Java运行命令行并获取返回值（转）
本文转自：http://blog.csdn.net/chenzhanhai/article/details/7621655
?
方法一
//Process p = Runtime.getRuntime().exec("ping 127.0.0.1 -t");
??Process p = Runtime.getRuntime().exec("javac");
? InputStream is = p.getInputStream();
? BufferedReader reader = new BufferedReader(new InputStreamReader(is));
? String line;
? while((line = reader.readLine())!= null){
?? System.out.println(line);
? }
? p.waitFor();
? is.close();
? reader.close();
? p.destroy();
?}
方法二
package com.cmd;
import java.lang.*;
import java.io.*;
public class Process {
public static void main(String[] args) {
java.lang.Process process = null;
try {
process = Runtime.getRuntime().exec("net user");
ByteArrayOutputStream resultOutStream = new ByteArrayOutputStream();
InputStream errorInStream = new BufferedInputStream(process.getErrorStream());
InputStream processInStream = new BufferedInputStream(process.getInputStream());
int num = 0;
byte[] bs = new byte[1024];
while((num=errorInStream.read(bs))!=-1){
resultOutStream.write(bs,0,num);
}
while((num=processInStream.read(bs))!=-1){
resultOutStream.write(bs,0,num);
}
String result=new String(resultOutStream.toByteArray());
System.out.println(result);
errorInStream.close(); errorInStream=null;
processInStream.close(); processInStream=null;
resultOutStream.close(); resultOutStream=null;
} catch (IOException e) {
e.printStackTrace();
}finally{
if(process!=null) process.destroy();
process=null;
}
}
}
4. Runtime.exec() 不等同于直接执行command line命令！
啊，我算是在这里吃了苦头了。Runtime.exec()很有局限性，对有些命令不能直接把command line里的内容当作String参数传给exec().
比如重定向等命令。举个例子:
javap -l xxx > output.txt
这时要用到exec的第二种重载，即input 参数为String[]:
Process p = Runtime.getRuntime().exec(new String[]{"/bin/sh","-c","javap -l xxx > output.txt"});
?
?
??Process ps = Runtime.getRuntime().exec(cmd);
??BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream()));
??StringBuffer sb = new StringBuffer();
??String line;
??while ((line = br.readLine()) != null) {
??sb.append(line).append("\n");
??}
??String result = sb.toString();
??System.out.println(result);
