Android读取服务器图片流的两种方法

参考地址：

android 服务器获取图片路径,Android读取服务器图片的三种方法_猪猪堂客的博客-CSDN博客

 Android HttpRequest_AaronZhao的博客-CSDN博客

 Android get获取InputStream后转换不成bitmap，或者转换为bitmap不显示_android inputstream转bitmap_罴之力量的博客-CSDN博客

package com.pic.utils;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.BufferedHttpEntity;
import org.apache.http.impl.client.DefaultHttpClient;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * 通过输出流的方式获取服务器中图片
 * 说明：如果服务器中的图片在浏览器中直接打开出现下载时，在Android中
 *  则不能通过WebView查看，需要通过图片地址获取到图片的流并转成bitmap才可以查看；
 *  以下两种方法是通过HttpURLConnection或HttpClient的形式来获取输出流，通过测试
 *  HttpURLConnection不能正确获取到图片并会报405（猜测和后端配置有关）；
 *  HttpClient通过GET请求则可以获取到图片内容，如果图片地址需要Cookies才可以
 *  查看，则需要加请求头
 */
public class PICUtils {
    //1.使用HttpURLConnection获取服务器图片流
    public String getPIC(String fileName){
        try {
            // 根据地址创建URL对象
            URL url = new URL(MyUrl.url +fileName);
            // 根据URL对象打开链接
            HttpURLConnection urlConnection = (HttpURLConnection) url
                    .openConnection();
            // 设置请求的方式
            urlConnection.setRequestMethod("GET");
            // 设置请求的超时时间
            urlConnection.setReadTimeout(1000*30);
            urlConnection.setConnectTimeout(1000*30);
            // 传递的数据
            String data = "";
            urlConnection.setRequestProperty("Cookie","");
            // 设置请求的头
            urlConnection.setRequestProperty("Connection", "keep-alive");
            // 设置请求的头
            urlConnection.setRequestProperty("Content-Type",
                    "application/json");
            // 设置请求的头
            urlConnection.setRequestProperty("Content-Length",
                    String.valueOf(data.getBytes().length));
            // 设置请求的头
            urlConnection.setRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 6.3; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0");
            urlConnection.setDoOutput(true); // 发送POST请求必须设置允许输出
            urlConnection.setDoInput(true); // 发送POST请求必须设置允许输入
            //setDoInput的默认值就是true
            //获取输出流
            OutputStream os = urlConnection.getOutputStream();
            os.write(data.getBytes());
            os.flush();
            if (urlConnection.getResponseCode() == 200) {
                // 获取响应的输入流对象
                InputStream is = urlConnection.getInputStream();
                //1.获取Bitmap
                //(1)
                // Bitmap bitmap = BitmapFactory.decodeStream(is);
                //(2)如果上边不能正确获取到bitmap则使用以下方法
                // byte[] bytes = readStream(is);
                //Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

                //2.创建字节输出流对象
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                // 定义读取的长度
                int len = 0;
                // 定义缓冲区
                byte buffer[] = new byte[1024];
                // 按照缓冲区的大小，循环读取
                while ((len = is.read(buffer)) != -1) {
                    // 根据读取的长度写入到os对象中
                    baos.write(buffer, 0, len);
                }
                // 释放资源
                is.close();
                baos.close();
                // 返回字符串
                String result = new String(baos.toByteArray());
                System.out.println("getPIC1:::"+result);
                return result;
            } else {
                System.out.println("getPIC1:::"+urlConnection.getResponseCode());
            }
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("getPIC1:::"+e.fillInStackTrace());
        }
        return null;
    }
    //2.使用HttpClient获取服务器图片流
    public String getPIC2(String fileName){
        try {
            //生成一个请求对象
            HttpGet httpGet = new HttpGet(MyUrl.url +fileName);
            //请求头
            httpGet.addHeader("Cookie","自己的Cookie");
            //生成一个Http客户端对象
            HttpClient httpClient = new DefaultHttpClient();
            //httpResponse就是代表响应对象
            HttpResponse httpResponse=httpClient.execute(httpGet);
            int i = httpResponse.getStatusLine().getStatusCode();
            if (i==200){
                //httpEntity包含的就是返回的消息内容
                HttpEntity httpEntity = httpResponse.getEntity();
                //1.获取响应数据String
//                InputStream inputStream =httpEntity.getContent();
//                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
//                StringBuilder result=new StringBuilder("");
//                String line = "";
//                while((line=reader.readLine())!=null){
//                    result.append(line);
//                }
//                inputStream.close();
//                System.out.println("getPIC2:::"+result.toString());
//                return result.toString();
                //2.获取Bitmap
                BufferedHttpEntity bufferedHttpEntity = new BufferedHttpEntity(httpEntity);
                InputStream is = bufferedHttpEntity.getContent();
                byte[] bytes = readStream(is);
                Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
                return "";
            }else{
                System.out.println("getPIC2:::"+i);
            }
        } catch (Exception e) {
            System.out.println("getPIC2:::"+e.fillInStackTrace());
        }
        return null;
    }
    //输入流转bitmap
    public static byte[] readStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream  outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, len);
        }
        byte[] bytes = outStream.toByteArray();
        outStream.close();
        inStream.close();
        return bytes;
    }
}