如何使用Commons Exec将命令的输出捕获为字符串？

他是我发现的东西：

import java.io.ByteArrayOutputStream;import org.apache.commons.exec.CommandLine;import org.apache.commons.exec.DefaultExecutor;import org.apache.commons.exec.Executor;import org.apache.commons.exec.PumpStreamHandler;public String execToString(String command) throws Exception {    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();    CommandLine commandline = CommandLine.parse(command);    DefaultExecutor exec = new DefaultExecutor();    PumpStreamHandler streamHandler = new PumpStreamHandler(outputStream);    exec.setStreamHandler(streamHandler);    exec.execute(commandline);    return(outputStream.toString());}