[Java][Android][Process] 分享 Process 执行命令行封装类

来源：互联网发布：辩证看待人工智能编辑：程序博客网时间：2024/05/17 16:03

在上一篇文章中提到，利用Java创建进程执行命令行语句创建过多后会出现无法创建进程的问题。

[Android] ProcessBuilder与Runtime.getRuntime().exec分别创建进程的区别

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     *               <pre> eg: "/system/bin/ping", "-c", "4", "-s", "100","www.qiujuer.net"</pre>     * @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。

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