stockclient.java

来自「weblogic应用全实例」· Java 代码 · 共 233 行

//声明
package examples.xml.http;

import java.util.*;
import java.net.*;
import org.xml.sax.*;
import java.io.*;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.SAXParser;

/**
 * 这个示例演示如何创建和操作 XML 数据，并把它从客户端传送到服务器端的servlet. 
 */

public class StockClient extends HandlerBase {


  /** 打印 writer. */
  private PrintWriter out;

  /** 缺省的构造器 */
  public StockClient() {
      try {
          out = new PrintWriter(new OutputStreamWriter(System.out, "UTF8"));
      } catch (UnsupportedEncodingException e) {
      }
  }

  /**
   * 从命令行运行这个示例
   * <p>
   * <tt>java xml.sax.StockClient t3://localhost:7001/stock BEAS</tt>

   */

  public static void main(String[] args) {
    if ((args.length < 1)|| (args[0].indexOf("StockServlet")== -1)) {
      System.out.println("用法： java examples.xml.http.StockClient "
                         + "ServletURL");
      System.out.println("例如：Example:java examples.xml.http.StockClient "
                         + "http://localhost:7001/StockServlet");
      
    }
    else {
                       
       try {
         URL url = new URL(args[0]);

         BufferedReader msgStream = new BufferedReader(new InputStreamReader(System.in));
         String line=null;
         boolean quitNow = false;
         boolean buy = false;
         boolean sell = false;
         boolean beas = false;
         boolean msft = false;
         boolean transactionSent = false;

         do {
           transactionSent = false;

           //从户用端获取动作
           System.out.print("动作 (\"Buy\" or \"Sell\", \"quit\" to quit): ");
           line = msgStream.readLine();
           if (line != null && line.trim().length() != 0) {
             quitNow = line.equalsIgnoreCase("quit");
             buy = line.equalsIgnoreCase("buy");
             sell = line.equalsIgnoreCase("sell");
             if ((buy || sell) && !quitNow) {
               do {

                 //获取股票代号
                 System.out.print("代码 (\"BEAS\" or \"MSFT\", \"quit\" to quit): ");
                 line = msgStream.readLine();
                 if (line != null && line.trim().length() != 0) {
                   quitNow = line.equalsIgnoreCase("quit");
                   beas = line.equalsIgnoreCase("BEAS");
                   msft = line.equalsIgnoreCase("MSFT");
                   if ((beas || msft) && !quitNow) {
                     do {

                       // 获取数量
                       System.out.print("股票笔数 (\"quit\" to quit): ");
                       line = msgStream.readLine();
                       if (line != null && line.trim().length() != 0) {
                         quitNow = line.equalsIgnoreCase("quit");
                         if (!quitNow) {

                           // 确保用户输入的是数字
                           boolean isInteger = false;
                           try {
                             Integer.parseInt(line);
                             isInteger = true;
                           } catch (NumberFormatException nfe) {
                             isInteger = false;
                           }
                           if (isInteger) {
                             System.out.println("发送信息...");
                             URLConnection urlc = url.openConnection();
                             urlc.setRequestProperty("Content-Type","text/xml");
                             urlc.setDoOutput(true);
                             urlc.setDoInput(true);
                             PrintWriter pw = new PrintWriter(new 
                                    OutputStreamWriter(urlc.getOutputStream()), true);

                             // 发送 xml 到 servlet
                             pw.println("<?xml version='1.0'?>");
                             
                             // 声明文档类型
                             pw.println("<!DOCTYPE stocktrade PUBLIC 'examples.xml.http-stocktrade' 'stocktrade.dtd'>");

                             // 设置股票交易指令
                             pw.print("<stocktrade ");
                             pw.print("action = "+ (buy ? "'buy' " : "'sell' "));
                             pw.print("symbol = "+ (beas ? "'BEAS' " : "'MSFT' ")); 
                             pw.print("numShares = '"+ line +"'"); 
                             pw.println(" />");

                             // 解析servlet返回的XML 
                             System.setProperty("javax.xml.parsers.SAXParserFactory", 
                               "weblogic.apache.xerces.jaxp.SAXParserFactoryImpl");
                             
                             SAXParserFactory fact = SAXParserFactory.newInstance();
                             SAXParser parser = fact.newSAXParser();
                             org.xml.sax.Parser saxp = parser.getParser();

                             HandlerBase handler = new StockClient();
                             saxp.setDocumentHandler(handler);
                             saxp.setErrorHandler(handler);
                             saxp.parse(new InputSource(new BufferedReader(
                                     new InputStreamReader(urlc.getInputStream()))));
                             transactionSent = true;
                           }
                         }
                       }
                     } while ( !quitNow && !transactionSent);
                   }
                 }
               } while ( !quitNow && !transactionSent);
             }
           }
        } while (! quitNow);

       }
       catch (FileNotFoundException fnfe) {
         System.out.println("[DTD not found] Please place the stocktrade.dtd "+
                            "file in the examplesXMLRegistry entity folder. "+
                            "See the example documentation for details.");
         fnfe.printStackTrace();
       } catch (Exception e) {
          e.printStackTrace();
       }
    }

  }

  //
  // 文档处理方法
  //


  /** 文档开始 */
  public void startDocument() throws SAXException {
    out.println("");
    out.println("Trade results:");
  } // startDocument()

  /** 元素开始 */
  public void startElement(String name, AttributeList attrs) throws SAXException {

      if (attrs != null) {
          int len = attrs.getLength();
          for (int i = 0; i < len; i++) {
              out.print(attrs.getName(i));
              out.print("=");
              out.println(attrs.getValue(i));
          }
          out.println(" ");
      }
  } 


  /** 文档结束 */
  public void endDocument() throws SAXException {
      out.flush();

  }

  //
  // 错误处理方法
  //

  /** 警告 */
  public void warning(SAXParseException ex) {
      System.err.println("[Warning] "+
                         getLocationString(ex)+": "+
                         ex.getMessage());
  }

  /** 可恢复错误 */
  public void error(SAXParseException ex) {
      System.err.println("[Error] "+
                         getLocationString(ex)+": "+
                         ex.getMessage());
  }

  /** 不可恢复错误 */
  public void fatalError(SAXParseException ex) throws SAXException {
      System.err.println("[Fatal Error] "+
                         getLocationString(ex)+": "+
                         ex.getMessage());
      throw ex;
  }

  /** 返回位置字符串 */
  private String getLocationString(SAXParseException ex) {
      StringBuffer str = new StringBuffer();

      String systemId = ex.getSystemId();
      if (systemId != null) {
          int index = systemId.lastIndexOf('/');
          if (index != -1) 
              systemId = systemId.substring(index + 1);
          str.append(systemId);
      }
      str.append(':');
      str.append(ex.getLineNumber());
      str.append(':');
      str.append(ex.getColumnNumber());   
      return str.toString();

  } 
}