Asynctask异步处理类的使用

主类

package com.example.day08_asynctask;

import java.util.concurrent.ExecutionException;

import android.os.Bundle;
import android.R.integer;
import android.app.Activity;
import android.view.Menu;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends Activity {
TextView tv;
TextView tv2;
ProgressBar pb;
String key = "3ac9f31ff66b9746539472887b3799c3";
// 通过get请求时的接口地址
String get_path = "http://web.juhe.cn:8080/constellation/getAll?consName=狮子座&type=today&key="
+ key;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.textView1);
tv2 = (TextView) findViewById(R.id.textView2);
pb = (ProgressBar) findViewById(R.id.progressBar1);
// 主页提供控件，和联网地址
System.out.println("new 出对象");
MyAsynctask myAsynctask = new MyAsynctask(tv, pb);
System.out.println("执行extcte方法");
// 执行完，这里先得到执行的结果，类中在得到
myAsynctask.execute(get_path);
try {
String string = myAsynctask.get();
System.out.println("主线程得到线程结束的数据：" + string);
tv2.setText("主线程的设置" + string);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}

}

线程类

package com.example.day08_asynctask;

import java.io.BufferedReader;
import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import android.os.AsyncTask;
import android.os.SystemClock;
import android.widget.ProgressBar;
import android.widget.TextView;
// 三个参数，1.线程执行前传入的数据类型 params 2.线程中更新的数据类型 3.线程执行后的结果类型
public class MyAsynctask extends AsyncTask<String, Integer, String> {

TextView tv;
ProgressBar pb;
String path = "";
private BufferedReader br;
private StringBuffer sb;
private String str;

public MyAsynctask(TextView tv, ProgressBar pb) {
super();
this.tv = tv;
this.pb = pb;
}

// 开启后台线程
@Override
protected String doInBackground(String... params) {
System.out.println("正式开启线程,得到传来的数据" + params[0]);
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(params[0]);
try {
HttpResponse httpResponse = httpClient.execute(httpGet);
if (httpResponse.getStatusLine().getStatusCode() == 200) {
HttpEntity entity = httpResponse.getEntity();
str = EntityUtils.toString(entity);
for (Integer i = 0; i < 100; i++) {
SystemClock.sleep(200);
publishProgress(i);
}
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return str;
}

// 开始后台线程前执行
@Override
protected void onPreExecute() {

System.out.println("准备开启线程");
super.onPreExecute();
}

@Override
protected void onPostExecute(String result) {
System.out.println("子类线程得到结果数据：" + result);
tv.setText("任务类设置的信息" + str);
super.onPostExecute(result);
}

@Override
protected void onProgressUpdate(Integer... values) {
System.out.println("线程执行中得到传来的数据" + values[0]);
tv.setText(values[0] + "%");
super.onProgressUpdate(values);
}

}