简单的网络技术及数据解析

网络技术：

1 WebView访问网络:

public class MainActivity extends Activity {

private WebView webView;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

webView = (WebView)findViewById(R.id.web_view);
//让WebView支持javaScript脚本
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
webView.loadUrl("http://192.168.1.105:8080/");

}
}

加个权限：
<uses-permission android:name="android.permission.INTERNET"/>

2 开启线程发送网络请求

两种方式:
1 HttpClient
private void sendRequesWithHttpClient() {

new Thread(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub

try {

HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(
"http://www.360.com");
HttpResponse httpResponse = httpClient.execute(httpGet);

if (httpResponse.getStatusLine().getStatusCode() == 200) {

HttpEntity httpEntity = httpResponse.getEntity();

String response = EntityUtils.toString(httpEntity,"utf-8");

//把结果传递到message
Message message = new Message();
message.what = SHOW_RESPONSE;

message.obj = response.toString();
//发送message到handler
handler.sendMessage(message);

}

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}

}).start();
}

2 HttpURLConnection

private void sendRequestWithHttpURLConnection() {
//
new Thread(new Runnable() {
@Override
public void run() {
HttpURLConnection connection = null;
try {
URL url = new URL("http://www.360.com");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
connection.setDoInput(true);
connection.setDoOutput(true);
InputStream in = connection.getInputStream();
// 高效读入流
BufferedReader reader = new BufferedReader(
new InputStreamReader(in));
StringBuilder response = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
response.append(line);
}
Message message = new Message();
message.what = SHOW_RESPONSE;
// 发送数据
message.obj = response.toString();
handler.sendMessage(message);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
}
}
}).start();
}

1 2 都要结合一个Handler 即

private Handler handler = new Handler(){
public void handleMessage(Message msg){
switch (msg.what) {
case SHOW_RESPONSE:
String response = (String)msg.obj;
//在这里进行Ui操作，把结果显示到TextView中
text.setText(response);
break;

default:
break;
}
}
};

Url的链接不要用www.baidu.com

网络传输数据的解析：XML  和    JSON

XML：
第一种方式Pull解析

第二种SAX 首先要新建一个类继承DefaultHandler

public class ContentHandler extends DefaultHandler {

private String nodeName ;
private StringBuilder id;
private StringBuilder name;
private StringBuilder version;

@Override
public void startDocument() throws SAXException{
id = new StringBuilder();
name = new StringBuilder();
version = new StringBuilder();
}

@Override
public void startElement(String uri,String localName,String qName,
Attributes attributes) throws SAXException{
//记录当前的结点名
nodeName = localName;
}

@Override
public void characters(char[] ch,int start,int length) throws SAXException{
//根据当前的结点名判断将内容添加到不同的StringBuilder对象中
if("id".equals(nodeName)){
id.append(ch,start,length);
}else if("name".equals(nodeName)){
name.append(ch,start,length);
}else if("version".equals(nodeName)){
version.append(ch,start,length);
}
}

@Override
public void endElement(String uri,String localName,String qName) throws SAXException{

if("app".equals(localName)){
Log.d("ContentHandler", "id is "+id.toString().trim());
Log.d("ContentHandler", "name is "+name.toString().trim());
Log.d("ContentHandler", "version is "+version.toString().trim());

//最后把StringBuilder清空,否则会影响下一次的读取
id.setLength(0);
name.setLength(0);
version.setLength(0);
}
}

@Override
public void endDocument() throws SAXException{

}
}

然后再到MianActivity调用

JSON格式：
解析方式：
1 JSONObject
//json的JSONObject解析
private void parseJSONWithJSONObject(String jsondata){

try {
JSONArray jsonArray = new JSONArray(jsondata);

for(int i=0;i<jsonArray.length();i++){
JSONObject jsonObject = jsonArray.getJSONObject(i);

String id  = jsonObject.getString("id");
String name = jsonObject.getString("name");
String version = jsonObject.getString("version");

Log.d("id", "id is "+id);
Log.d("name", "name is "+name);
Log.d("version", "version is "+version);

}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}

2 GSON

//json的GSON的解析方式---google开源
//GSON能够把数据自动映射成一个对象,省了代码量
//所以在这里我先新建一个App类
//前提是要有GSON.jar包
private void parseJSONWithGSON(String jsondata){
Gson gson = new Gson();
List<App> applist = gson.fromJson(jsondata, new TypeToken<List<App>>(){}.getType());

for(App app:applist){
Log.d("MainActivity", "id is "+app.getId());
Log.d("MainActivity", "name is "+app.getName());
Log.d("MainActivity", "version is "+app.getVersion());
}
}

然后再到MainActivity调用

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);

}

private void sendRequesWithHttpClient() {
new Thread(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub

try {

HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(
"http://localhost:8080/Hello/data.xml");
HttpResponse httpResponse = httpClient.execute(httpGet);

if (httpResponse.getStatusLine().getStatusCode() == 200) {
HttpEntity httpEntity = httpResponse.getEntity();

String response = EntityUtils.toString(httpEntity);

parseXMLWithPull(response);

}

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}

}).start();
}

//SAX解析XML方法,与Pull解析的区别就是层次清晰
//要新建一个ContentHandler extends DefaultHander{
//重写五个方法
//}
private void parseXMLWithSAX(String xmldata){
try {
SAXParserFactory factory = SAXParserFactory.newInstance();

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

ContentHandler handler = new ContentHandler();

xmlReader.setContentHandler(handler);

//开始解析
xmlReader.parse(new InputSource(new StringReader(xmldata)));
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}

private void parseXMLWithPull(String xmldata) {
// TODO Auto-generated method stub
try {
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();

XmlPullParser xmlPullParser = factory.newPullParser();

xmlPullParser.setInput(new StringReader(xmldata));

int eventType = xmlPullParser.getEventType();

String id = "";
String name = "";
String version = "";

while (eventType != XmlPullParser.END_DOCUMENT) {
String nodeName = xmlPullParser.getName();

switch (eventType) {
case XmlPullParser.START_TAG: {
if ("id".equals(nodeName)) {
id = xmlPullParser.nextText();

}
if ("name".equals(nodeName)) {
id = xmlPullParser.nextText();

}
if ("version".equals(nodeName)) {
id = xmlPullParser.nextText();

}
break;

}
case XmlPullParser.END_TAG: {
if ("app".equals(nodeName)) {
Log.d("MainActivity", "id is " + id);
Log.d("MainActivity", "name is " + name);
Log.d("MainActivity", "version is " + version);
}
break;
}
default:
break;
}
eventType = xmlPullParser.next();
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}

注意：以上数据的解析全部要以本电脑创建本地服务器并在wenapp目录下新建.xml
和.json 文件，同时保证在公网的情况下（即android端和电脑端同一个网络）进行访问
否则则访问不到

同时也别忘了添加权限