HttpURLConnection
activity_main.xml
<!--手機(jī)界面有限，需要這個(gè)控件來滾動(dòng)展示內(nèi)容-->
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/textview0"/>
</ScrollView>
MainActivity.java
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
//實(shí)例化一個(gè)要訪問的地址對(duì)象
URL url = new URL("HTTP://360.net");
//打開鏈接到url地址的連接通道应民，并強(qiáng)制轉(zhuǎn)化成Http協(xié)議的連接類型
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
//GET請(qǐng)求
httpURLConnection.setRequestMethod("GET");
//10s連接超時(shí)
httpURLConnection.setConnectTimeout(10000);
//從連接到的資源上讀取時(shí)間不能超過5s
httpURLConnection.setReadTimeout(5000);
//從遠(yuǎn)程連接的地址上獲取資源數(shù)據(jù)犁功，流進(jìn)到本地
//BufferedReader: Reads text from a character-input stream
InputStream in = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in));
//從BufferedReader對(duì)象中獲取文本數(shù)據(jù)
StringBuilder stringbuilder = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null){
stringbuilder.append(line);
}
TextView text = (TextView)findViewById(R.id.textview0);
text.setText(stringbuilder.toString());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
android.os.NetworkOnMainThreadException
官方：
The exception that is thrown when an application attempts to perform a networking operation on its main thread.
主線程內(nèi)不能進(jìn)行網(wǎng)絡(luò)請(qǐng)求（早期版本還是可以的），嘗試開啟子線程進(jìn)行這個(gè)工作
public class MainActivity extends Activity {
//實(shí)例化一個(gè)Handler對(duì)象深纲，并重寫他的處理消息的方法劫灶，來處理我們發(fā)送的消息
public Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch (msg.what){
case 1:{
String string = (String) msg.obj;
TextView textview = (TextView)findViewById(R.id.textview0);
textview.setText(string);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//開啟子線程進(jìn)行費(fèi)時(shí)工作
new Thread(new Runnable() {
@Override
public void run() {
try {
//實(shí)例化一個(gè)要訪問的地址對(duì)象
URL url = new URL("HTTP://360.net");
//打開鏈接到url地址的連接通道划址，并強(qiáng)制轉(zhuǎn)化成Http協(xié)議的連接類型
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
//GET請(qǐng)求
httpURLConnection.setRequestMethod("GET");
//10s連接超時(shí)
httpURLConnection.setConnectTimeout(10000);
//從連接到的資源上讀取時(shí)間不能超過5s
httpURLConnection.setReadTimeout(5000);
//從遠(yuǎn)程連接的地址上獲取資源數(shù)據(jù)扔嵌，流進(jìn)到本地
//BufferedReader: Reads text from a character-input stream
InputStream in = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in));
//從BufferedReader對(duì)象中獲取文本數(shù)據(jù)
StringBuilder stringbuilder = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null){
stringbuilder.append(line);
}
//消息對(duì)象
Message message = new Message();
//消息標(biāo)識(shí)符限府，方便接受者接收指定消息
message.what = 1;
//an arbitrary（任意） object to send to the recipient（接受者）.
message.obj = stringbuilder.toString();
handler.sendMessage(message);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
}
HttpClient(Interface)
HttpClient是 Apache 提供的 HTTP 網(wǎng)絡(luò)訪問接口，從一開始的時(shí)候就被引入到了 Android
API 中
- GET請(qǐng)求
build.gradle
android {
//主要在android字段下添加這一句
useLibrary 'org.apache.http.legacy'
.....
MainActivity.java
public class MainActivity extends Activity {
//實(shí)例化一個(gè)Handler對(duì)象痢缎，并重寫他的處理消息的方法胁勺，來處理我們發(fā)送的消息
public Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch (msg.what){
case 1:{
String string = (String) msg.obj;
TextView textview = (TextView)findViewById(R.id.textview0);
textview.setText(string);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//開啟子線程進(jìn)行費(fèi)時(shí)工作
new Thread(new Runnable() {
@Override
public void run() {
//Creates a new HTTP client
HttpClient httpclient = new DefaultHttpClient();
//實(shí)例化一個(gè)GET 請(qǐng)求對(duì)象
HttpGet getRequest = new HttpGet("http://www.so.com");
//客戶端發(fā)起這個(gè)GET請(qǐng)求對(duì)象
try {
httpclient.execute(getRequest);
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
}
- POST請(qǐng)求
比GET請(qǐng)求只是多有一些參數(shù)數(shù)據(jù)
MainActivity.java
public class MainActivity extends Activity {
//實(shí)例化一個(gè)Handler對(duì)象，并重寫他的處理消息的方法独旷，來處理我們發(fā)送的消息
public Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch (msg.what){
case 1:{
String string = (String) msg.obj;
TextView textview = (TextView)findViewById(R.id.textview0);
textview.setText(string);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//開啟子線程進(jìn)行費(fèi)時(shí)工作
new Thread(new Runnable() {
@Override
public void run() {
//Creates a new HTTP client
HttpClient httpclient = new DefaultHttpClient();
//實(shí)例化一個(gè)POST 請(qǐng)求對(duì)象
HttpPost request = new HttpPost("https://mail.qq.com/cgi-bin/loginpage?autologin=n");
//NameValuePair是一個(gè)接口署穗，提供了獲取鍵值對(duì)數(shù)據(jù)的功能
ArrayList<NameValuePair> params = new ArrayList<NameValuePair>();
//獲取鍵值數(shù)據(jù),擁有NameValuePair的類型
params.add(new BasicNameValuePair("username","password"));
try {
//對(duì)參數(shù)數(shù)據(jù)進(jìn)行URL編碼
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params, "utf-8");
//將編碼后的數(shù)據(jù)實(shí)體放入請(qǐng)求中
request.setEntity(entity);
//發(fā)送請(qǐng)求,獲取瀏覽器響應(yīng)
HttpResponse httpresponse = (HttpResponse) httpclient.execute(request);
//查看返回的狀態(tài)碼
if (httpresponse.getStatusLine().getStatusCode() == 200){
Log.e("statuscode", "200");
// Toast.makeText(getApplicationContext(), "status code :200 ",Toast.LENGTH_LONG);
}else {
int codenumber = httpresponse.getStatusLine().getStatusCode();
// Toast.makeText(MainActivity.this, "status code :" + String.valueOf(codenumber),Toast.LENGTH_LONG);
Log.e("statuscode", String.valueOf(codenumber));
}
//將網(wǎng)站返回的數(shù)據(jù)，又消息傳遞給Handler
String responsecontent = EntityUtils.toString(httpresponse.getEntity());
Message message = new Message();
message.what = 1;
message.obj = responsecontent;
handler.sendMessage(message);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
}
上面代碼中注釋了2句Toast嵌洼，因?yàn)闀?huì)報(bào)錯(cuò)
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()案疲，很明顯這是因?yàn)檫@個(gè)Toast內(nèi)部應(yīng)該創(chuàng)建handler來執(zhí)行的
XML格式
千萬不要少了eventType = xmlparse.next();這句里的next()方法，來推動(dòng)解析往下進(jìn)行
public class MainActivity extends Activity {
//實(shí)例化一個(gè)Handler對(duì)象麻养，并重寫他的處理消息的方法褐啡，來處理我們發(fā)送的消息
public Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch (msg.what){
case 1:{
Toast.makeText(getApplicationContext(), "status code :200 ",Toast.LENGTH_LONG);
TextView textView = (TextView)findViewById(R.id.textview0);
textView.setText((String)msg.obj);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//開啟子線程進(jìn)行費(fèi)時(shí)工作
new Thread(new Runnable() {
@Override
public void run() {
//Creates a new HTTP client
HttpClient httpclient = new DefaultHttpClient();
//實(shí)例化一個(gè)POST 請(qǐng)求對(duì)象
HttpGet request = new HttpGet("http://10.91.35.22/aaa.xml");
//NameValuePair是一個(gè)接口，提供了獲取鍵值對(duì)數(shù)據(jù)的功能
try {
//發(fā)送請(qǐng)求,獲取瀏覽器響應(yīng)
HttpResponse httpresponse = (HttpResponse) httpclient.execute(request);
//查看返回的狀態(tài)碼
if (httpresponse.getStatusLine().getStatusCode() == 200){
Log.e("statuscode", "200");
// Toast.makeText(getApplicationContext(), "status code :200 ",Toast.LENGTH_LONG);
}else {
int codenumber = httpresponse.getStatusLine().getStatusCode();
// Toast.makeText(MainActivity.this, "status code :" + String.valueOf(codenumber),Toast.LENGTH_LONG);
Log.e("statuscode", String.valueOf(codenumber));
}
//將網(wǎng)站返回的數(shù)據(jù)鳖昌，又消息傳遞給Handler
String responsecontent = EntityUtils.toString(httpresponse.getEntity());
Message message = new Message();
message.what = 1;
message.obj = responsecontent;
handler.sendMessage(message);
xmlparse(responsecontent);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
public void xmlparse(String response){
//這個(gè)對(duì)象使用來創(chuàng)建xml解析器
try {
XmlPullParserFactory xmlfactory = XmlPullParserFactory.newInstance();
//XML解析器
XmlPullParser xmlparse = xmlfactory.newPullParser();
//給解析器傳入響應(yīng)數(shù)據(jù)流
xmlparse.setInput(new StringReader(response));
//返回當(dāng)前事件的類型
int eventType = xmlparse.getEventType();
//標(biāo)簽
String id = "";
String name = "";
String version = "";
//END_DOCUMENT類型表示xml文件邏輯結(jié)束
//也就是只要xml沒有解析結(jié)束备畦，繼續(xù)執(zhí)行
while(eventType != XmlPullParser.END_DOCUMENT) {
//節(jié)點(diǎn)名稱
String nodename = xmlparse.getName();
//開始解析某個(gè)節(jié)點(diǎn)
switch (eventType) {
//開始讀取標(biāo)簽
case XmlPullParser.START_TAG: {
if ("id".equals(nodename)) {
id = xmlparse.nextText();
Log.e("[+] id: ",id);
} else if ("name".equals(nodename)) {
name = xmlparse.nextText();
Log.e("[+] name: ",name);
} else if ("version".equals(nodename)) {
version = xmlparse.nextText();
Log.e("[+] version: ",version);
}
break;
}
case XmlPullParser.END_TAG:{
Log.e("xml", "解析結(jié)束");
break;
}
default:
break;
}
//解析下一個(gè)節(jié)點(diǎn)
eventType = xmlparse.next();
}
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
SAX解析
用到了一個(gè)類org.xml.sax.helpers.DefaultHandler
重寫這五個(gè)方法來處理節(jié)點(diǎn)的數(shù)據(jù)
defaultHandler.java
public class defaultHandler extends org.xml.sax.helpers.DefaultHandler{
private StringBuilder id;
private StringBuilder name;
private StringBuilder version;
private String elementName;
@Override
//開始xml文檔解析
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 {
Log.e("[+] ", "開始解析節(jié)點(diǎn)");
//節(jié)點(diǎn)名稱
elementName = localName;
}
@Override
//接收節(jié)點(diǎn)里數(shù)據(jù)的通知
public void characters(char[] ch, int start, int length) throws SAXException {
Log.e("[+] ", "處理節(jié)點(diǎn)里的數(shù)據(jù)");
if("id".equals(elementName)){
id.append(ch, start, length);
}else if("name".equals(elementName)){
name.append(ch, start, length);
}else if("version".equals(elementName)){
version.append(ch, start, length);
}
}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
Log.e("[+] ", "處理節(jié)點(diǎn)結(jié)束");
}
@Override
public void endDocument() throws SAXException {
Log.e("[+] id", "id is"+ id.toString());
Log.e("[+] name", "name is"+ name.toString());
Log.e("[+] version", "version is"+ version.toString());
Log.e("[+] ", "xml文件解析完畢");
//釋放緩沖區(qū)
id.setLength(0);
name.setLength(0);
version.setLength(0);
}
}
MainActivity.java
public class MainActivity extends Activity {
//實(shí)例化一個(gè)Handler對(duì)象，并重寫他的處理消息的方法许昨，來處理我們發(fā)送的消息
public Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch (msg.what){
case 1:{
Toast.makeText(getApplicationContext(), "status code :200 ",Toast.LENGTH_LONG);
TextView textView = (TextView)findViewById(R.id.textview0);
textView.setText((String)msg.obj);
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//開啟子線程進(jìn)行費(fèi)時(shí)工作
new Thread(new Runnable() {
@Override
public void run() {
//Creates a new HTTP client
HttpClient httpclient = new DefaultHttpClient();
//實(shí)例化一個(gè)POST 請(qǐng)求對(duì)象
HttpGet request = new HttpGet("http://10.91.35.22/aaa.xml");
//NameValuePair是一個(gè)接口懂盐，提供了獲取鍵值對(duì)數(shù)據(jù)的功能
try {
//發(fā)送請(qǐng)求,獲取瀏覽器響應(yīng)
HttpResponse httpresponse = (HttpResponse) httpclient.execute(request);
//查看返回的狀態(tài)碼
if (httpresponse.getStatusLine().getStatusCode() == 200){
Log.e("statuscode", "200");
// Toast.makeText(getApplicationContext(), "status code :200 ",Toast.LENGTH_LONG);
}else {
int codenumber = httpresponse.getStatusLine().getStatusCode();
// Toast.makeText(MainActivity.this, "status code :" + String.valueOf(codenumber),Toast.LENGTH_LONG);
Log.e("statuscode", String.valueOf(codenumber));
}
//將網(wǎng)站返回的數(shù)據(jù)，又消息傳遞給Handler
String responsecontent = EntityUtils.toString(httpresponse.getEntity());
Message message = new Message();
message.what = 1;
message.obj = responsecontent;
handler.sendMessage(message);
xmlparse(responsecontent);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
public void xmlparse(String response){
//這個(gè)對(duì)象使用來創(chuàng)建xml解析器
try {
SAXParserFactory saxfactory = SAXParserFactory.newInstance();
//XML解析器
SAXParser saxparse = saxfactory.newSAXParser();
//開始解析,傳入?yún)?shù)车要，和解析方式
saxparse.parse(new InputSource(new StringReader(response)), new defaultHandler());
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
JSON解析
``
出現(xiàn)一個(gè)小問題就是android4.0之后，json檢測utf bom頭
用BOM: Zero Width No-Break Space來表明是UTF編碼崭倘，看下面的代碼翼岁，是需要檢測編碼的
public JSONTokener(String in) {
// consume an optional byte order mark (BOM) if it exists
if (in != null && in.startsWith("\ufeff")) {
in = in.substring(1);
}
this.in = in;
}
添加bom頭，繼續(xù)報(bào)錯(cuò)
...type org.json.JSONObject cannot be converted to JSONArray
response = "\ufeff"+ response;
根據(jù) 相似問題org.json.JSONObject cannot be converted to JSONArray in android司光，知道從json對(duì)象中先獲取json數(shù)組琅坡，改成如下代碼，還是報(bào)錯(cuò)残家，
info of type org.json.JSONObject cannot be converted to JSONArray
JSONObject jsondata = new JSONObject(response);
JSONArray jsonArray = jsondata.getJSONArray("info");
for (int i = 0; i<jsonArray.length(); i++){
JSONObject jsonobj = jsonArray.getJSONObject(i);
Log.e("獲取的json數(shù)據(jù)：info",(String) jsonobj.get("name"));
}
跟蹤源代碼運(yùn)行榆俺，終于發(fā)現(xiàn)，這里JSON數(shù)據(jù)有5個(gè)字段坞淮，鍵值info對(duì)應(yīng)的值還是一個(gè)JSON對(duì)象（可以將大括號(hào){}看成一個(gè)JSON對(duì)象)
2018-10-09_202029.png
2018-10-09_202029.png
繼續(xù)向下打開茴晋，發(fā)現(xiàn)JSONArray對(duì)象指的是鍵值對(duì)中的值為一個(gè)列表，所以代碼需要多解析幾步回窘，上面哪些錯(cuò)誤是不用理會(huì)的
2018-10-09_202820.png
public void jsonParse(String response) throws JSONException {
JSONObject jsondata = new JSONObject(response);
JSONArray jsonArray = jsondata.getJSONObject("info").getJSONArray("builtin_modules");
for (int i = 0; i<jsonArray.length(); i++){
Log.e("獲取的json數(shù)據(jù)：info",(String) jsonArray.get(i));
}
}
2018-10-09_203404.png
GSON解析Google提供的第三方庫
1诺擅、先下載GJSON的jar包下載地址
2、將jar包放入libs目錄下啡直，然后右鍵這個(gè)jar包烁涌，選擇add as libary選項(xiàng)苍碟，即可
2018-10-09_205314.png
3、代碼
你真的會(huì)用Gson嗎?Gson使用指南（一）
person.java
public class person {
private String name;
private int age;
private String ads;
//省略setter撮执、getter微峰、constructor
}
MainActivity.java
//一個(gè)擁有名字和年齡的對(duì)象
person p1 = new person("kingkary", 56);
//獲取一個(gè)Gson對(duì)象
Gson gson = new Gson();
//將這個(gè)對(duì)象中的數(shù)據(jù)轉(zhuǎn)成json類型
Log.e("JSON數(shù)據(jù)",gson.toJson(p1));
2018-10-09_214814.png
