Java执行外部程序

Java执行外部程序其实是一个简单的操作

首先取得运行环境（JVM）
然后直接执行程序命令就可以

try {
Process proc = Runtime.getRuntime().exec("ipconfig");
//如果要取得执行命令的输出，那么可以通过proc.getInputStream()取得
DataInputStream in = new DataInputStream(proc.getInputStream());
Charset ch = Charset.forName("gb2312");

BufferedReader reader = new BufferedReader(new InputStreamReader(in, ch));

String str = reader.readLine();

while (null != str) {
System.out.println(str);
str = reader.readLine();
}
} catch (IOException e) {
e.printStackTrace();
}

下面是相关的JDK官方注解
java.lang.Process

The

ProcessBuilder.start()

and

Runtime.exec

methods create a native process and return an instance of a subclass of

Process

that can be used to control the process and obtain information about it. The class

Process

provides methods for performing input from the process, performing output to the process, waiting for the process to complete, checking the exit status of the process, and destroying (killing) the process.
The methods that create processes may not work well for special processes on certain native platforms, such as native windowing processes, daemon processes, Win16/DOS processes on Microsoft Windows, or shell scripts. The created subprocess does not have its own terminal or console. All its standard io (i.e. stdin, stdout, stderr) operations will be redirected to the parent process through three streams (

getOutputStream()

,

getInputStream()

,

getErrorStream()

). The parent process uses these streams to feed input to and get output from the subprocess. Because some native platforms only provide limited buffer size for standard input and output streams, failure to promptly write the input stream or read the output stream of the subprocess may cause the subprocess to block, and even deadlock.
The subprocess is not killed when there are no more references to the

Process

object, but rather the subprocess continues executing asynchronously.
There is no requirement that a process represented by a

Process

object execute asynchronously or concurrently with respect to the Java process that owns the

Process

object.
Process java.lang.Runtime.exec(String command) throws IOException
Executes the specified string command in a separate process.
This is a convenience method. An invocation of the form exec(command) behaves in exactly the same way as the invocation

exec

(command, null, null).
Parameters:command a specified system command.Returns:A new

Process

object for managing the subprocessThrows:SecurityException - If a security manager exists and its

checkExec

method doesn't allow creation of the subprocessIOException - If an I/O error occursNullPointerException - If

command

is

null

IllegalArgumentException - If

command

is emptySee Also:exec(String[], String[], File)ProcessBuilder