smartpropertytag.java

招标投标网上系统

/*
 * $Id: SmartPropertyTag.java,v 1.4 2001/10/26 22:55:55 ro89390 Exp $
 * Copyright 2000 Sun Microsystems, Inc. All rights reserved.
 * Copyright 2000 Sun Microsystems, Inc. Tous droits r?erv?.
 */

package com.neusoft.taglibs.smart;

import java.io.*;
import java.lang.reflect.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

/**
 *
 * This class allows you to retrieve a parameter from the request and output it to the page
 * This should allow you to avoid expressions for extracting parameter info.
 *
 */

public class SmartPropertyTag
    extends TagSupport {

  private Object bean = null;
  private String id = null;
  private String property = null;
  private String format = null;
  private String localeString = null;
  private String numberFormatPattern = null;
  private String precisionString = null;
  private String scope = null;

  public SmartPropertyTag() {
    super();
  }

  public void setId(String id) {
    this.id = id;
  }

  public void setScope(String scope) {
    this.scope = scope;
  }

  /**
   * To be used when formatting currency
   *
   */
  public void setLocale(String localeString) {
    this.localeString = localeString;
  }

  /**
   * Support number format and currency format here.
   * When this is set ensure that the proper decile places are
   * supportted.
   *
   */
  public void setFormatText(String format) {
    this.format = format;
  }

  /**
   * Only used when formattting numbers
   *
   */
  public void setNumberFormatPattern(String numberFormatPattern) {
    this.numberFormatPattern = numberFormatPattern;
  }

  public void setPrecision(String precisionString) {
    this.precisionString = precisionString;
  }

  public void setProperty(String property) {
    this.property = property;
  }

  public int doStartTag() throws JspTagException {
    // check if beans tag is in list tag
      // try to find the bean in the scope
      if (scope.toLowerCase().equals("request")) {
        bean = pageContext.getRequest().getAttribute(id);
      }
      else if (scope.toLowerCase().equals("session")) {
        bean = pageContext.getSession().getAttribute(id);
      }
      else if (scope.toLowerCase().equals("page")) {
        bean = pageContext.getAttribute(id);
      }
      // otherwise create a new one and put it in the scope
      if (bean == null) {
        throw new JspTagException("SmartPropertyTag: Object not found: " + id);
      }

    return SKIP_BODY;
  }

  public int doEndTag() throws JspTagException {
    // print out attribute
    try {
      JspWriter out = pageContext.getOut();
      String targetText = getText();
      //if (format != null) targetText = formatText(targetText);
      out.print(targetText);
    }
    catch (IOException ioe) {
      System.err.println("SmartPropertyTag: Error printing attribute: " + ioe);
      throw new JspTagException(
          "SmartPropertyTag: IO Error printing attribute.");
    }
    return (EVAL_PAGE);
  }

  /**
   * Using the current Object use reflection to obtain the
   * String data from the element method the same as a JavaBean
   * would use:
   * <br><br>e.g. a getXXXX method which has no parameters
   * <br>    The target method is the property attribute
   *
   * The default method that is called is the toString method on the object.
   */
  private String getText() throws JspTagException {

    String targetMethod = null;
    if (property == null) {
      targetMethod = "toString";
    }
    else {
      targetMethod = "get" + property.substring(0, 1).toUpperCase() +
          property.substring(1, property.length());

    }
    Object returnValue = null;
    try {
      // no arguments are needed
      Class[] args = {};
      Object[] params = {};
      Method m = bean.getClass().getMethod(targetMethod, args);
      if (m == null) {
        throw new JspTagException(
            "SmartPropertyTag: There is no method by the name of " +
            targetMethod);
      }
      returnValue = m.invoke(bean, params);
    }
    catch (java.lang.NoSuchMethodException ex) {
      throw new JspTagException("SmartPropertyTag: Method for property " +
                                property + " not found.");
    }
    catch (java.lang.reflect.InvocationTargetException ex) {
      throw new JspTagException("SmartPropertyTag: Error calling method " +
                                targetMethod + ":" + ex);
    }
    catch (java.lang.IllegalAccessException ex) {
      throw new JspTagException("SmartPropertyTag: Error calling method " +
                                targetMethod + ":" + ex);
    }
    // do casting of Integers and Dobules here
    if (returnValue instanceof java.lang.String) {
      return (String) returnValue;
    }
    else if (returnValue instanceof java.lang.Integer) {
      return ( (Integer) returnValue).toString();
    }
    else if (returnValue instanceof java.lang.Double) {
      return ( (Double) returnValue).toString();
    }
    else if (returnValue instanceof java.lang.Float) {
      return ( (Float) returnValue).toString();
    }
    else if (returnValue == null) {
      return "";
    }
    else {
      return returnValue + "";
    }
  }

}