java運轉shell劇本辦法示例

如今經由過程CommandHelper.execute辦法可以履行敕令，該類完成

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類應用了CommandResult對象輸入成果毛病信息。該類完成

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;
    }
}

如今看看挪用代碼的演示（main函數接收一個超時參數）：

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());
        }
    }

成果會創立一個testdir目次。
我測驗考試用這類辦法創立經由過程ssh登錄到長途機械，碰到兩個成績：
1）假如願望沒有人機對話方法，則須要應用敕令sshpass -p password ssh user@targetIP 'command'
2) 在NetBeans上直接運轉工程是不可的，由於權限不敷,須要在終端裡運轉java javaapplication3.Main
3) 許多敕令不克不及運轉，只要如pwd等敕令可以運轉，緣由還不清晰，最好改用Ganymed SSH-2庫或許其他相似Java庫，我會鄙人一篇文章中引見若何應用。