从Java程序运行grep

2019-06-29 22:49:20 阅读：273 来源： 互联网

标签：java linux grep process processbuilder

我花了3天时间在谷歌上没有太多运气如何从Java中运行grep进程.

我有以下代码来运行grep进程,但是,我只获得响应的第一行.

package com.example.parser;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) {
        try {
            Process process = new ProcessBuilder("grep", "-rni", "\"public static void main(\"", "/home/user/dev/java/").start();

            BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));

            String line = "";
            while((line = br.readLine()) != null) {
                System.out.println(line);
            }

            System.out.println("Exit Code: " + process.exitValue());

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

我只收到以下回复：

Binary file /home/user/dev/java/Parser/parser/bin/com/example/parser/Main.class matches
Exit Code: 0

当我得到以下回复时：

Binary file /home/user/dev/java/Parser/parser/com/example/parser/Main.class matches
/home/user/dev/java/Parser/parser/src/com/example/parser/Main.java:10:  public static void main(String[] args) {
/home/user/dev/java/Parser/parser/src/com/example/parser/Main.java:12:          Process process = new ProcessBuilder("grep", "-rni", "\"public static void main(\"", "/home/user/dev/java/Parser/parser").start();
Exit Code: 0

我想知道为什么我只得到第一个发现的输出？是grep分叉几个进程来运行搜索,我只是在第一个处理？

我也试过从线程运行进程：

package com.example.parser;

public class Main {

    public static void main(String[] args) {
        try {
            Analyzer analyzer = new Analyzer();
            analyzer.start();
            analyzer.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}


package com.example.parser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Analyzer extends Thread {

    public Analyzer() {
    }

    @Override
    public void run() {
        try {
            Process process = new ProcessBuilder("grep", "-rni", "\"public static void main(\"", "/home/user/dev/java/Parser/parser").start();
            process.waitFor();
            BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));

            String line = "";
            while((line = br.readLine()) != null) {
                System.out.println(line);
            }

            System.out.println("Exit Code: " + process.exitValue());

        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

以及以下内容：

package com.example.parser;

import java.io.IOException;

public class Main {

    public static void main(String[] args) {
        try {
            Process process = new ProcessBuilder("grep", "-rni", "\"public static void main(\"", "/home/user/dev/java/Parser/parser").start();
            process.waitFor();

            Analyzer analyzer_is = new Analyzer(process.getInputStream());
            Analyzer analyzer_es = new Analyzer(process.getErrorStream());

            analyzer_is.start();
            analyzer_es.start();

            analyzer_is.join();
            analyzer_es.join();

            System.out.println("Exit Code: " + process.exitValue());

        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}

package com.example.parser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class Analyzer extends Thread {

    InputStream is = null;

    public Analyzer(InputStream is) {
        this.is = is;
    }

    @Override
    public void run() {
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(this.is));

            String line = "";
            while((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

如下文所述：http://www.javaworld.com/jw-12-2000/jw-1229-traps.html

解决方法:

我能够通过启动带-c标志的shell来解决问题.以下代码执行我最初的预期：

package com.example.parser;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class Main {

    public static void main(String[] args) {
        try {
            List<String> commands = new ArrayList<String>();
            commands.add("/bin/sh");
            commands.add("-c");
            commands.add("grep -rni --include \"*.java\" \"public static void main(\" /home/user/dev/java/Parser/parser");

            Process process = new ProcessBuilder(commands).start();
            Analyzer analyzer_is = new Analyzer(process.getInputStream());
            Analyzer analyzer_es = new Analyzer(process.getErrorStream());

            analyzer_is.start();
            analyzer_es.start();

            process.waitFor();

            analyzer_is.join();
            analyzer_es.join();

            System.out.println("Exit Code: " + process.exitValue());

        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}


package com.example.parser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class Analyzer extends Thread {

    InputStream is = null;

    public Analyzer(InputStream is) {
        this.is = is;
    }

    @Override
    public void run() {
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(this.is));

            String line = "";
            while((line = br.readLine()) != null) {
                  System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

标签：java,linux,grep,process,processbuilder
来源： https://codeday.me/bug/20190629/1330571.html

本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享；
2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关；
3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关；
4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除；
5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。

ICode9

从Java程序运行grep