java读取xml配置文件(sax)

xml文件:Conn.xml
<?xml version="1.0" encoding="utf-8"?>
<reportenv>
<datasource>
<host>127.0.0.1</host>
<database>test</database>
<username>root</username>
<password>******</password>
</datasource>
</reportenv>

读取xml文件:ReadConfigXml.java
package classes;

import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.SAXException;
import java.util.Properties;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.net.URL;

class ConfigParser extends DefaultHandler {

////定义一个Properties 用来存放属性值
private Properties props;

private String currentSet;
private String currentName;
private StringBuffer currentValue = new StringBuffer();

//构建器初始化props
public ConfigParser() {

this.props = new Properties();
}

public Properties getProps() {
return this.props;
}

//定义开始解析元素的方法. 这里是将<xxx>中的名称xxx提取出来.
public void startElement(String uri, String localName, String qName, Attributes attributes)
throws SAXException {
currentValue.delete(0, currentValue.length());
this.currentName =qName;
}

//这里是将<xxx></xxx>之间的值加入到currentValue
public void characters(char[] ch, int start, int length) throws SAXException {
currentValue.append(ch, start, length);
}

//在遇到</xxx>结束后,将之前的名称和值一一对应保存在props中
public void endElement(String uri, String localName, String qName) throws SAXException {
props.put(qName.toLowerCase(), currentValue.toString().trim());
}

}

   class ParseXML{
//定义一个Properties 用来存放属性值
private Properties props;

public Properties getProps() {
return this.props;
}

public void parse(String filename) throws Exception {
//将我们的解析器对象化
ConfigParser handler = new ConfigParser();
//获取SAX工厂对象
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setNamespaceAware(false);
factory.setValidating(false);
//获取SAX解析
SAXParser parser = factory.newSAXParser();
try{
//将解析器和解析对象xml联系起来,开始解析
parser.parse(filename, handler);
//获取解析成功后的属性
props = handler.getProps();
}finally{
factory=null;
parser=null;
handler=null;
}
}
}

public class ReadConfigXml
{
private Properties props;

public ReadConfigXml(String url){
ParseXML myRead = new ParseXML();
try {
myRead.parse(url);
props = new Properties();
props = myRead.getProps();
} catch (Exception e) {
e.printStackTrace();
}
}

  public String getHost(){
    return props.getProperty("host");
    }
  public String getDataBase(){
    return props.getProperty("database");
    }
  public String getUserName(){
return props.getProperty("username");
}
  public String getPassWord(){
return props.getProperty("password");
}

}

连接数据库:Conn.java
//--------------数据库连接---------------------
class Conn{
  private Connection conn = null;
  private Statement stmt = null;
  public static void main(String args[]){
    try{      //加载驱动
      Class.forName("com.mysql.jdbc.Driver").newInstance();
      System.out.println("Success loading Mysql Driver!");
    }catch(Exception e){
      System.out.println("Error loading Mysql Driver!");
    }
    ReadConfigXml r = new ReadConfigXml("Conn.xml");    //读取xml文件中数据库相关信息
    try{      //连接数据库
      conn = DriverManager.getConnection("jdbc:mysql://"+r.getHost()+"/"+r.getDataBase()+"?user="+r.getUserName()+"&password="+r.getPassWord()+"&characterEncoding=gb2312");
      System.out.println("Success connect Mysql Database!");  
    }catch(SQLException e){
      System.out.println(e.getMessage());
    }
  }
}