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/tech/aiops/3254.html