[Java][Android][Process] Process 创建+控制+分析 经验浅谈

Posted 2020-09-20 jhcelue

不管是android亦或者Java中或多或少须要调用底层的一些命令。运行一些參数；

此时我们须要用到Java的Process来创建一个子进程。之所以是子进程是由于此进程依赖于发起创建请求的进程，假设发起者被Kill那个子进程也将Kill。

对于Process相信使用过的朋友一定不会陌生，它具有例如以下特点：

1.创建简单 

2.控制难 

3.easy导致无法创建子进程 

4.假设是多线程那么非常有可能造成内存溢出

以上现象假设你仅仅是偶尔使用一次，创建一个进程也许你什么都没有感觉到，可是假设你使用了多线程，进行了大量的创建，以上问题你都会遇到。

相关：[Android] ProcessBuilder与Runtime.getRuntime().exec分别创建进程的差别，[Android] [Java] 分享 Process 运行命令行封装类

这两个星期一直在研究上面的问题，我要做的软件是在Android中进行TraceRoute，因为手机不可能全然Root所以不能採用JNI来发送ICMP请求的方式，终于仅仅能使用创建进程方式进行。详细实现思路是：使用PING命令来PING百度等地址，在PING命令中增加TTL，得到每一次的IP地址。当IP地址与目标IP地址符合时退出。而且还须要单独PING一次每一跳的延迟和丢包。

单线程：PING 百度 TTL=1 =》 得到IP，PING IP 得到延迟丢包。改变TTL，进行下一次PING。直到所得到的IP与目标（百度）一样时停止。

依照上面的思路一次须要创建两个子进程。一般到百度时TTL大约为12跳左右，所以就是2*12=24个子进程；假设是在单线程下简单明了，可是速度慢，整个过程大约须要1分钟左右。

多线程：同一时候发起3个线程进行3跳測试TTL=（1，2。3），測试完毕后測试下一批数据TTL=（4，5，6）。假设也是12跳的话。那么也是24个子进程，可是总体耗时将会为1/3.可见此时效率较高。

可是多线程须要考虑的是线程的同步问题，以及得到数据后的写入问题，这些赞不谈。仅仅谈进程问题。经过我的測试假如如今測试100个站点的TraceRoute数据，在上层控制一次測试4个站点，底层实现并发3个线程，此时在一定时间内将会同一时候存在3*4个进程。依照平均每一个站点12跳来算：12*2*100=240个子进程，须要的子线程为12*100=120个。

这个时候问题来了，假如如今程序子进程不正常了，遇到了一个一定的问题导致进程无法运行完毕。此时你的现象是：一个子进程卡住，随后创建的全部子进程都卡住。

假如最上层线程做了任务时间限制。那么到时间后将会尝试销毁，可是你会发现无法销毁，所持有的线程也不会销毁。

可是上层以为销毁掉了，然后继续进行下一批的数据測试。此时你的线程数量会逐渐添加，假设100任务下来你的线程也许会达到3*4*100=1200假设有前期没有这种情况那个就是一半：600个线程左右，假设后期还有任务将会继续添加可是却永远不会销毁。可是我们知道JVM的内存是有限的。所以此时将会出现内存溢出。

以上就是我遇到的问题，我最先改为了等待线程全然返回后再进行下一批数据測试。此时内存溢出是攻克了，可是任务却一直卡住在哪里了，永远也不走。

我就在想要解决这一的问题须要解决根本上的问题才行。经过研究我发如今程序创建了子进程后JVM将会创建一个子进程管理线程：“ProcessManager”：

正常情况下该线程状态为Native。可是假设创建大量子进程后有可能会出现此线程为Monitor状态，过一段时间后全部创建子进程的线程状态也将会变为Monitor状态，然后将一直死锁，后面创建线程也是继续死锁，无法继续。

通过查看ProcessManager源代码发现，当中启动了一个线程用于监听子进程状态，同一时候管理子进程，比方输出消息以及关闭子进程等操作，详细例如以下：

/**
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package java.lang;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.util.HashMap;
import java.util.Map;
import java.util.Arrays;
import java.util.logging.Logger;
import java.util.logging.Level;

/***
 * Manages child processes.
 *
 * <p>Harmony‘s native implementation (for comparison purposes):
 * http://tinyurl.com/3ytwuq
 */
final class ProcessManager {

    /***
     * constant communicated from native code indicating that a
     * child died, but it was unable to determine the status
     */
    private static final int WAIT_STATUS_UNKNOWN = -1;

    /***
     * constant communicated from native code indicating that there
     * are currently no children to wait for
     */
    private static final int WAIT_STATUS_NO_CHILDREN = -2;

    /***
     * constant communicated from native code indicating that a wait()
     * call returned -1 and set an undocumented (and hence unexpected) errno
     */
    private static final int WAIT_STATUS_STRANGE_ERRNO = -3;

    /***
     * Initializes native static state.
     */
    static native void staticInitialize();
    static {
        staticInitialize();
    }

    /***
     * Map from pid to Process. We keep weak references to the Process objects
     * and clean up the entries when no more external references are left. The
     * process objects themselves don‘t require much memory, but file
     * descriptors (associated with stdin/out/err in this case) can be
     * a scarce resource.
     */
    private final Map<Integer, ProcessReference> processReferences
            = new HashMap<Integer, ProcessReference>();

    /*** Keeps track of garbage-collected Processes. */
    private final ProcessReferenceQueue referenceQueue
            = new ProcessReferenceQueue();

    private ProcessManager() {
        // Spawn a thread to listen for signals from child processes.
        Thread processThread = new Thread(ProcessManager.class.getName()) {
            @Override
            public void run() {
                watchChildren();
            }
        };
        processThread.setDaemon(true);
        processThread.start();
    }

    /***
     * Kills the process with the given ID.
     *
     * @parm pid ID of process to kill
     */
    private static native void kill(int pid) throws IOException;

    /***
     * Cleans up after garbage collected processes. Requires the lock on the
     * map.
     */
    void cleanUp() {
        ProcessReference reference;
        while ((reference = referenceQueue.poll()) != null) {
            synchronized (processReferences) {
                processReferences.remove(reference.processId);
            }
        }
    }

    /***
     * Listens for signals from processes and calls back to
     * {@link #onExit(int,int)}.
     */
    native void watchChildren();

    /***
     * Called by {@link #watchChildren()} when a child process exits.
     *
     * @param pid ID of process that exited
     * @param exitValue value the process returned upon exit
     */
    void onExit(int pid, int exitValue) {
        ProcessReference processReference = null;

        synchronized (processReferences) {
            cleanUp();
            if (pid >= 0) {
                processReference = processReferences.remove(pid);
            } else if (exitValue == WAIT_STATUS_NO_CHILDREN) {
                if (processReferences.isEmpty()) {
                    /**
                     * There are no eligible children; wait for one to be
                     * added. The wait() will return due to the
                     * notifyAll() call below.
                     */
                    try {
                        processReferences.wait();
                    } catch (InterruptedException ex) {
                        // This should never happen.
                        throw new AssertionError("unexpected interrupt");
                    }
                } else {
                    /**
                     * A new child was spawned just before we entered
                     * the synchronized block. We can just fall through
                     * without doing anything special and land back in
                     * the native wait().
                     */
                }
            } else {
                // Something weird is happening; abort!
                throw new AssertionError("unexpected wait() behavior");
            }
        }

        if (processReference != null) {
            ProcessImpl process = processReference.get();
            if (process != null) {
                process.setExitValue(exitValue);
            }
        }
    }

    /***
     * Executes a native process. Fills in in, out, and err and returns the
     * new process ID upon success.
     */
    static native int exec(String[] command, String[] environment,
            String workingDirectory, FileDescriptor in, FileDescriptor out,
            FileDescriptor err, boolean redirectErrorStream) throws IOException;

    /***
     * Executes a process and returns an object representing it.
     */
    Process exec(String[] taintedCommand, String[] taintedEnvironment, File workingDirectory,
            boolean redirectErrorStream) throws IOException {
        // Make sure we throw the same exceptions as the RI.
        if (taintedCommand == null) {
            throw new NullPointerException();
        }
        if (taintedCommand.length == 0) {
            throw new IndexOutOfBoundsException();
        }

        // Handle security and safety by copying mutable inputs and checking them.
        String[] command = taintedCommand.clone();
        String[] environment = taintedEnvironment != null ? taintedEnvironment.clone() : null;
        SecurityManager securityManager = System.getSecurityManager();
        if (securityManager != null) {
            securityManager.checkExec(command[0]);
        }
        // Check we‘re not passing null Strings to the native exec.
        for (String arg : command) {
            if (arg == null) {
                throw new NullPointerException();
            }
        }
        // The environment is allowed to be null or empty, but no element may be null.
        if (environment != null) {
            for (String env : environment) {
                if (env == null) {
                    throw new NullPointerException();
                }
            }
        }

        FileDescriptor in = new FileDescriptor();
        FileDescriptor out = new FileDescriptor();
        FileDescriptor err = new FileDescriptor();

        String workingPath = (workingDirectory == null)
                ? null
                : workingDirectory.getPath();

        // Ensure onExit() doesn‘t access the process map before we add our
        // entry.
        synchronized (processReferences) {
            int pid;
            try {
                pid = exec(command, environment, workingPath, in, out, err, redirectErrorStream);
            } catch (IOException e) {
                IOException wrapper = new IOException("Error running exec()." 
                        + " Command: " + Arrays.toString(command)
                        + " Working Directory: " + workingDirectory
                        + " Environment: " + Arrays.toString(environment));
                wrapper.initCause(e);
                throw wrapper;
            }
            ProcessImpl process = new ProcessImpl(pid, in, out, err);
            ProcessReference processReference
                    = new ProcessReference(process, referenceQueue);
            processReferences.put(pid, processReference);

            /**
             * This will wake up the child monitor thread in case there
             * weren‘t previously any children to wait on.
             */
            processReferences.notifyAll();

            return process;
        }
    }

    static class ProcessImpl extends Process {

        /*** Process ID. */
        final int id;

        final InputStream errorStream;

        /*** Reads output from process. */
        final InputStream inputStream;

        /*** Sends output to process. */
        final OutputStream outputStream;

        /*** The process‘s exit value. */
        Integer exitValue = null;
        final Object exitValueMutex = new Object();

        ProcessImpl(int id, FileDescriptor in, FileDescriptor out,
                FileDescriptor err) {
            this.id = id;

            this.errorStream = new ProcessInputStream(err);
            this.inputStream = new ProcessInputStream(in);
            this.outputStream = new ProcessOutputStream(out);
        }

        public void destroy() {
            try {
                kill(this.id);
            } catch (IOException e) {
                Logger.getLogger(Runtime.class.getName()).log(Level.FINE,
                        "Failed to destroy process " + id + ".", e);
            }
        }

        public int exitValue() {
            synchronized (exitValueMutex) {
                if (exitValue == null) {
                    throw new IllegalThreadStateException(
                            "Process has not yet terminated.");
                }

                return exitValue;
            }
        }

        public InputStream getErrorStream() {
            return this.errorStream;
        }

        public InputStream getInputStream() {
            return this.inputStream;
        }

        public OutputStream getOutputStream() {
            return this.outputStream;
        }

        public int waitFor() throws InterruptedException {
            synchronized (exitValueMutex) {
                while (exitValue == null) {
                    exitValueMutex.wait();
                }
                return exitValue;
            }
        }

        void setExitValue(int exitValue) {
            synchronized (exitValueMutex) {
                this.exitValue = exitValue;
                exitValueMutex.notifyAll();
            }
        }

        @Override
        public String toString() {
            return "Process[id=" + id + "]";  
        }
    }

    static class ProcessReference extends WeakReference<ProcessImpl> {

        final int processId;

        public ProcessReference(ProcessImpl referent,
                ProcessReferenceQueue referenceQueue) {
            super(referent, referenceQueue);
            this.processId = referent.id;
        }
    }

    static class ProcessReferenceQueue extends ReferenceQueue<ProcessImpl> {

        @Override
        public ProcessReference poll() {
            // Why couldn‘t they get the generics right on ReferenceQueue?
 :(
            Object reference = super.poll();
            return (ProcessReference) reference;
        }
    }

    static final ProcessManager instance = new ProcessManager();

    /*** Gets the process manager. */
    static ProcessManager getInstance() {
        return instance;
    }

    /*** Automatically closes fd when collected. */
    private static class ProcessInputStream extends FileInputStream {

        private FileDescriptor fd;

        private ProcessInputStream(FileDescriptor fd) {
            super(fd);
            this.fd = fd;
        }

        @Override
        public void close() throws IOException {
            try {
                super.close();
            } finally {
                synchronized (this) {
                    if (fd != null && fd.valid()) {
                        try {
                            ProcessManager.close(fd);
                        } finally {
                            fd = null;
                        }
                    }
                }
            }
        }
    }

    /*** Automatically closes fd when collected. */
    private static class ProcessOutputStream extends FileOutputStream {

        private FileDescriptor fd;

        private ProcessOutputStream(FileDescriptor fd) {
            super(fd);
            this.fd = fd;
        }

        @Override
        public void close() throws IOException {
            try {
                super.close();
            } finally {
                synchronized (this) {
                    if (fd != null && fd.valid()) {
                        try {
                            ProcessManager.close(fd);
                        } finally {
                            fd = null;
                        }
                    }
                }
            }
        }
    }

    /*** Closes the given file descriptor. */
    private static native void close(FileDescriptor fd) throws IOException;
}

在当中有一个“native void watchChildren();”方法，此方法为线程主方法。详细实现能够看看JNI，在当中回调了方法：“void onExit(int pid, int exitValue);” 在方法中：

void onExit(int pid, int exitValue) {
        ProcessReference processReference = null;

        synchronized (processReferences) {
            cleanUp();
            if (pid >= 0) {
                processReference = processReferences.remove(pid);
            } else if (exitValue == WAIT_STATUS_NO_CHILDREN) {
                if (processReferences.isEmpty()) {
                    /**
                     * There are no eligible children; wait for one to be
                     * added. The wait() will return due to the
                     * notifyAll() call below.
                     */
                    try {
                        processReferences.wait();
                    } catch (InterruptedException ex) {
                        // This should never happen.
                        throw new AssertionError("unexpected interrupt");
                    }
                } else {
                    /**
                     * A new child was spawned just before we entered
                     * the synchronized block. We can just fall through
                     * without doing anything special and land back in
                     * the native wait().
                     */
                }
            } else {
                // Something weird is happening; abort!
                throw new AssertionError("unexpected wait() behavior");
            }
        }

        if (processReference != null) {
            ProcessImpl process = processReference.get();
            if (process != null) {
                process.setExitValue(exitValue);
            }
        }
    }

此方法作用是删除子进程队列中子进程同一时候通知子进程ProcessImpl已完毕。

可是在方法：“watchChildren（）”中假设出现System.in缓冲期满的情况那么进程将无法正常结束，它将一直等待缓冲区有空间存在。而缓冲区又是公共区间，假设一个出现等待那么兴许子进程也将所有等待。假设缓冲区无法清空。那么所有子进程将会所有死锁掉。

这就是导致子进程卡死的凶手。

知道问题关键点那么就会有人想办法解决，比如：

//...读取数据...

process.waitFor();

//....再次读取

这种方式看似非常好，可是你有没有想过有些数据无法及时返回，所以在waitfor()之前读取非常有可能没有数据导致进行waitfor()等待，这时我们能够看看源代码：

        public int waitFor() throws InterruptedException {
            synchronized (exitValueMutex) {
                while (exitValue == null) {
                    exitValueMutex.wait();
                }
                return exitValue;
            }
        }

        void setExitValue(int exitValue) {
            synchronized (exitValueMutex) {
                this.exitValue = exitValue;
                exitValueMutex.notifyAll();
            }
        }

这里能够看见假如没有退出值将会进行等待，直到通知发生，可是通知想要发生必需要靠“ProcessManager”线程来告诉你。

可是假如在等待过程中出现了大量的数据。导致System.IN满了，此时“ProcessManager”线程非常傻非常傻的进入了等待状态中，也将无法进行通知。而这边也就无法往下走。无法到达第二次读取，所以第二次读取就非常随机了，在大量数据下第二次读取基本上就是摆设。也就是说无法正常的运行，终于也将导致死锁。

解决的方法也非常easy。创建线程后我们能够创建一个线程来专门读取信息。直到“ProcessManager”线程通知结束的时候，才退出线程。

首先我们看看Process提供的“exitValue()”方法：

        public int exitValue() {
            synchronized (exitValueMutex) {
                if (exitValue == null) {
                    throw new IllegalThreadStateException(
                            "Process has not yet terminated.");
                }

                return exitValue;
            }
        }

可见在”exitValue“没有值时将会抛出异常而不会堵塞，所以能够得出：”exitValue()“与”waitfor()“都能够用于推断线程是否完毕。可是一个是堵塞的一个是不堵塞的方法。在线程中当然使用不堵塞的来完毕我们的工作：

    /**
     * 实例化一个ProcessModel
     *
     * @param process Process
     */
    private ProcessModel(Process process) {
        //init
        this.process = process;
        //get
        out = process.getOutputStream();
        in = process.getInputStream();
        err = process.getErrorStream();

        //in
        if (in != null) {
            isInReader = new InputStreamReader(in);
            bInReader = new BufferedReader(isInReader, BUFFER_LENGTH);
        }

        sbReader = new StringBuilder();

        //start read thread
        readThread();
    }

....................

    //读取结果
    private void read() {
        String str;
        //read In
        try {
            while ((str = bInReader.readLine()) != null) {
                sbReader.append(str);
                sbReader.append(BREAK_LINE);
            }
        } catch (Exception e) {
            e.printStackTrace();
            Logs.e(TAG, e.getMessage());
        }
    }

    /**
     * 启动线程进行异步读取结果
     */
    private void readThread() {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                //
                while (true) {
                    try {
                        process.exitValue();
                        //read last
                        read();
                        break;
                    } catch (IllegalThreadStateException e) {
                        read();
                    }
                    StaticFunction.sleepIgnoreInterrupt(300);
                }

                //read end
                int len;
                if (in != null) {
                    try {
                        while ((len = in.read(BUFFER)) > 0) {
                            Logs.d(TAG, String.valueOf(len));
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                        Logs.e(TAG, e.getMessage());
                    }
                }

                //close
                close();

                //done
                isDone = true;
            }
        });

        thread.setName("DroidTestAgent.Test.TestModel.ProcessModel:ReadThread");
        thread.setDaemon(true);
        thread.start();

    }

当创建进程后把进程丢进我建立的类中实例化为一个进程管理类。随后启动线程，线程运行中调用进程的”exitValue()“，假设异常就进入读取数据，直到不异常时再次读取一次最后数据，随后退出循环，退出后还读取了一次底层的数据（这个事实上能够不用要,纯属心理作用！）。最后写入完毕标记。

当中”StaticFunction.sleepIgnoreInterrupt(300);“是我写的静态方法用于休眠等待而已。也就是Sleep。仅仅只是增加了try catch。

当然光是读取IN流是不行的，还有Error流，这个时候就须要两个线程来完毕。一个也行。只是我为了简单採用了：ProcessBuilder类创建进程并重定向了错误流到IN流中。这样简化了操作。

而使用ProcessBuilder类须要注意的是同一个ProcessBuilder实例创建子进程的时候是须要进行线程同步操作的，由于假设并发操作将会导致进程參数错误等现象发生。所以建议加上线程相互排斥来实现。可是不建议反复创建ProcessBuilder实例。创建那么多实例，何不把全部子进程放在一个ProcessBuilder实例里边。降低内存消耗啊，手机伤不起啊。

有必要提出的是，当线程推断结束的时候，也就是退出值（exitvalue）有值得时候此时事实上在”ProcessManager“线程中已经杀掉了进程了。此时在进程中事实上没有此进程了。有的也就是运行后的数据流而已。所以正常结束情况下无需自己调用”destroy()“方法。调用后将会触发异常，说没有找到此进程。

        public void destroy() {
            try {
                kill(this.id);
            } catch (IOException e) {
                Logger.getLogger(Runtime.class.getName()).log(Level.FINE,
                        "Failed to destroy process " + id + ".", e);
            }
        }

最终讲完了。累啊；

最后给大家分享我自己弄得一个类（ProcessModel）。大家喜欢就直接拿去，假设有好的建议希望大家提出来：

import com.droidtestagent.journal.Logs;
import com.droidtestagent.util.StaticFunction;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Create By Qiujuer
 * 2014-08-05
 * <p/>
 * 运行命令行语句进程管理封装
 */
public class ProcessModel {
    private static final String TAG = "ProcessModel";
    //换行符
    private static final String BREAK_LINE;
    //错误缓冲
    private static final byte[] BUFFER;
    //缓冲区大小
    private static final int BUFFER_LENGTH;
    //创建进程时须要相互排斥进行
    private static final Lock lock = new ReentrantLock();
    //ProcessBuilder
    private static final ProcessBuilder prc;

    final private Process process;
    final private InputStream in;
    final private InputStream err;
    final private OutputStream out;
    final private StringBuilder sbReader;

    private BufferedReader bInReader = null;
    private InputStreamReader isInReader = null;
    private boolean isDone;


    /**
     * 静态变量初始化
     */
    static {
        BREAK_LINE = "\n";
        BUFFER_LENGTH = 128;
        BUFFER = new byte[BUFFER_LENGTH];

        prc = new ProcessBuilder();
    }


    /**
     * 实例化一个ProcessModel
     *
     * @param process Process
     */
    private ProcessModel(Process process) {
        //init
        this.process = process;
        //get
        out = process.getOutputStream();
        in = process.getInputStream();
        err = process.getErrorStream();

        //in
        if (in != null) {
            isInReader = new InputStreamReader(in);
            bInReader = new BufferedReader(isInReader, BUFFER_LENGTH);
        }

        sbReader = new StringBuilder();

        //start read thread
        readThread();
    }

    /**
     * 运行命令
     *
     * @param params 命令參数 eg: "/system/bin/ping", "-c", "4", "-s", "100","www.qiujuer.net"
     */
    public static ProcessModel create(String... params) {
        Process process = null;
        try {
            lock.lock();
            process = prc.command(params)
                    .redirectErrorStream(true)
                    .start();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //sleep 100
            StaticFunction.sleepIgnoreInterrupt(100);
            lock.unlock();
        }
        if (process == null)
            return null;
        return new ProcessModel(process);
    }

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

    /**
     * 获取进程的ID
     *
     * @param process 进程
     * @return id
     */
    public 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;
        }
    }

    //读取结果
    private void read() {
        String str;
        //read In
        try {
            while ((str = bInReader.readLine()) != null) {
                sbReader.append(str);
                sbReader.append(BREAK_LINE);
            }
        } catch (Exception e) {
            e.printStackTrace();
            Logs.e(TAG, e.getMessage());
        }
    }

    /**
     * 启动线程进行异步读取结果
     */
    private void readThread() {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                //while to end
                while (true) {
                    try {
                        process.exitValue();
                        //read last
                        read();
                        break;
                    } catch (IllegalThreadStateException e) {
                        read();
                    }
                    StaticFunction.sleepIgnoreInterrupt(300);
                }

                //read end
                int len;
                if (in != null) {
                    try {
                        while ((len = in.read(BUFFER)) > 0) {
                            Logs.d(TAG, String.valueOf(len));
                        }
                    } catch (IOException e) {
                        e.printStackTrace();
                        Logs.e(TAG, e.getMessage());
                    }
                }

                //close
                close();

                //done
                isDone = true;
            }
        });

        thread.setName("DroidTestAgent.Test.TestModel.ProcessModel:ReadThread");
        thread.setDaemon(true);
        thread.start();

    }

    /**
     * 获取运行结果
     *
     * @return 结果
     */
    public String getResult() {
        //waite process setValue
        try {
            process.waitFor();
        } catch (Exception e) {
            e.printStackTrace();
            Logs.e(TAG, e.getMessage());
        }

        //until startRead en
        while (true) {
            if (isDone)
                break;
            StaticFunction.sleepIgnoreInterrupt(100);
        }

        //return
        if (sbReader.length() == 0)
            return null;
        else
            return sbReader.toString();
    }

    /**
     * 关闭全部流
     */
    private void close() {
        //close out
        if (out != null) {
            try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        //err
        if (err != null) {
            try {
                err.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        //in
        if (in != null) {
            try {
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (isInReader != null) {
            try {
                isInReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (bInReader != null) {
            try {
                bInReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 销毁
     */
    public void destroy() {
        //process
        try {
            process.destroy();
        } catch (Exception ex) {
            kill(process);
        }
    }
}

想了想还是把代码托管到了GitHub上，方便以后分享其它的代码。
地址：Android Utils

很欢迎大家找出不足发表问题。