java运行shell脚本方法示例

现在通过commandhelper.execute方法可以执行命令，该类实现

package javaapplication3;
import java.io.bufferedreader;
import java.io.ioexception;
import java.io.inputstreamreader;
/**
 *
 * @author chenshu
 */
public class commandhelper {
    //default time out, in millseconds
    public static int default_timeout;
    public static final int default_interval = 1000;
    public static long start;
    public static commandresult exec(string command) throws ioexception, interruptedexception {
        process process = runtime.getruntime().exec(command);
        commandresult commandresult = wait(process);
        if (process != null) {
process.destroy();
        }
        return commandresult;
    }
    private static boolean isovertime() {
        return system.currenttimemillis() - start >= default_timeout;
    }
    private static commandresult wait(process process) throws interruptedexception, ioexception {
        bufferedreader errorstreamreader = null;
        bufferedreader inputstreamreader = null;
        try {
errorstreamreader = new bufferedreader(new inputstreamreader(process.geterrorstream()));
inputstreamreader = new bufferedreader(new inputstreamreader(process.getinputstream()));
//timeout control
start = system.currenttimemillis();
boolean isfinished = false;
for (;;) {
if (isovertime()) {
commandresult result = new commandresult();
result.setexitvalue(commandresult.exit_value_timeout);
result.setoutput("command process timeout");
return result;
}
if (isfinished) {
commandresult result = new commandresult();
result.setexitvalue(process.waitfor());
//parse error info
if (errorstreamreader.ready()) {
stringbuilder buffer = new stringbuilder();
string line;
while ((line = errorstreamreader.readline()) != null) {
buffer.append(line);
}
result.seterror(buffer.tostring());
}
//parse info
if (inputstreamreader.ready()) {
stringbuilder buffer = new stringbuilder();
string line;
while ((line = inputstreamreader.readline()) != null) {
buffer.append(line);
}
result.setoutput(buffer.tostring());
}
return result;
}
try {
isfinished = true;
process.exitvalue();
} catch (illegalthreadstateexception e) {
// process hasn't finished yet
isfinished = false;
thread.sleep(default_interval);
}
}
        } finally {
if (errorstreamreader != null) {
try {
errorstreamreader.close();
} catch (ioexception e) {
}
}
if (inputstreamreader != null) {
try {
inputstreamreader.close();
} catch (ioexception e) {
}
}
        }
    }
}

commandhelper类使用了commandresult对象输出结果错误信息。该类实现

package javaapplication3;
/**
 *
 * @author chenshu
 */
public class commandresult {
    public static final int exit_value_timeout=-1;
    private string output;
    void setoutput(string error) {
        output=error;
    }
    string getoutput(){
        return output;
    }
    int exitvalue;
    void setexitvalue(int value) {
        exitvalue=value;
    }
    int getexitvalue(){
        return exitvalue;
    }
    private string error;
    /**
     * @return the error
     */
    public string geterror() {
        return error;
    }
    /**
     * @param error the error to set
     */
    public void seterror(string error) {
        this.error = error;
    }
}

现在看看调用代码的演示（main函数接受一个超时参数）：

public static void main(string[] args) {
        try {
int timeout = integer.parseint(args[0]);
commandhelper.default_timeout = timeout;
commandresult result = commandhelper.exec("mkdir testdir");
if (result != null) {
system.out.println("output:" + result.getoutput());
system.out.println("error:" + result.geterror());
}
        } catch (ioexception ex) {
system.out.println("ioexception:" + ex.getlocalizedmessage());
        } catch (interruptedexception ex) {
system.out.println("interruptedexception:" + ex.getlocalizedmessage());
        }
    }

结果会创建一个testdir目录。
我尝试用这种方法创建通过ssh登录到远程机器，遇到两个问题：
1）如果希望没有人机对话方式，则需要使用命令sshpass -p password ssh user@targetip 'command'
2) 在netbeans上直接运行工程是不行的，因为权限不够,需要在终端里运行java javaapplication3.main
3) 很多命令不能运行，只有如pwd等命令可以运行，原因还不清楚，最好改用ganymed ssh-2库或者其他类似java库，我会在下一篇文章中介绍如何使用。