treesubst.java

java xml开发指南（初学者推荐）Java Xml 编程指南书籍源码

package MyNa.xml;

import MyNa.utils.*;
import java.io.*;
import java.util.*;
import java.sql.SQLException;

import org.w3c.dom.Element;
import org.w3c.dom.Node;



import org.w3c.dom.Node;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Attr;

/* sax, parser, XmlDocument are used only in main */
import org.xml.sax.SAXParseException;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import com.sun.xml.parser.Resolver;
import com.sun.xml.tree.XmlDocument;


public class TreeSubst {

// handles an xml template with no DTD; output to a Writer. 
// the idea is that the user takes a sample (minimal) of
// xml, which may well have a DTD; replaces constants by
// variables whose values will be provided by an env; 
// wraps nodes within "substrow" nodes which are to be
// filled in by the next row, and substrowlist nodes to
// be filled in by however many rows there are. If
// substrow is called with no input, it generates no
// output, but sets a flag so substerr does generate
// output.  Nodes which TreeSubst doesn't understand
// are simply echoed (recursively); there is at present
// no way to "quote", but it would be okay to add a
// substquote node which means "echo everything below
// this node without substitutions.


// We start with an Env, which may or may not contain a
// DBHandler to connect us with a database. If there is no
// DBHandler, there can't be dbOperation attributes. The Env
// may be generated by a RowSeq in which case
// substrow, substerr and substrowlist are legitimate;
// <substrowlist enumerateThrough="StrSeq" name="FieldName">
//  may also be used to generate items from StrSeqs in an Env.

// in general, use this by identifying the top <template>
// node nd, the output out
   Logger lg;
   Writer out;
   Env defs;
   RowSeq rows;

   int[]index;
   int curIndex;
   boolean substFailure;

public TreeSubst(){
   lg=new Logger();
   out=new PrintWriter(System.out);
   defs=new Env();   rows=null;
   index=new int[20];curIndex=-1;
   substFailure=false;
   lg.logIt("TreeSubst default initialization");
}
public void setOut(Writer o){out=o;}
public void setDefs(Env e){defs=e;}
public void setRows(RowSeq re){
  rows=re; 
  defs=re.getRow();
}
public TreeSubst(Env e,Writer o){
   lg=new Logger();
  out=o; defs=e; rows=null;
  index=new int[20];curIndex=-1;
  substFailure=false;
   lg.logIt("TreeSubst Env+Writer initialization");
}
public TreeSubst(RowSeq e,Writer o){
   lg=new Logger();
  rows=e;out=o; defs=e.getRow();
  index=new int[20];curIndex=-1;
  substFailure=false;
   lg.logIt("TreeSubst RowSeq+Writer initialization");
}

// the core strategy is to echo an xml document; then echo with changes.
/* BEGIN basic echo functionality: */

public void echoChildren(Node theFirst, Writer out)
                    throws IOException {
  while(null!=theFirst){
     echoNode(theFirst,out);
     theFirst=theFirst.getNextSibling();
     }
}
public void echoDTD(String theName,NamedNodeMap theEntities,
                      NamedNodeMap theNotes,Writer out)
                    throws IOException {
    out.write("<!DOCTYPE "); out.write(theName);
      out.write(" ["); 
      echoAttributes(theEntities,out);
    out.write("]\n [");
    echoAttributes(theNotes,out);
    out.write("]>\n");
}
public void echoAttributes(NamedNodeMap attrs,Writer out)
                    throws IOException {
  int N=attrs.getLength();
  for(int i=0; i<N; i++)echoNode(attrs.item(i),out);
}

public void echoNode(Node theNode)
                    throws IOException {echoNode(theNode, out);}

public void echoNode(Node theNode,Writer out)
                    throws IOException {
  short code=theNode.getNodeType();
  switch(code){
    case Node.ATTRIBUTE_NODE: 
      Attr at=(Attr)theNode;
      out.write(" ");
      out.write(at.getName());
      out.write("='");
      out.write(at.getValue());
      out.write("'");
      return;
    case Node.CDATA_SECTION_NODE: 
      out.write("<CDATA[[");
      out.write(theNode.getNodeValue());
      out.write("]]>");
      return;
    case Node.COMMENT_NODE: 
      out.write("<!-- ");
      out.write(theNode.getNodeValue());
      out.write("-->\n");
      return;
    case Node.DOCUMENT_FRAGMENT_NODE: // we can't reconstitute this; dump it
    case Node.DOCUMENT_NODE: 
      echoChildren(theNode.getFirstChild(),out);
      return;
    case Node.DOCUMENT_TYPE_NODE: 
      DocumentType dT=(DocumentType)theNode;
      echoDTD(dT.getName(),dT.getEntities(),dT.getNotations(),out);
      return;
    case Node.ELEMENT_NODE: 
      out.write("<"); out.write(theNode.getNodeName());
      echoAttributes(theNode.getAttributes(),out);
      Node kid=theNode.getFirstChild();
      if(kid==null) out.write("/>\n");
      else {
        out.write(">");
        echoChildren(kid,out);
        out.write("</");
        out.write(theNode.getNodeName());
        out.write(">\n");
        }
      return;
   case Node.ENTITY_NODE: 
       out.write("<ENTITY: "); out.write(theNode.getNodeName());
       out.write(">"); out.write(theNode.getNodeValue());
       out.write("</"); out.write(theNode.getNodeName());
       out.write(">\n");
       return;
   case Node.ENTITY_REFERENCE_NODE: 
       out.write("<ENTITY_REF: "); out.write(theNode.getNodeName());
       out.write("/>\n");
       return;
   case Node.NOTATION_NODE : 
       out.write("<NOTATION: "); out.write(theNode.getNodeName());
       out.write("/>\n");
       return;
   case Node.PROCESSING_INSTRUCTION_NODE: 
       out.write("<? "); out.write(theNode.getNodeName());
       out.write(" "); out.write(theNode.getNodeValue());
       out.write(" ?>\n");
       return;
    case Node.TEXT_NODE: 
      out.write(theNode.getNodeValue());
      return;
    default:return;
  } 
}

/* END basic echo functionality */
// we're going to be echoing again, but via lookUp:

static String substMarker="!=";

public String getKey(String S)throws TemplateException{
// S may be null, ibblebibble, "!=dbUser", "!=FieldName[3]", &c.
  if(S==null)return S;
  if(!S.startsWith(substMarker))return S;
   S=S.substring(2,S.length());
  int n=0;
  if(S.endsWith("]")){
    int i=S.lastIndexOf("[");
    n=Integer.parseInt(S.substring(i+1,S.length()-1));
    S=S.substring(0,i);
    }
  return getKeyIndex(S,n);
}
public String getKeyIndex(String S, int n)throws TemplateException{
  if(n==0){
     String R=defs.getStr(S);
     if(null!=R)return R;
     throw new TemplateException("no definition for key "+S);
     }
  if(n<0)n=index[curIndex];
  String[] A=defs.getStrSeq(S);
  if(A==null || A.length==0 || A.length<n)
    throw new TemplateException("no definition for key "+S+"["+n+"]");
  return A[n-1];
}

// we now extend the basic echo, by allowing special tags for elements,
// with a "chooseRule" function which interprets tags. echoChildren
// becomes substChildren, echoAttributes becomes substAttributes.

public void substChildren(Node theFirst, Writer out)
                    throws IOException,TemplateException {
  while(null!=theFirst){
     substNode(theFirst,out);
     theFirst=theFirst.getNextSibling();
     }
}

/* no substDTD function; we'll just use echoDTD */

public void substAttributes(NamedNodeMap attrs,Writer out)
                    throws IOException,TemplateException {
  int N=attrs.getLength();
  for(int i=0; i<N; i++)substNode(attrs.item(i),out);
}

public void substNode(Node theNode)
                    throws IOException,TemplateException {
  substNode(theNode, out);}

public void substNode(Node theNode,Writer out)
                    throws IOException,TemplateException {
  short code=theNode.getNodeType();
  switch(code){
    case Node.ATTRIBUTE_NODE: 
      Attr at=(Attr)theNode;
      out.write(" ");
      out.write(at.getName());
      out.write("='");
      out.write(getKey(at.getValue()));
      out.write("'");
      return;
    case Node.CDATA_SECTION_NODE: 
      out.write("<CDATA[[");
      out.write(theNode.getNodeValue());
      out.write("]]>");
      return;
    case Node.COMMENT_NODE: 
      out.write("<!-- ");
      out.write(theNode.getNodeValue());
      out.write("-->\n");
      return;
    case Node.DOCUMENT_FRAGMENT_NODE: // can't reconstitute, just dump it