一个解析xml文件遇到的问题

半岛铁盒里的猫 2014-11-12 04:48:01

最近照例程写了个xml文件解析到的程序解析结果有异常，调试了很久也没调试出来。功能就是把个标签里面的内容输出。代码如下：

MyContentHandler.java:

package com.example.xml;





import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.DefaultHandler;





import android.util.Log;





public class MyContentHandler extends DefaultHandler{

String tagName = null;

String linearLayout,textView,button ;



@Override

public void characters(char[] ch, int start, int length)

throws SAXException {





if(tagName.equals("TextView")){





textView = new String(ch,start,length);

Log.d("yinan", textView);

}



if(tagName.equals("Button")){





button = new String(ch,start,length);

Log.d("yinan", button);

}



}





@Override

public void endDocument() throws SAXException {

Log.d("yinan","end!");

}





@Override

public void endElement(String uri, String localName, String qName)

throws SAXException {

Log.d("yinan", "endElement:"+tagName);

if(tagName.equals("Button")){





this.print();

}



}





@Override

public void startDocument() throws SAXException {

Log.d("yinan","start!");

}





@Override

public void startElement(String uri, String localName, String qName,

Attributes attributes) throws SAXException {

tagName = localName;

Log.d("yinan", "start Element:"+tagName);

}



public void print(){

Log.d("yinan","TextView:");

Log.d("yinan",textView);

Log.d("yinan","Button:");

Log.d("yinan",button);

}



}









XMLActivity.java

package com.example.xml;





import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.StringReader;





import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParserFactory;





import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;





import android.app.Activity;

import android.os.Bundle;

import android.util.Log;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;





public class XMLActivity extends Activity {

Button button = null;



@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_xml);

button = (Button)findViewById(R.id.button);

button.setOnClickListener(new ParseButtonListener());

}





class ParseButtonListener implements OnClickListener{





@Override

public void onClick(View arg0) {

//Log.d("yinan", "!!!!!!!!!!!!!!!!!!"); 

try {

String str = getXml("/sdcard/main.xml");



//Log.d("yinan", "#############");



SAXParserFactory factory = SAXParserFactory.newInstance();



try {

XMLReader reader = factory.newSAXParser().getXMLReader();

reader.setContentHandler(new MyContentHandler());

reader.parse(new InputSource(new StringReader(str)));

} catch (SAXException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (ParserConfigurationException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}



} catch (IOException e) {



e.printStackTrace();

}



}



}



public String getXml(String s) throws IOException{

String str = null;

StringBuffer sb = new StringBuffer();

File file = new File(s);

if(!file.exists())

Log.d("yinan", "file does not exist!!");

FileInputStream input = new FileInputStream(file);

BufferedReader br = new BufferedReader(new InputStreamReader(input));



while((str = br.readLine()) != null){

sb.append(str);

}

input.close();

br.close();

return sb.toString();

}



@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.xml, menu);

return true;

}





}

被解析的xml文件如下：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout>

<TextView>android:layout_width="fill_parent" 

   android:layout_height="wrap_content" 

   android:text="@string/hello"

  </TextView>  

    

  <Button>	

    android:id="@+id/parseButton"

    android:layout_width="fill_parent" 

    android:layout_height="wrap_content" 

    android:text="开始解析XML"

   </Button>



</LinearLayout>