下来就是Java端调用。

首先来看一下so库的加载类，以及C++函数的调用：

package com . yyh . fork ;

import java . io . DataInputStream ;

import java . io . DataOutputStream ;

import java . io . File ;

public class NativeRuntime {

private static NativeRuntime theInstance = null ;

private NativeRuntime () {

}

public static NativeRuntime getInstance () {

if ( theInstance == null )

theInstance = new NativeRuntime ();

return theInstance ;

}

/**

* RunExecutable 启动一个可自行的lib*.so文件

* @date 2016-1-18 下午8:22:28

* @param pacaageName

* @param filename

* @param alias 别名

* @param args 参数

* @return

*/

public String RunExecutable ( String pacaageName , String filename , String alias , String args ) {

String path = "/data/data/" + pacaageName ;

String cmd1 = path + "/lib/" + filename ;

String cmd2 = path + "/" + alias ;

String cmd2_a1 = path + "/" + alias + " " + args ;

String cmd3 = "chmod 777 " + cmd2 ;

String cmd4 = "dd if=" + cmd1 + " of=" + cmd2 ;

StringBuffer sb_result = new StringBuffer ();

if ( ! new File ( "/data/data/" + alias ). exists ()) {

RunLocalUserCommand ( pacaageName , cmd4 , sb_result ); // 拷贝lib/libtest.so到上一层目录,同时命名为test.

sb_result . append ( ";" );

}

RunLocalUserCommand ( pacaageName , cmd3 , sb_result ); // 改变test的属性,让其变为可执行

sb_result . append ( ";" );

RunLocalUserCommand ( pacaageName , cmd2_a1 , sb_result ); // 执行test程序.

sb_result . append ( ";" );

return sb_result . toString ();

}

/**

* 执行本地用户命令

* @date 2016-1-18 下午8:23:01

* @param pacaageName

* @param command

* @param sb_out_Result

* @return

*/

public boolean RunLocalUserCommand ( String pacaageName , String command , StringBuffer sb_out_Result ) {

Process process = null ;

try {

process = Runtime . getRuntime (). exec ( "sh" ); // 获得shell进程

DataInputStream inputStream = new DataInputStream ( process . getInputStream ());

DataOutputStream outputStream = new DataOutputStream ( process . getOutputStream ());

outputStream . writeBytes ( "cd /data/data/" + pacaageName + "\n" ); // 保证在command在自己的数据目录里执行,才有权限写文件到当前目录

outputStream . writeBytes ( command + " &\n" ); // 让程序在后台运行，前台马上返回

outputStream . writeBytes ( "exit\n" );

outputStream . flush ();

process . waitFor ();

byte [] buffer = new byte [ inputStream . available ()];

inputStream . read ( buffer );

String s = new String ( buffer );

if ( sb_out_Result != null )

sb_out_Result . append ( "CMD Result:\n" + s );

} catch ( Exception e ) {

if ( sb_out_Result != null )

sb_out_Result . append ( "Exception:" + e . getMessage ());

return false ;

}

return true ;

}