Java调用外部文件

Demo

   涉及到执行外部函数时的环境变量

   使用LineNumberReader处理执行结果

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.util.Iterator;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.dahuazwan.backup.pojo.BackupPojo;

public class Backup {
	private static Log log = LogFactory.getLog(Backup.class);
	
 
	/**
	 * 
	 * @param backupPojo
	 * @param iAllback true：备份全部；否则备份指定表
	 */
	public void execute(BackupPojo backupPojo,boolean iAllback){
		ProcessBuilder pb = new ProcessBuilder("cmd","/c",backupPojo.toBackupSql(iAllback));
		// 设置环境变量
		Map<String, String> env = pb.environment();
		// 设置新的环境变量
		String sMysqlbindir = backupPojo.getsMysqlbindir();
		if(sMysqlbindir != null && !"".equals(sMysqlbindir)){
			this.changeEnv(env, "path", backupPojo.getsMysqlbindir(), false);
		}
		
//		// 打印
//		Iterator<String> it = env.keySet().iterator();
//		while(it.hasNext()){
//			String key = it.next();
//			System.out.println(key + " = " + env.get(key));
//			
//		}
 
		Iterator<String> it = env.keySet().iterator();
		while(it.hasNext()){
			String key = it.next();
			System.out.println(key + " = " + env.get(key));
			
		}
		
	//	pb.directory();
		try {
			Process p = pb.start();
			//打印错误流信息
			LineNumberReader lnr = new LineNumberReader(new InputStreamReader(p.getErrorStream()));
			String s;
		 	while( (s = lnr.readLine()) != null){
		 		// 打印错误信息
		 		log.error(s);
		 	}
		 	// 如果行号为0，则无错误信息，执行命令成功，否则失败
		 	if(lnr.getLineNumber() == 0){
		 		log.info(" back up database ok !");
		 	}else{
		 		log.info(" back up database failure ! cmd = \" " + backupPojo.toBackupSql(iAllback) + "\"") ;
		 	}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			log.info(" back up database failure ! cmd = \" " + backupPojo.toBackupSql(iAllback) + "\"") ;
			log.error(e);
		}
	}
	
	/**
	 * 
	 * @param sName 非空
	 * @param sValue 
	 * @param isAppend true：append：false：替换
	 */
	public void changeEnv(Map<String, String> env,String sName,String sValue, boolean isAppend ){
		// 全部小写
		Iterator<String> it = env.keySet().iterator();
		while(it.hasNext()){
			String sKey = it.next();
			if(sName.equalsIgnoreCase(sKey)){
				if(isAppend){
					// append
					String sT = env.get(sKey);
					if(sT == null || "".equals(sT)){
						sT = sValue;
					}else{
						sT = sT + ";" + sValue;
					}
					env.put(sKey, sT);
				}else{
					//替换
					env.put(sKey, sValue);
				}
				
			}
 
		}
	}
	
}

 

Demo 2：

比第一个好：

public class DosRun {
	private static Log log = LogFactory.getLog(DosRun.class);
	
	/**
	 * 执行外部程序，此程序无输入流
	 * @param sCommand
	 */
	public static void execute(List<String> lCommand){
		try{
			if(log.isInfoEnabled()){
				log.info("Command = " + lCommand);
			}
 
			ProcessBuilder pb = new ProcessBuilder(lCommand);
			pb.redirectErrorStream(true); //错误和正确信息合并输出
		 
			Process p = pb.start();
			p.getOutputStream().close(); //关不输出
		 		 
			// 打印处理消息
			String sInfo = readInputStream(p.getInputStream());
			log.info("Info = " + sInfo);
			int iResult = p.exitValue();
			if(iResult == 0){
				log.info(" result = " +p.exitValue() + "execute command success! Command = " + lCommand);
			}else{
				log.info(" result = " +p.exitValue() + "execute command failure! Command = " + lCommand);
			}
		}catch(Exception e){
			throw new RuntimeException(e);
		}
	}
	
	/**
	 * 执行程序，该程序由输入流
	 * @param lCommand
	 * @param sFile 成员要接收的数据文件
	 */
	public static void execute(List<String> lCommand, String sFile){
		try{
			if(log.isInfoEnabled()){
				log.info("Command = " + lCommand);
			}
 
			ProcessBuilder pb = new ProcessBuilder(lCommand);
			pb.redirectErrorStream(true); //错误和正确信息合并输出
		 
			Process p = pb.start();
		
			FileInputStream fis = new FileInputStream(sFile);
			OutputStream os = p.getOutputStream();
			byte[] b = new byte[8192];
			int num = 0;
			while((num = fis.read(b) )!= -1){
				os.write(b,0,num);
			}
			os.close();
			 
			// 打印处理消息
			String sInfo = readInputStream(p.getInputStream());
			log.info("Info = " + sInfo);
			int iResult = p.exitValue();
			if(iResult == 0){
				log.info(" result = " +p.exitValue() + "execute command success! Command = " + lCommand);
			}else{
				log.info("  result = " +p.exitValue() + "execute command failure! Command = " + lCommand);
			}
		}catch(Exception e){
			throw new RuntimeException(e);
		}
	}
	
 
	
	/**
	 * 读取流中数据，并返回给用户
	 * @return
	 * @throws IOException 
	 */
	private static String readInputStream(InputStream in) throws IOException{
		StringBuilder sb = new StringBuilder();
		LineNumberReader lnr = new LineNumberReader(new InputStreamReader(in));
		String s;
	 	while( (s = lnr.readLine()) != null){
	 		// 打印信息
	 		System.out.println(s);
	 		sb.append(s).append("\r\n");
	 	}
	 	return sb.toString();
	}
	
 
}

 

扫描二维码关注公众号，回复： 1282669 查看本文章

参考文献

• [java调用外部可执行程序] 2. java输入输出重定向 取得Runtime.getRuntime().exec("cmd /c dir")的输入输出； 利用ProcessBuilder来创建Process对象，执行外部可执行程序；如何协调外部进程与当前Java进程(waitFor方法和执行DOS的内部命令)
• Java调用外部程序命令   阅读ProcessBuilder源代码后对List参数的空格处理说明；将标准输出和错误输出合并，一起读出来或者在另外的线程中读出来；如果不使用标准输入，建议close
• 使用ProcessBuilder执行本地命令 Demo