android获取网络输出字符串流的三种方式

• HttpURLCnnection获取网络流
• AsyncHttpClient获取网络流
• okhttp获取网络流（推荐使用，效率更高）

方法一：HttpURLCnnection

• 工具类：HttpUtils

public class HttpUtils {

    public HttpUtils() {
        // TODO Auto-generated constructor stub
    }

    public static String getJsonContent(String url_path) {
        try {
            URL url = new URL(url_path);
            HttpURLConnection connection = (HttpURLConnection) url
                    .openConnection();
            connection.setConnectTimeout(3000);
            connection.setRequestMethod("GET");
            connection.setDoInput(true);
            int code = connection.getResponseCode();
            if (code == 200) {
                return changeInputStream(connection.getInputStream());
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
        return "";
    }

    private static String changeInputStream(InputStream inputStream) {
        // TODO Auto-generated method stub
        String jsonString = "";
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        int len = 0;
        byte[] data = new byte[1024];
        try {
            while ((len = inputStream.read(data)) != -1) {
                outputStream.write(data, 0, len);
            }
            jsonString = new String(outputStream.toByteArray());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return jsonString;
    }
}

• 然后，在线程里调用该类

  Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                
                String path = "http://10.08.4.48:8080/TomcatResourse/test.json";
                String jsonString = HttpUtils.getJsonContent(path2);//从网络获取数据
                Log.i("测试",  jsonString);
                jsonTojava(jsonString);//传入json格式字符串，执行解析步骤

            }
        });
        thread.start();
    }

 方法二、asynchttpClient

• compile 'com.loopj.android:android-async-http:1.4.9'

•  

  AsyncHttpClient

AsyncHttpClient client=new AsyncHttpClient();
        client.get(path, new AsyncHttpResponseHandler() {
            @Override
            public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {

                ByteArrayInputStream bais=new ByteArrayInputStream(responseBody);
                String JSON=changeInputStream(bais);//调用changeInputStream 转换为String

            }//OK

            @Override
            public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
                Toast.makeText(mContext, "网络数据获取失败",
                        Toast.LENGTH_SHORT).show();

            }
        });
    }*/

•  调用changeInputStream()，格式化为String

private static String changeInputStream(InputStream inputStream) {
        // TODO Auto-generated method stub
        String jsonString = "";
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        int len = 0;
        byte[] data = new byte[1024];
        try {
            while ((len = inputStream.read(data)) != -1) {
                outputStream.write(data, 0, len);
            }
            jsonString = new String(outputStream.toByteArray());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return jsonString;
    }*/

方法三、okhttp

compile 'com.squareup.okhttp3:okhttp:3.4.1'

 封装工具类：AsynHttp.java

import android.os.Handler;
import android.os.Message;
import android.util.Log;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

/**
 * Created by Duan on 2018/12/31.
 */

class AsynHttp {
    OkHttpClient mOkHttpClient;
    /**
     * Ansy
     * @param Url 访问链接
     * @param ansyCallback 回调接口
     */
    public void getAsynHttp(final String Url,final AnsyCallback ansyCallback){
        final Handler handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                ansyCallback.AnsyLoader((T)msg.obj,Url);
            }
        };
        mOkHttpClient = new OkHttpClient();
        Request.Builder requestBuilder = new Request.Builder().url(Url);
        requestBuilder.method("GET",null);
        Request request = requestBuilder.build();
        Call mcall = mOkHttpClient.newCall(request);
        mcall.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
            }
            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (null != response.cacheResponse()) {
                    String str = response.cacheResponse().toString();
                    Message message = handler.obtainMessage(0,str);
                    handler.sendMessage(message);
                    Log.i("wangshu", "cache---" + str);
                } else {
                    String d = response.body().string();
                    String str = response.networkResponse().toString();
                    Message message = handler.obtainMessage(0,d);
                    handler.sendMessage(message);
                    Log.i("wangshu", "network---" + str);
                }
            }
        });
    }
    //接口
    public interface AnsyCallback {
        public void AnsyLoader(T loder, String Url);
    }

}

调用：

   AsynHttp asynHttp = new AsynHttp<>();
        asynHttp.getAsynHttp("http://47.106.168.173:8080/TestJson/goods.json", new AsynHttp.AnsyCallback() {
            @Override
            public void AnsyLoader(String loder, String Url) {
                //此处UI线程
//在此处更新UI  loder:网络输出字符串流
                //TextView textView = (TextView)findViewById(R.id.abc);
               // textView.setText(loder);
            }
        });