Java 将图像从服务器下载到android并在imageview中显示
我有一个服务器(我使用GlassFish)。我能够通过http将Json或XML等发送到我的android设备。我看到了一个从android设备上传图片到服务器的例子。它将我拾取的图像转换为字节,转换为字符串并返回到我的服务器。所以我可以把它放在我的电脑(服务器)上。 现在我只想要相反的结果:从我的PC上获取一张图片,并使用URL将图像(此处的位图)获取到imageview。但在调试过程中,bmp似乎为“null”。谷歌说这是因为我的图像不是有效的位图(所以我的服务器编码可能有问题?)。 我需要对该代码进行哪些更改才能使其正常工作 服务器代码:Java 将图像从服务器下载到android并在imageview中显示,java,android,Java,Android,我有一个服务器(我使用GlassFish)。我能够通过http将Json或XML等发送到我的android设备。我看到了一个从android设备上传图片到服务器的例子。它将我拾取的图像转换为字节,转换为字符串并返回到我的服务器。所以我可以把它放在我的电脑(服务器)上。 现在我只想要相反的结果:从我的PC上获取一张图片,并使用URL将图像(此处的位图)获取到imageview。但在调试过程中,bmp似乎为“null”。谷歌说这是因为我的图像不是有效的位图(所以我的服务器编码可能有问题?)。 我需要
public class getImage{
String imageDataString = null;
@GET
@Path("imageid/{id}")
public String findImageById(@PathParam("id") Integer id) {
//todo: schrijf een query voor het juiste pad te krijgen!
System.out.println("in findImageById");
File file = new File("C:\\Users\\vulst\\Desktop\\MatchIDImages\\Results\\R\\Tensile_Hole_2177N.tif_r.bmp");
try{
// Reading a Image file from file system
FileInputStream imageInFile = new FileInputStream(file);
byte imageData[] = new byte[(int) file.length()];
imageInFile.read(imageData);
// Converting Image byte array into Base64 String
imageDataString = Base64.encodeBase64URLSafeString(imageData);
imageInFile.close();
System.out.println("Image Successfully Manipulated!");
} catch (FileNotFoundException e) {
System.out.println("Image not found" + e);
} catch (IOException ioe) {
System.out.println("Exception while reading the Image " + ioe);
}
return imageDataString;
}
}
这是android端(android studio):
公共类XMLTask扩展了AsyncTask{
@凌驾
受保护的字符串doInBackground(字符串…URL){
HttpURLConnection=null;
BufferedReader reader=null;
试一试{
java.net.URL URL=新URL(URL[0]);
connection=(HttpURLConnection)url.openConnection();
connection.connect();
InputStream=connection.getInputStream();
reader=新的BufferedReader(新的InputStreamReader(流));
StringBuffer=新的StringBuffer();
字符串行=”;
而((line=reader.readLine())!=null){
buffer.append(行);
}
返回buffer.toString();
}捕获(格式错误){
e、 printStackTrace();
}捕获(IOE异常){
e、 printStackTrace();
}最后{
if(连接!=null){
连接断开();
}
试一试{
if(读卡器!=null){
reader.close();
}
}捕获(IOE异常){
e、 printStackTrace();
}
}
返回null;
}
@凌驾
受保护的void onPostExecute(字符串行){
super.onPostExecute(行);
字节[]imageByteArray=Base64.decode(第行,Base64.DEFAULT);
试一试{
位图bmp=BitmapFactory.decodeByteArray(imageByteArray,0,imageByteArray.length);
设置图像位图(bmp);
}捕获(例外e){
Log.d(“tag”,例如toString());
}
}
}
为什么不使用
对于应用程序模块中的build.gradle
:
dependencies {
compile 'com.github.bumptech.glide:glide:3.7.0'
...
}
然后:
你为什么不使用
对于应用程序模块中的build.gradle
:
dependencies {
compile 'com.github.bumptech.glide:glide:3.7.0'
...
}
然后:
尝试使用
Base64.encodeBase64String(imageData)
不使用urlsafetstring
尝试使用Base64.encodeBase64String(imageData)
不使用urlsafetstring您可以使用Glide这是加载图像的最简单方法
这就是保存图像的方法
Glide.with(context)
.load(image)
.asBitmap()
.into(new SimpleTarget<Bitmap>() {
@Override
public void onResourceReady(Bitmap resource, GlideAnimation<? super Bitmap> glideAnimation) {
String name = new Date().toString() + ".jpg";
imageName = imageName + name.replaceAll("\\s+", "");
Log.d(TAG, "onResourceReady: imageName = " + imageName);
ContextWrapper contextWrapper = new ContextWrapper(mContext);
File directory = contextWrapper.getDir("imageDir", Context.MODE_PRIVATE);
File myPath = new File(directory, imageName);
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(myPath);
resource.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
您可以使用Glide,这是加载图像的最简单方法
这就是保存图像的方法
Glide.with(context)
.load(image)
.asBitmap()
.into(new SimpleTarget<Bitmap>() {
@Override
public void onResourceReady(Bitmap resource, GlideAnimation<? super Bitmap> glideAnimation) {
String name = new Date().toString() + ".jpg";
imageName = imageName + name.replaceAll("\\s+", "");
Log.d(TAG, "onResourceReady: imageName = " + imageName);
ContextWrapper contextWrapper = new ContextWrapper(mContext);
File directory = contextWrapper.getDir("imageDir", Context.MODE_PRIVATE);
File myPath = new File(directory, imageName);
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(myPath);
resource.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
您是否尝试过HttpURlConnection
下面是一个示例代码:
private class SendHttpRequestTask extends AsyncTask<String, Void, Bitmap> {
@Override
protected Bitmap doInBackground(String... params) {
try {
URL url = new URL("http://xxx.xxx.xxx/image.jpg");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
}catch (Exception e){
Log.d(TAG,e.getMessage());
}
return null;
}
@Override
protected void onPostExecute(Bitmap result) {
ImageView imageView = (ImageView) findViewById(ID OF YOUR IMAGE VIEW);
imageView.setImageBitmap(result);
}
}
私有类SendHttpRequestTask扩展了AsyncTask{
@凌驾
受保护位图doInBackground(字符串…参数){
试一试{
URL=新URL(“http://xxx.xxx.xxx/image.jpg");
HttpURLConnection connection=(HttpURLConnection)url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream输入=连接。getInputStream();
位图myBitmap=BitmapFactory.decodeStream(输入);
返回我的位图;
}捕获(例外e){
Log.d(标记,例如getMessage());
}
返回null;
}
@凌驾
受保护的void onPostExecute(位图结果){
ImageView ImageView=(ImageView)findViewById(图像视图的ID);
设置图像位图(结果);
}
}
我希望我能帮你你试过HttpURlConnection
吗
下面是一个示例代码:
private class SendHttpRequestTask extends AsyncTask<String, Void, Bitmap> {
@Override
protected Bitmap doInBackground(String... params) {
try {
URL url = new URL("http://xxx.xxx.xxx/image.jpg");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
}catch (Exception e){
Log.d(TAG,e.getMessage());
}
return null;
}
@Override
protected void onPostExecute(Bitmap result) {
ImageView imageView = (ImageView) findViewById(ID OF YOUR IMAGE VIEW);
imageView.setImageBitmap(result);
}
}
私有类SendHttpRequestTask扩展了AsyncTask{
@凌驾
受保护位图doInBackground(字符串…参数){
试一试{
URL=新URL(“http://xxx.xxx.xxx/image.jpg");
HttpURLConnection connection=(HttpURLConnection)url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream输入=连接。getInputStream();
位图myBitmap=BitmapFactory.decodeStream(输入);
返回我的位图;
}捕获(例外e){
Log.d(标记,例如getMessage());
}
返回null;
}
@凌驾
受保护的void onPostExecute(位图结果){
ImageView ImageView=(ImageView)findViewById(图像视图的ID);
设置图像位图(结果);
}
}
我希望我能帮上忙如果有人也试图用我的方式做这件事,这很有效:
public class XMLTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... urls) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
java.net.URL url = new URL(urls[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPostExecute(String line) {
super.onPostExecute(line);
byte[] imageByteArray = Base64.decode(line , Base64.DEFAULT);
try {
Bitmap bmp = BitmapFactory.decodeByteArray(imageByteArray, 0, imageByteArray.length);
ivFoto.setImageBitmap(bmp);
}catch (Exception e){
Log.d("tag" , e.toString());
}
}
}
如果有人也试图用我的方式来做,这是有效的:
public class XMLTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... urls) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
java.net.URL url = new URL(urls[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPostExecute(String line) {
super.onPostExecute(line);
byte[] imageByteArray = Base64.decode(line , Base64.DEFAULT);
try {
Bitmap bmp = BitmapFactory.decodeByteArray(imageByteArray, 0, imageByteArray.length);
ivFoto.setImageBitmap(bmp);
}catch (Exception e){
Log.d("tag" , e.toString());
}
}
}
我希望这段代码是有用的
转到MainActivity.java并尝试以下代码:
public class MainActivity extends AppCompatActivity {
ImageView imageView;
public void downloadImage(View view)
{
Log.i("Button","Tapped");
DownloadImage task = new DownloadImage();
Bitmap result = null;
try {
result = task.execute("https://vignette.wikia.nocookie.net/disney/images/0/0a/ElsaPose.png/revision/latest?cb=20170221004839").get();
}
catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
imageView.setImageBitmap(result);
}
public class DownloadImage extends AsyncTask<String, Void, Bitmap>
{
@Override
protected Bitmap doInBackground(String... imageurls) {
URL url;
HttpURLConnection httpURLConnection;
try {
url = new URL(imageurls[0]);
httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.connect();
InputStream in =httpURLConnection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(in);
return myBitmap;
}
catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = (ImageView)findViewById(R.id.imageView);
}
public类MainActivity扩展了AppCompatActivity{
图像视图图像视图;
公共void下载图像(视图)
{
Log.i(“按钮”、“点击”);
DownloadImage任务=新建DownloadImage();
位图结果=空;
试一试{
结果=任务。执行(“https://vignette.wikia.nocookie.net/disney/images/0/0a/ElsaPose.png/revision/latest?cb=20170221004839).get();
}
捕获(中断异常|执行异常e){
e、 printStackTrace();
}
设置图像位图(结果);
}
公共课做什么
<uses-permission android:name="android.permission.INTERNET"/>