Process 执行命令行Java封装类详解手机开发

进行多次测试后发现是因为没有正常退出进程,以及完全读取掉流数据,和关闭流导致的问题。

在多次优化后,建立如下封装类:

ProcessModel.java

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.OutputStream; 
 
/** 
 * Create By Qiujuer 
 * 2014-07-26 
 * <p/> 
 * 执行命令行语句静态方法封装 
 */ 
public class ProcessModel { 
    //换行符 
    private static final String BREAK_LINE; 
    //执行退出命令 
    private static final byte[] COMMAND_EXIT; 
    //错误缓冲 
    private static byte[] BUFFER; 
 
    /** 
     * 静态变量初始化 
     */ 
    static { 
        BREAK_LINE = "/n"; 
        COMMAND_EXIT = "/nexit/n".getBytes(); 
        BUFFER = new byte[32]; 
    } 
 
 
    /** 
     * 执行命令 
     * 
     * @param params 命令参数 
     *               
 eg: "/system/bin/ping", "-c", "4", "-s", "100","www.qiujuer.net"

* @return 执行结果
*/
public static String execute(String... params) {
Process process = null;
StringBuilder sbReader = null;

BufferedReader bReader = null;
InputStreamReader isReader = null;

InputStream in = null;
InputStream err = null;
OutputStream out = null;

try {
process = new ProcessBuilder()
.command(params)
.start();
out = process.getOutputStream();
in = process.getInputStream();
err = process.getErrorStream();

out.write(COMMAND_EXIT);
out.flush();

process.waitFor();

isReader = new InputStreamReader(in);
bReader = new BufferedReader(isReader);

String s;
if ((s = bReader.readLine()) != null) {
sbReader = new StringBuilder();
sbReader.append(s);
sbReader.append(BREAK_LINE);
while ((s = bReader.readLine()) != null) {
sbReader.append(s);
sbReader.append(BREAK_LINE);
}
}

while ((err.read(BUFFER)) > 0) {
}
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
closeAllStream(out, err, in, isReader, bReader);

if (process != null) {
processDestroy(process);
process = null;
}
}

if (sbReader == null)
return null;
else
return sbReader.toString();
}

/**
* 关闭所有流
*
* @param out 输出流
* @param err 错误流
* @param in 输入流
* @param isReader 输入流封装
* @param bReader 输入流封装
*/
private static void closeAllStream(OutputStream out, InputStream err, InputStream in, InputStreamReader isReader, BufferedReader bReader) {
if (out != null)
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
if (err != null)
try {
err.close();
} catch (IOException e) {
e.printStackTrace();
}
if (in != null)
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
if (isReader != null)
try {
isReader.close();
} catch (IOException e) {
e.printStackTrace();
}
if (bReader != null)
try {
bReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}

/**
* 通过Android底层实现进程关闭
*
* @param process 进程
*/
private static void killProcess(Process process) {
int pid = getProcessId(process);
if (pid != 0) {
try {
//android kill process
android.os.Process.killProcess(pid);
} catch (Exception e) {
try {
process.destroy();
} catch (Exception ex) {
}
}
}
}

/**
* 获取进程的ID
*
* @param process 进程
* @return
*/
private static int getProcessId(Process process) {
String str = process.toString();
try {
int i = str.indexOf("=") + 1;
int j = str.indexOf("]");
str = str.substring(i, j);
return Integer.parseInt(str);
} catch (Exception e) {
return 0;
}
}

/**
* 销毁进程
*
* @param process 进程
*/
private static void processDestroy(Process process) {
if (process != null) {
try {
//判断是否正常退出
if (process.exitValue() != 0) {
killProcess(process);
}
} catch (IllegalThreadStateException e) {
killProcess(process);
}
}
}
}

在进行批量压力测试到达125643个线程的时候都没有出现此问题;特此分享给大家。

原创文章,作者:奋斗,如若转载,请注明出处:https://blog.ytso.com/3254.html

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