【概述】最常用的两种网络请求类型：GET和POST。案例使用GET请求远程数据。
远程地址：http://www.***.com/data/type=3&cid=1,要获取的数据如下：
{"status":1,"data":{"title":"Tony\u8001\u5e08\u804ashell\u2014\u2014\u73af\u5883\u53d8\u91cf\u914d\u7f6e\u6587\u4ef6","author":"Tony","content":"\u672c\u8bfe\u7a0b\u662f\u300aTony\u8001\u5e08\u804ashell\u300b\u7cfb\u5217\u8bfe\u7a0b\u7684\u7b2c\u4e09\u7bc7\uff0c\u4e3a\u4f60\u5e26\u6765\u5e38\u7528\u7684\u73af\u5883\u53d8\u91cf\u914d\u7f6e\u6587\u4ef6\u7684\u4f7f\u7528\u3002"},"msg":"\u6210\u529f"}一、步骤：
//1实例化一个url对象
//2获取httpUrlConnection对象
//3设置请求连接属性
//4获取响应码，判断是否连接成功
//5读取输入流并解析step1:实例化一个URL对象
URL url=new URL("http://www.***.com/data/type=3&cid=1");//step1step2:获取httpUrlConnection对象
HttpURLConnection coon= (HttpURLConnection) url.openConnection();//step2step3:设置请求连接的属性
coon.setRequestMethod("GET");//step3step4:获取响应码，判断是否连接成功
if(coon.getResponseCode()==200){.....do something....}step5:获取输入流并解析
InputStream in=coon.getInputStream();
byte[] b=new byte[1024*512];
int len=0;
//建立缓存流，保存所读取的字节数组
ByteArrayOutputStream baos =new ByteArrayOutputStream();
while ((len=in.read(b))>-1){
baos.write(b,0,len);
}
String msg=baos.toString();
Log.e("TAG",msg);
//json数据的解析
JSONObject obj=new JSONObject(msg);
int status=obj.getInt("status");
String msg2=obj.getString("msg");
Log.e("TAG",status+" "+msg2);
JSONObject data=obj.getJSONObject("data");
String title=data.getString("title");
String author=data.getString("author");
String content=data.getString("content");二、出现的问题
①发起的http请求不能在主线程中
解决办法：创建新线程
new Thread(){
@Override
public void run() {
super.run();//△
}
}将请求代码粘贴到run中，代码如下：
new Thread(){
@Override
public void run() {
try {
URL url=new URL("http://www.***.com/data/type=3&cid=1");//step1
HttpURLConnection coon= (HttpURLConnection) url.openConnection();//step2
coon.setRequestMethod("GET");//step3
coon.setReadTimeout(6000);
if(coon.getResponseCode()==200){//step4
//获取输入流
InputStream in=coon.getInputStream();
byte[] b=new byte[1024*512];
int len=0;
//建立缓存流，保存所读取的字节数组
ByteArrayOutputStream baos =new ByteArrayOutputStream();
while ((len=in.read(b))>-1){
baos.write(b,0,len);
}
String msg=baos.toString();
Log.e("TAG",msg);
//json数据的解析
JSONObject obj=new JSONObject(msg);
int status=obj.getInt("status");
String msg2=obj.getString("msg");
Log.e("TAG",status+" "+msg2);
JSONObject data=obj.getJSONObject("data");
String title=data.getString("title");
String author=data.getString("author");
String content=data.getString("content");
Log.e("TAG","标题："+title+"，作者："+author+"，内容："+content);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
}.start();②JSON数据的解析
应注意判断对象是String int or Jsonobject，应用对应的方法去解析。
//json数据的解析
JSONObject obj=new JSONObject(msg);
int status=obj.getInt("status");
String msg2=obj.getString("msg");
Log.e("TAG",status+" "+msg2);
JSONObject data=obj.getJSONObject("data");
String title=data.getString("title");
String author=data.getString("author");
String content=data.getString("content");
Log.e("TAG","标题："+title+"，作者："+author+"，内容："+content);③子线程不能修改主线程控件内容
nameView.setText(title)
在子线程中执行修改主线程textView的数据时，出现以下报错
找到73f,代码是：
nameView.setText(title);
authorView.setText(author);
contentView.setText(content);这是因为子线程中进行了对主线程中创建的控件textView的内容的修改而报错。
解决办法：将操作权转交给主线程，另建立一个class：Eesay,代码如下
public class Eesay {
private String title;
private String author;
private String content;
public Eesay(String title, String author, String content) {
this.title = title;
this.author = author;
this.content = content;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
}//将操作权交还给主线程
Eesay e=new Eesay(title,author,content);
Message message=handler.obtainMessage();
message.obj=e;
//调用此方法则会触发主线程中handler对象下覆盖的HandlerMessage方法
handler.sendMessage(message);
使用Handler
private Handler handler=new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
Eesay e= (Eesay) msg.obj;
nameView.setText(e.getTitle());
authorView.setText(e.getAuthor());
contentView.setText(e.getContent());
}
};