命令行运行Java

  很久没在命令行运行Java了，今天突然要运行一个觉得是在是生疏，虽然之前已有同样的经过，可惜没记录下来，吃一堑长一智，这次必须得记录下来了。

 

   我首先遇到的第一个问题是编码问题，因为我是在eclipse上写好的一个测试类ApacheStatusStatistic.java，并且能在eclipse上能正确运行。但是当我把这个文件拷贝文件 E:\test目录下，并在命令行执行时，其报“需要为 class,interface或enum....”错误，详情如下：

经多翻查找，终于知道其为编码问题，原来在ecplise环境中的编码是UTF-8,改为ANSI就解决了。

  遇到的第二个问题是编译运行的问题。我的类如下：

package apache;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.util.HashMap;
import java.util.Map;

public class ApacheStatusStatistic {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			java.net.URL url = new java.net.URL("http://www.apache.org/server-status?auto");
			BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
			
			String open = "Open";
			String waiting = "Waiting";
			String readingRequest = "Reading request";
			String sendingReply = "Sending reply";
			String keepingAlive = "Keeping alive";
			String dnsLookup = "DNS lookup";
			String logging = "Logging";
			// 额外的
			String startingUp = "Starting up";
			String closingConnection = "Closing connection";
			String gracefullyFinishing = "Gracefully finishing";
			String idleCleanupofWorker = "Idle cleanup of worker";

			Map<String, Integer> data = new HashMap<String, Integer>();
			data.put(open, 0);
			data.put(waiting, 0);
			data.put(readingRequest, 0);
			data.put(sendingReply, 0);
			data.put(keepingAlive, 0);
			data.put(dnsLookup, 0);
			data.put(logging, 0);
			// 额外的
			data.put(startingUp, 0);
			data.put(closingConnection, 0);
			data.put(gracefullyFinishing, 0);
			data.put(idleCleanupofWorker, 0);

			String str;
			System.out.println("基本统计数据如下:");
			while ((str = in.readLine()) != null) {
				if (str.startsWith("Scoreboard:")) {
					String scoreboard = str.substring(11);
					// System.out.println(scoreboard);
					for (int i = 0; i < scoreboard.length(); i++) {
						char c = scoreboard.charAt(i);
						switch (c) {
						case '_':
							data.put(waiting, data.get(waiting) + 1);
							break;
						case 'S':
							data.put(startingUp, data.get(startingUp) + 1);
							break;
						case 'R':
							data.put(readingRequest, data.get(readingRequest) + 1);
							break;
						case 'W':
							data.put(sendingReply, data.get(sendingReply) + 1);
							break;
						case 'K':
							data.put(keepingAlive, data.get(keepingAlive) + 1);
							break;
						case 'D':
							data.put(dnsLookup, data.get(dnsLookup) + 1);
							break;
						case 'C':
							data.put(closingConnection, data.get(closingConnection) + 1);
							break;
						case 'L':
							data.put(logging, data.get(logging) + 1);
							break;
						case 'G':
							data.put(gracefullyFinishing, data.get(gracefullyFinishing) + 1);
							break;
						case 'I':
							data.put(idleCleanupofWorker, data.get(idleCleanupofWorker) + 1);
							break;
						/** Open slot with no current process */
						case '.':
							data.put(open, data.get(open) + 1);
							break;
						}
					}
				} else {
					System.out.println(str);
				}
			}
			
			System.out.println("状态统计数据如下:");
			System.out.println(open + ":" + data.get(open));
			System.out.println(waiting + ":" + data.get(waiting));
			System.out.println(readingRequest + ":" + data.get(readingRequest));
			System.out.println(sendingReply + ":" + data.get(sendingReply));
			System.out.println(keepingAlive + ":" + data.get(keepingAlive));
			System.out.println(dnsLookup + ":" + data.get(dnsLookup));
			System.out.println(logging + ":" + data.get(logging));
			/** 额外的*/
			System.out.println(startingUp + ":" + data.get(startingUp));
			System.out.println(closingConnection + ":" + data.get(closingConnection));
			System.out.println(gracefullyFinishing + ":" + data.get(gracefullyFinishing));
			System.out.println(idleCleanupofWorker + ":" + data.get(idleCleanupofWorker));
			
			in.close();
		} catch (MalformedURLException e) {
		} catch (IOException ee) {
		}
	}
}

   我编译并运行，但结果却是“no class def found error”，详情如下：

 后来经过调查时，运行编译好的文件时，必须进入其所在的目录如下图所示：

 

但我运行时却报：Exception in thread "main" java.lang.NoClassDefFoundError: ApacheStatusStatistic (wrong name: apache/ApacheStatusStatistic)，详情如下：

经过调查因为包的问题，如果Java类有包名，你必须建相应的包文件夹并把文件编译或拷贝到到相应的文件夹下，如这里

我得在E:\test下创建文件夹apache并把ApacheStatusStatistic.class拷贝到这个文件夹下。并且必须在命令行指定包名，执行如下才成功运行：

终于搞定，铭刻于心呀