[Android]四种方式解析字符串----JSON、SAX、DOM、XML

当是练习吧，分别以JSON、SAX、DOM、XML(android.util.XML)来解析字符串。

个人感觉这四种方式的实现由难到易的顺序是：SAX→XML→DOM→JSON。

JSON解析的内容如下，文件名为devdiv.json，存于工程的assets目录下：

[xhtml] view plain copy

{
"code":"1",
"result":{
"title":"Devdiv移动开发社区",
"title_url":"http://www.devdiv.com/forum.php",
"development_forum_name":"开发讨论区",
"development_forum":[
{"name":"WindowsPhone论坛","url":"http://www.devdiv.com/forum-windows-phone-mobile-1.html"},
{"name":"Android论坛","url":"http://www.devdiv.com/forum-android-1.html"},
{"name":"iOS/iPhone论坛","url":"http://www.devdiv.com/forum-iphone-1.html"}
]
}
}

剩下三个解析内容如下，文件名为devdiv.xml，存于工程的assets目录下：

[xhtml] view plain copy

<root>
<title>Devdiv移动开发社区</title>
<body>开发讨论区</body>
<itemurl="http://www.devdiv.com/forum-windows-phone-mobile-1.html">WindowsPhone论坛</item>
<itemurl="http://www.devdiv.com/forum-android-1.html">Android论坛</item>
<itemurl="http://www.devdiv.com/forum-iphone-1.html">iOS/iPhone论坛</item>
</root>

本例子解析后显示效果：

对于DOM的解析，在SDK8及以上版本有两种方法。代码如下：

[java] view plain copy

packagelab.sodino.string;
importjava.io.IOException;
importjava.io.InputStream;
importjava.util.Vector;
importjavax.xml.parsers.DocumentBuilder;
importjavax.xml.parsers.DocumentBuilderFactory;
importjavax.xml.parsers.FactoryConfigurationError;
importjavax.xml.parsers.ParserConfigurationException;
importjavax.xml.parsers.SAXParser;
importjavax.xml.parsers.SAXParserFactory;
importorg.json.JSONArray;
importorg.json.JSONException;
importorg.json.JSONObject;
importorg.w3c.dom.Document;
importorg.w3c.dom.Element;
importorg.w3c.dom.Node;
importorg.w3c.dom.NodeList;
importorg.xml.sax.Attributes;
importorg.xml.sax.SAXException;
importorg.xml.sax.helpers.DefaultHandler;
importandroid.app.Activity;
importandroid.graphics.Typeface;
importandroid.os.Build;
importandroid.os.Bundle;
importandroid.text.SpannableString;
importandroid.text.Spanned;
importandroid.text.method.LinkMovementMethod;
importandroid.text.style.StyleSpan;
importandroid.text.style.URLSpan;
importandroid.util.Log;
importandroid.view.View;
importandroid.widget.Button;
importandroid.widget.TextView;
publicclassTextActextendsActivity{
publicstaticfinalStringTAG="ANDROID_LAB";
privateButtonbtnJSON;
privateButtonbtnSAX;
privateButtonbtnDOM;
privateButtonbtnXML;
privateBtnListenerbtnListener;
privateTextViewtxtInfo;
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btnListener=newBtnListener();
btnDOM=(Button)findViewById(R.id.btnDOM);
btnDOM.setOnClickListener(btnListener);
txtInfo=(TextView)findViewById(R.id.txtInfo);
}
privatevoidinflateTextViewByBean(Beanbean){
intspanCount=4;
int[]start=newint[spanCount];
int[]end=newint[spanCount];
StringBufferbuffer=newStringBuffer();
buffer.append(bean.type+"/n");
buffer.append(bean.title+"/n");
start[0]=buffer.length();
buffer.append(bean.development_forum_name+"/n");
end[0]=buffer.length();
for(inti=0;i<bean.vecName.size();i++){
start[i+1]=buffer.length();
buffer.append(bean.vecName.get(i)+"/n");
end[i+1]=buffer.length();
}
SpannableStringspannableString=newSpannableString(buffer.toString());
spannableString.setSpan(newStyleSpan(Typeface.ITALIC),start[0],end[0],
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
for(inti=0;i<bean.vecName.size();i++){
spannableString.setSpan(newURLSpan(bean.vecUrl.get(i)),start[i+1],end[i+1],
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
txtInfo.setText(spannableString);
txtInfo.setMovementMethod(LinkMovementMethod.getInstance());
}
classBtnListenerimplementsButton.OnClickListener{
publicvoidonClick(Viewview){
if(view==btnJSON){
showInfoFromJSON();
}elseif(view==btnSAX){
showInfoFromSAXParser();
}elseif(view==btnDOM){
showInfoFromDOM();
}elseif(view==btnXML){
showInfoFromXML();
}
}
}
publicvoidshowInfoFromJSON(){
Beanbean=newBean();
bean.type="InflatedbyJSON/n";
Stringcontent="";
InputStreamis=null;
try{
is=getAssets().open("devdiv.json");
byte[]data=newbyte[is.available()];
is.read(data);
content=newString(data);
Log.d(TAG,"content="+content);
JSONObjectjsonContent=newJSONObject(content);
intcode=jsonContent.getInt("code");
//假设默认code为1时才是正确的json数据。
if(code==1){
JSONObjectjsonResult=jsonContent.getJSONObject("result");
bean.title=jsonResult.getString("title");
bean.development_forum_name=jsonResult.getString("development_forum_name");
bean.vecName=newVector<String>();
bean.vecUrl=newVector<String>();
JSONArraydevArr=jsonResult.getJSONArray("development_forum");
Stringtmp="";
for(inti=0;i<devArr.length();i++){
JSONObjectobj=devArr.getJSONObject(i);
tmp=obj.getString("name");
bean.vecName.add(tmp);
tmp=obj.getString("url");
bean.vecUrl.add(tmp);
}
inflateTextViewByBean(bean);
}else{
Log.d(TAG,"Aerroroccurwhenparseajsonfile.");
}
}catch(IOExceptione){
e.printStackTrace();
}catch(JSONExceptione){
e.printStackTrace();
}finally{
try{
if(is!=null){
is.close();
}
}catch(IOExceptionie){
ie.printStackTrace();
}
}
}
publicvoidshowInfoFromXML(){
Beanbean=newBean();
bean.type="InflatedbyXML/n";
bean.vecName=newVector<String>();
bean.vecUrl=newVector<String>();
MyXMLHandlerxmlHandler=null;
InputStreamis=null;
xmlHandler=newMyXMLHandler(bean);
try{
is=getAssets().open("devdiv.xml");
//一句话就OK了。
android.util.Xml.parse(is,android.util.Xml.Encoding.UTF_8,xmlHandler);
}catch(IOExceptione){
e.printStackTrace();
}catch(SAXExceptione){
e.printStackTrace();
}finally{
try{
if(is!=null){
is.close();
}
}catch(IOExceptionie){
ie.printStackTrace();
}
}
inflateTextViewByBean(bean);
}
publicvoidshowInfoFromDOM(){
Beanbean=newBean();
bean.type="InflatedbyDOM/n";
bean.vecName=newVector<String>();
bean.vecUrl=newVector<String>();
InputStreamis=null;
DocumentBuilderFactorydomFactory=DocumentBuilderFactory.newInstance();
try{
is=getAssets().open("devdiv.xml");
NodeListlist=null;
DocumentBuilderdomBuilder=domFactory.newDocumentBuilder();
Documentdoc=domBuilder.parse(is);
//获取根目录
ElementrootElement=doc.getDocumentElement();
//输出[rootElement=root]
Log.d(TAG,"rootElement="+rootElement.getNodeName());
list=rootElement.getElementsByTagName("title");
if(Integer.parseInt(Build.VERSION.SDK)>=8){
//在已提前获只有一个title的情况下直接去取list.item(0)
bean.title=list.item(0).getTextContent();
//在已提前获只有一个body的情况下直接去取list.item(0)
list=rootElement.getElementsByTagName("body");
bean.development_forum_name=list.item(0).getTextContent();
//多个item的读取情形
list=rootElement.getElementsByTagName("item");
for(inti=0;i<list.getLength();i++){
Nodenode=list.item(i);
bean.vecUrl.add(node.getAttributes().item(0).getTextContent());
bean.vecName.add(node.getTextContent());
}
}else{
//在已提前获只有一个title的情况下直接去取list.item(0)
bean.title=list.item(0).getFirstChild().getNodeValue();
//在已提前获只有一个body的情况下直接去取list.item(0)
list=rootElement.getElementsByTagName("body");
bean.development_forum_name=list.item(0).getFirstChild().getNodeValue();
//多个item的读取情形
list=rootElement.getElementsByTagName("item");
for(inti=0;i<list.getLength();i++){
Nodenode=list.item(i);
bean.vecUrl.add(node.getAttributes().getNamedItem("url").getNodeValue());
bean.vecName.add(node.getFirstChild().getNodeValue());
}
}
}catch(ParserConfigurationExceptione){
e.printStackTrace();
}catch(IOExceptione){
e.printStackTrace();
}catch(SAXExceptione){
e.printStackTrace();
}finally{
try{
if(is!=null){
is.close();
}
}catch(IOExceptionie){
ie.printStackTrace();
}
}
inflateTextViewByBean(bean);
}
publicvoidshowInfoFromSAXParser(){
Beanbean=newBean();
bean.vecName=newVector<String>();
bean.vecUrl=newVector<String>();
bean.type="InflatedbySAXParser/n";
InputStreamis=null;
SAXParserparser=null;
MyXMLHandlerxmlHandler=null;
try{
parser=SAXParserFactory.newInstance().newSAXParser();
xmlHandler=newMyXMLHandler(bean);
is=getAssets().open("devdiv.xml");
parser.parse(is,xmlHandler);
inflateTextViewByBean(bean);
}catch(IOExceptionie){
ie.printStackTrace();
}catch(ParserConfigurationExceptione){
e.printStackTrace();
}catch(SAXExceptione){
e.printStackTrace();
}catch(FactoryConfigurationErrore){
e.printStackTrace();
}finally{
try{
if(is!=null){
is.close();
}
}catch(IOExceptionie){
ie.printStackTrace();
}
}
}
classMyXMLHandlerextendsDefaultHandler{
Beanbean;
StringcurrentElement;
publicMyXMLHandler(Beanbean){
MyXMLHandler.this.bean=bean;
}
publicvoidstartDocument()throwsSAXException{
Log.d(TAG,"MyXMLHandlerstartDocument");
}
publicvoidendDocument()throwsSAXException{
Log.d(TAG,"MyXMLHandlerendDocument");
}
publicvoidstartElement(Stringuri,StringlocalName,StringqName,Attributesatts)
throwsSAXException{
//Log.d(TAG,"MyXMLHandlerstartElement");
currentElement=localName;
if(localName.equals("item")){
if(atts!=null){
for(inti=0;i<atts.getLength();i++){
//本例中atts.getLength()值为1
bean.vecUrl.add(atts.getValue(i));
Log.d(TAG,"addurl["+atts.getValue(i)+"]");
}
}
}
}
publicvoidcharacters(char[]ch,intstart,intlength)throwsSAXException{
Stringstr=newString(ch,start,length);
//Log.d(TAG,"MyXMLHandlercharactersstart="+start+"len="+
//length+"str["+str
//+"]");
if(currentElement!=null){
Stringtmp=newString(ch,start,length);
if(currentElement.equals("title")){
bean.title=tmp;
}elseif(currentElement.equals("body")){
bean.development_forum_name=tmp;
}elseif(currentElement.equals("item")){
bean.vecName.add(tmp);
Log.d(TAG,"addname["+tmp+"]");
}
}
}
publicvoidendElement(Stringuri,StringlocalName,StringqName)throwsSAXException{
Log.d(TAG,"MyXMLHandlerendDocument");
currentElement=null;
}
}
classBean{
Stringtype;
Stringtitle;
Stringdevelopment_forum_name;
Vector<String>vecName;
Vector<String>vecUrl;
}
}

本文内容归CSDN博客博主Sodino所有

转载请注明出处:http://blog.csdn.net/sodino/archive/2011/04/06/6305949.aspx

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