[移动开发]Android studio中HttpClient学习笔记

Get获取数据步骤

1.创造HttpClient对象
2.创造HttpGet请求对象(访问的服务器地址)
3.执行请求，服务器响应结果放在请求对象中
4.根据状态码判断请求结果，200表示正常
5.取出返回对象的entity里的数据

例子：获取网易新闻字符串代码

链接如图: link.

1. 新建一个类HttpclientClass

public class HttpclientClass {
    public static String getDataString(String urlPath){
        String datastring ="";
        //1.创造HttpClient对象
        HttpClient httpClient = new DefaultHttpClient();
        //2.创造HttpGet请求对象(访问的服务器地址)
        HttpGet httpGet = new HttpGet(urlPath);
        //3.执行请求，服务器响应结果放在请求对象中
        try {
            HttpResponse response = httpClient.execute(httpGet);
            //4.根据状态码判断请求结果，200表示正常
            if(response.getStatusLine().getStatusCode()==200){
                //5.取出entity里的数据
                HttpEntity entity = response.getEntity();
                String result = EntityUtils.toString(entity,"utf-8");
                datastring=result;
                Log.i("LXH", "result: "+result );
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return datastring;
    }
}

当出现Cannot resolve symbol ‘HttpClient’时，在build.gradle(Module:app)的android{}里添加：useLibrary ‘org.apache.http.legacy’，进行Sync重新build一下即可。

2. Activity中代码

public class Main3Activity extends AppCompatActivity {
    TextView tvHttpClient;
    Handler handler;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main3);
        tvHttpClient=findViewById(R.id.tvHttpClient);
        handler = new Handler(){
            @Override
            public void handleMessage(@NonNull Message msg) {
                super.handleMessage(msg);
                //处理消息
                if(msg.what==1){
                    String response=(String)msg.obj;
                    tvHttpClient.setText(response);
                }
            }
        };
        new Thread(){
            @Override
            public void run() {
                super.run();
                String netdata="";
                netdata=HttpclientClass.getDataString("http://c.m.163.com/nc/article/headline/T1348647853363/0-40.html");
                Log.i("LXH","access"+netdata);
                Message msg =Message.obtain();
                msg.what=1;
                msg.obj=netdata;
                handler.sendMessage(msg);
            }
        }.start();
    }
}

3. xml文件代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
        <TextView
            android:id="@+id/tvHttpClient"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="" />
    </ScrollView>
</LinearLayout>

4. 在清单中添加网络权限

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

5. 运行结果如图
   

扩展

将得到的字符串解析