xml2dbtables.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.Env;
import MyNa.utils.Logger;

import java.io.*;
import java.util.Stack;
import java.util.Hashtable;
import java.util.Enumeration;

import org.xml.sax.*;
import org.xml.sax.helpers.ParserFactory;
import com.sun.xml.parser.Resolver;


import java.sql.*;   // communicate with database


public class Xml2DBTables extends SAXMiniLanguage {
   // by construction, echo an input source to a database,
   // assuming the dbdata.dtd in which the xml itself
   // specifies the target database and provides user/pwd
   Connection theDBConnection=null; 
   Statement theCreateTableStatement;
   PreparedStatement theInsertPreparedStatement;


public Xml2DBTables (String fileName){
   super(fileName);
    theHandlerSet.put("row",new EndRowHandler());
    theHandlerSet.put("user-info",new EndUser_Info());
    theHandlerSet.put("header",new EndHeaderHandler());
    theHandlerSet.put("dbdata",new EnddbDataHandler());
    theHandlerSet.put("table",new EndTableHandler());
    theHandlerSet.put("headers",new EndHeadersHandler());
   lg.logIt("handlers placed");
}

class EndUser_Info extends EndHandler{
/*
the /user_info function,will open theDBConnection to
E.db_url with E.driver for E.uname with E.upass;
it will create theCreateTableStatement; these will be class vars rather than
in the environment. theCreateTableStatement will be used to create tables.
*/
  public EndUser_Info(){}
  public void doIt() throws SAXException {
    CallStackItem cSI=(CallStackItem)theCallStack.pop();
     lg.logIt("EndUserInfo doIt on "+cSI.name+"; kidnum="+cSI.kidNum);
    String driver=theEnv.getStr("driver");
    String db_url=theEnv.getStr("db_url");
    String uname=theEnv.getStr("uname");
    String upass=theEnv.getStr("upass");
  lg.logIt("driver="+driver+";db_url="+db_url+";uname="+uname+";upass="+upass);
   try{
      Class.forName(driver);
      theDBConnection= DriverManager.getConnection(db_url,uname,upass);
      theCreateTableStatement=theDBConnection.createStatement();
      lg.logIt("tableCreatestatement created.");
    }catch(ClassNotFoundException e)
      {throw new SAXException ("driver not found error", e);}
    catch(SQLException e)
      {throw new SAXException ("SQL error", e);}
  }
}
 class EndHeaderHandler extends EndHandler{
  public EndHeaderHandler(){} // leaves 
  public void doIt() throws SAXException {
    CallStackItem cSI=(CallStackItem)theCallStack.pop();
    lg.logIt("EndHeaderHandler doIt on "+cSI.name+"; kidnum="+cSI.kidNum);
    cSI.attrs.put("name",cSI.name);  // attrs never null for header
    pushVal(cSI.attrs);
  }
}
 class EndTableHandler extends EndHandler{
  public EndTableHandler(){}
  public void doIt() throws SAXException {
    try{
    CallStackItem cSI=(CallStackItem)theCallStack.pop();
    lg.logIt("EndTableHandler doIt on "+cSI.name+"; kidnum="+cSI.kidNum);
    theInsertPreparedStatement.close();
    }catch(SQLException e)
      {throw new SAXException ("SQL error", e);}
  }
}
 class EnddbDataHandler extends EndHandler{
  public EnddbDataHandler(){}
  public void doIt() throws SAXException {
    try{
    CallStackItem cSI=(CallStackItem)theCallStack.pop();
    lg.logIt("EnddbDataHandler doIt on "+cSI.name+"; kidnum="+cSI.kidNum);
    theCreateTableStatement.close();
    theDBConnection.close();
    }catch(SQLException e)
      {throw new SAXException ("SQL error", e);}
  }
}
 class EndRowHandler extends EndHandler{
  public EndRowHandler(){}
  public void doIt() throws SAXException {
    CallStackItem cSI=(CallStackItem)theCallStack.pop();
    lg.logIt("EndRowHandler doIt on "+cSI.name+"; kidnum="+cSI.kidNum);
    try{
    String [] names=(String[])theEnv.get("header_names");
    String [] types=(String[])theEnv.get("header_types");
    for(int i=1;i<=names.length;i++)
      theInsertPreparedStatement.setString(i,
                       (String)theEnv.get(names[i-1]));
    lg.logIt("strings all set");
    theInsertPreparedStatement.executeUpdate();
    theInsertPreparedStatement.clearParameters();
    }catch(SQLException e)
      {throw new SAXException ("SQL error", e);}
  }
}
 class EndHeadersHandler extends EndHandler{
/*
the /headers function picks up the attrlists; creates the table
if needed with theCreateTableStatement; it also opens 
theInsertPreparedStatement to insert new rows into the current
statement. This will be closed by /table.
 Notice that if there are five headers, then the valstack
consists of five attrlists  /headers uses them and pops them off,
but E.header_names becomes the list of names as an array of strings,
and E.header_types becomes the list of types as an array of strings,
while E.tableName becomes the table name itself.
Meanwhile, <table name="thetablename"> is on the stack, right under
the <headers> which we pop off on the first line.

*/ 

public void createTable(String name,String[]fldnames,
                        String[]fldtypes,boolean doReset){
//String createQ="CREATE TABLE COURSEBOOKS (SectionID TEXT, ItemCode TEXT);
  try{
    lg.logIt("createTable "+name+" with "+fldnames.length+" fields");
    int N=fldnames.length;
    String createStr="CREATE TABLE "+name+" (";
    if(N>0)createStr+=fldnames[0]+" "+fldtypes[0];
    for(int i=1;i<N;i++)createStr+=", "+fldnames[i]+" "+fldtypes[i];
    createStr+=")";
    lg.logIt("createStr="+createStr);
    try{theCreateTableStatement.execute(createStr);
    }catch(SQLException e){lg.logIt("createTable exception: "+e);}
      // this table may well already exist;
    if(doReset){
      String delStr="DELETE * FROM "+name+"";
      theCreateTableStatement.execute(delStr);
      }
   }catch(SQLException e){lg.logIt("createTable exception: "+e);}
}
public void createInserter(String name,String[]fldnames,String[]fldtypes)
    throws SAXException {
//String insertQ="INSERT INTO COURSEBOOKS VALUES (?,?)"
  try{
    int N=fldnames.length;
    String insertStr="INSERT INTO "+name+" VALUES (";
    if(N>0)insertStr+="?";
    for(int i=1;i<N;i++)insertStr+=", ?";
    insertStr+=")";
    lg.logIt("insertStr="+insertStr);
    theInsertPreparedStatement=theDBConnection.prepareStatement(insertStr);
   }catch(SQLException e){lg.logIt("createInserter exception: "+e);
     throw new SAXException("createInserter error",e);}
    // this table may well already exist.
}

  public EndHeadersHandler(){}
  public void doIt() throws SAXException {
    CallStackItem cSI=(CallStackItem)theCallStack.pop();
    lg.logIt("EndHeadersHandler doIt on "+cSI.name+"; kidnum="+cSI.kidNum);
    int N=cSI.kidNum;
    String[]header_names=new String[N];
    String[]header_types=new String[N];
    for(int i=N-1;i>=0;i--){
      Hashtable aL=(Hashtable)theValStack.pop();
      header_names[i]=(String)aL.get("name");
      header_types[i]=(String)aL.get("fieldType");
      }
    CallStackItem tableCSI=(CallStackItem)(theCallStack.peek());
    String tableName=tableCSI.name;
    Hashtable attrs=tableCSI.attrs;
    String reset=(null==attrs?null:(String)attrs.get("reset"));
    boolean doReset="true".equals(reset);
    createTable(tableName,header_names,header_types,doReset);
    createInserter(tableName,header_names,header_types);
    theEnv.put("header_names",header_names);
    theEnv.put("header_types",header_types);
    theEnv.put("tableName",tableName);
   }
}

public static void main(String[]args) throws Exception{
/* called as
    java MyNa.xml.Xml2DBTables DBSrc.xml
where DBSrc.xml is the template file. (samples provided as 
MyNa\xml\pbdata.xml and others)
*/
  MyNa.utils.Logger lg=new MyNa.utils.Logger();
  if(args.length!=1){
    System.out.println("Usage:");
    System.out.println(" java MyNa.xml.Xml2DBTables DBSrc.xml");
    System.out.println("where DBSrc.xml followed dbdata.dtd");
    return;}
  Xml2DBTables x2dbt=new Xml2DBTables(args[0]);
  x2dbt.doIt();
}

} // end Xml2DBTables class