如何通过Java调用系统命令，如ping 127.0.0.1、java -version等？
> 简单的例子
package com.nicchagil.callpython.No001无参数调用; import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader; public class HowToCallSystemCommand { public static void main(String[] args) {
BufferedReader in = null;
try {
/* 调用、输出 */
Process process = Runtime.getRuntime().exec("ping 127.0.0.1");
in = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
System.out.println(line);
} /* 判断是否正常 */
int waitFor = process.waitFor();
System.out.println("waitFor -> " + waitFor);
if (process.waitFor() == 0) {
System.out.println("Normal termination.");
} else {
System.out.println("Abnormal termination.");
}
} catch (Exception e) {
// TODO
e.printStackTrace();
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
// TODO
e.printStackTrace();
}
}
System.out.println("Done...");
}
} }
执行后，发现对于“ping 127.0.0.1”能完整的打印出日志，而对于“java -version”却无日志输出，原因在于它们输出的级别不同。
于是，作了下简单修改。
package com.nicchagil.callpython.No001无参数调用; import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader; public class HowToCallSystemCommand { public static void main(String[] args) {
BufferedReader inputBufferedReader = null;
BufferedReader errorBufferedReader = null;
try {
/* 调用、输出 */
Process process = Runtime.getRuntime().exec("java -version");
inputBufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
errorBufferedReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
String line = null; System.out.println("Input Stream -> ");
while ((line = inputBufferedReader.readLine()) != null) {
System.out.println(line);
} System.out.println("Error Stream -> ");
while ((line = errorBufferedReader.readLine()) != null) {
System.out.println(line);
} /* 判断是否正常 */
int waitFor = process.waitFor();
System.out.println("waitFor -> " + waitFor);
if (process.waitFor() == 0) {
System.out.println("Normal termination.");
} else {
System.out.println("Abnormal termination.");
}
} catch (Exception e) {
// TODO
e.printStackTrace();
} finally {
if (inputBufferedReader != null) {
try {
inputBufferedReader.close();
} catch (IOException e) {
// TODO
e.printStackTrace();
}
}
System.out.println("Done...");
}
} }
分别执行两个命令，查询日志，发现OK了，哈哈哈。