sqltagcontext.java

本套系统采用了业界当前最为流行的beanAction组件

/*
 *  Copyright 2004 Clinton Begin
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package com.ibatis.sqlmap.engine.mapping.sql.dynamic.elements;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;

import com.ibatis.sqlmap.engine.mapping.parameter.ParameterMapping;

public class SqlTagContext {

  private StringWriter sw;
  private PrintWriter out;

  private HashMap attributes;

  private LinkedList removeFirstPrependStack;
  private LinkedList iterateContextStack;

  private ArrayList parameterMappings = new ArrayList();


  public SqlTagContext() {
    sw = new StringWriter();
    out = new PrintWriter(sw);
    attributes = new HashMap();
    removeFirstPrependStack = new LinkedList();
    iterateContextStack = new LinkedList();
  }

  public PrintWriter getWriter() {
    return out;
  }

  public String getBodyText() {
    out.flush();
    return sw.getBuffer().toString();
  }

  public void setAttribute(Object key, Object value) {
    attributes.put(key, value);
  }

  public Object getAttribute(Object key) {
    return attributes.get(key);
  }

  public void addParameterMapping(ParameterMapping mapping) {
    parameterMappings.add(mapping);
  }

  public List getParameterMappings() {
    return parameterMappings;
  }

  public boolean isEmptyRemoveFirtPrepend() {
    return removeFirstPrependStack.size() <= 0;
  }
  
  /**
   * examine the value of the top RemoveFirstPrependMarker object on the stack.
   * 
   * @return was the first prepend removed
   */
  public boolean peekRemoveFirstPrependMarker(SqlTag sqlTag) {
    
      RemoveFirstPrependMarker removeFirstPrepend = 
        (RemoveFirstPrependMarker) removeFirstPrependStack.get(1);
      
      return removeFirstPrepend.isRemoveFirstPrepend();
  } 
  
  /**
   * pop the first RemoveFirstPrependMarker once the recursion is on it's way out
   * of the recursion loop and return it's internal value.
   *
   * @param tag
   */
  public void popRemoveFirstPrependMarker(SqlTag tag) {
        
    RemoveFirstPrependMarker removeFirstPrepend = 
      (RemoveFirstPrependMarker) removeFirstPrependStack.getFirst();
    
    if(tag == removeFirstPrepend.getSqlTag()) {
      removeFirstPrependStack.removeFirst();
    }
  }
  
  /**
   * push a new RemoveFirstPrependMarker object with the specified internal state
   * 
   * @param tag
   */
  public void pushRemoveFirstPrependMarker(SqlTag tag) {
    
    if(tag.getHandler() instanceof DynamicTagHandler) {
      // this was added to retain default behavior
      if(tag.isPrependAvailable()) {
        removeFirstPrependStack.addFirst(
            new RemoveFirstPrependMarker(tag,true));
      } else {
        removeFirstPrependStack.addFirst(
            new RemoveFirstPrependMarker(tag,false));
      }
    } else if("true".equals(tag.getRemoveFirstPrepend())
        || "iterate".equals(tag.getRemoveFirstPrepend())){
      // you must be specific about the removal otherwise it
      // will function as ibatis has always functioned and add
      // the prepend
      removeFirstPrependStack.addFirst(
          new RemoveFirstPrependMarker(tag,true));
    } else if(!tag.isPrependAvailable() && 
        !"true".equals(tag.getRemoveFirstPrepend()) &&
        !"iterate".equals(tag.getRemoveFirstPrepend()) &&
        tag.getParent() != null) {
      // if no prepend or removeFirstPrepend is specified 
      // we need to look to the parent tag for default values
      if("true".equals(tag.getParent().getRemoveFirstPrepend())
          || "iterate".equals(tag.getParent().getRemoveFirstPrepend())) {
        removeFirstPrependStack.addFirst(
            new RemoveFirstPrependMarker(tag,true));
      }
    } else {
      removeFirstPrependStack.addFirst(
          new RemoveFirstPrependMarker(tag,false));
    }

  }
  
  /**
   * set a new internal state for top RemoveFirstPrependMarker object
   *
   */
  public void disableRemoveFirstPrependMarker() {
    ((RemoveFirstPrependMarker) removeFirstPrependStack.get(1)).setRemoveFirstPrepend(false);
  }

  public void reEnableRemoveFirstPrependMarker() {
    ((RemoveFirstPrependMarker) removeFirstPrependStack.get(0)).setRemoveFirstPrepend(true);
  }
  
  /**
   * iterate context is stored here for nested dynamic tags in
   * the body of the iterate tag
   * 
   * @param iterateContext
   */
  public void pushIterateContext(IterateContext iterateContext) {
    iterateContextStack.addFirst(iterateContext);
  }
  
  /**
   * iterate context is removed here from the stack when iterate tag is finished being
   * processed
   * 
   * @return the top element of the context stack
   */
  public IterateContext popIterateContext() {
    IterateContext retVal = null;
    if(!iterateContextStack.isEmpty()) {
      retVal = (IterateContext)iterateContextStack.removeFirst();
    }
    return retVal;
  }
  
  /**
   * iterate context is removed here from the stack when iterate tag is finished being
   * processed
   * 
   * @return the top element on the context stack
   */
  public IterateContext peekIterateContext() {
    IterateContext retVal = null;
    if(!iterateContextStack.isEmpty()) {
      retVal = (IterateContext)iterateContextStack.getFirst();
    }
    return retVal;
  }
  
}

/**
 * 
 * This inner class i used strictly to house whether the 
 * removeFirstPrepend has been used in a particular nested
 * situation. 
 * 
 * @author Brandon Goodin
 */
class RemoveFirstPrependMarker {
  
  private boolean removeFirstPrepend;
  private SqlTag tag;
  
  /**
   * 
   */
  public RemoveFirstPrependMarker(SqlTag tag, boolean removeFirstPrepend) {
    this.removeFirstPrepend = removeFirstPrepend;
    this.tag = tag;
  }
  
  /**
   * @return Returns the removeFirstPrepend.
   */
  public boolean isRemoveFirstPrepend() {
    return removeFirstPrepend;
  }
  
  /**
   * @param removeFirstPrepend The removeFirstPrepend to set.
   */
  public void setRemoveFirstPrepend(boolean removeFirstPrepend) {
    this.removeFirstPrepend = removeFirstPrepend;
  }
  
  /**
   * @return Returns the sqlTag.
   */
  public SqlTag getSqlTag() {
    return tag;
  }
  
}