import org.apache.hadoop.maven.plugin.util.Exec; //导入依赖的package包/类
/**
 * Determines which SCM is in use (Subversion, git, or none) and captures
 * output of the SCM command for later parsing.
 * 
 * @return SCM in use for this build
 * @throws Exception if any error occurs attempting to determine SCM
 */
private SCM determineSCM() throws Exception {
  Exec exec = new Exec(this);
  SCM scm = SCM.NONE;
  scmOut = new ArrayList<String>();
  int ret = exec.run(Arrays.asList(svnCommand, "info"), scmOut);
  if (ret == 0) {
    scm = SCM.SVN;
  } else {
    ret = exec.run(Arrays.asList(gitCommand, "branch"), scmOut);
    if (ret == 0) {
      ret = exec.run(Arrays.asList(gitCommand, "remote", "-v"), scmOut);
      if (ret != 0) {
        scm = SCM.NONE;
        scmOut = null;
      } else {
        ret = exec.run(Arrays.asList(gitCommand, "log", "-n", "1"), scmOut);
        if (ret != 0) {
          scm = SCM.NONE;
          scmOut = null;
        } else {
          scm = SCM.GIT;
        }
      }
    }
  }
  if (scmOut != null) {
    getLog().debug(scmOut.toString());
  }
  getLog().info("SCM: " + scm);
  return scm;
}
 

import org.apache.hadoop.maven.plugin.util.Exec; //导入依赖的package包/类
/**
 * Determines which SCM is in use (Subversion, git, or none) and captures
 * output of the SCM command for later parsing.
 * 
 * @return SCM in use for this build
 * @throws Exception if any error occurs attempting to determine SCM
 */
private SCM determineSCM() throws Exception {
  Map<String, String> env = System.getenv();
  if (env.containsKey("COMPONENT_HASH")) {
      return SCM.GIT;
  }
  Exec exec = new Exec(this);
  SCM scm = SCM.NONE;
  scmOut = new ArrayList<String>();
  int ret = exec.run(Arrays.asList(svnCommand, "info"), scmOut);
  if (ret == 0) {
    scm = SCM.SVN;
  } else {
    ret = exec.run(Arrays.asList(gitCommand, "branch"), scmOut);
    if (ret == 0) {
      ret = exec.run(Arrays.asList(gitCommand, "remote", "-v"), scmOut);
      if (ret != 0) {
        scm = SCM.NONE;
        scmOut = null;
      } else {
        ret = exec.run(Arrays.asList(gitCommand, "log", "-n", "1"), scmOut);
        if (ret != 0) {
          scm = SCM.NONE;
          scmOut = null;
        } else {
          scm = SCM.GIT;
        }
      }
    }
  }
  if (scmOut != null) {
    getLog().debug(scmOut.toString());
  }
  getLog().info("SCM: " + scm);
  return scm;
}