Why can't I read an image from a byte array?
When I use
Here's my code:
JDK: open jdk 21
ImageIO.read(URL)ImageIO.read(URL), I get the image without any problems, but if I read bytes from the link in my own way, write them to an array and then try to convert them into an image, the ImageIO.read(ByteArrayInputStream)ImageIO.read(ByteArrayInputStream) method returns null.Here's my code:
private URLResponse buildResponse(HttpURLConnection connection) throws IOException {
int responseCode = connection.getResponseCode();
HashMap<String, String> headers = new HashMap<>();
for (Map.Entry<String, java.util.List<String>> headerEntry : connection.getHeaderFields().entrySet()) {
headers.put(headerEntry.getKey(), String.join(",", headerEntry.getValue()));
}
ByteArrayOutputStream baos;
if("45".contains(String.valueOf(responseCode).substring(0, 1))) {
baos = readStream(connection.getErrorStream());
}else{
baos = readStream(connection.getInputStream());
}
return new URLResponse(responseCode, baos.toByteArray(), headers);
}
private ByteArrayOutputStream readStream(InputStream inputStream) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buff = new byte[4096];
int len;
while ((len = (byte) inputStream.read(buff)) > 0) {
baos.write(buff, 0, len);
}
return baos;
}
public record URLResponse(int code, byte[] bytes, HashMap<String, String> headers) implements Serializable{
@Serial
private static final long serialVersionUID = 1L;
public String response(){
return new String(bytes);
}
public <T> T json(Class<T> clazz) {
return Launch.gson.fromJson(response(), clazz);
}
public BufferedImage image() throws IOException {
BufferedImage bi = ImageIO.read(new ByteArrayInputStream(bytes));
if(bi == null){
throw new NullPointerException("Image is null");
}
return bi;
}
}private URLResponse buildResponse(HttpURLConnection connection) throws IOException {
int responseCode = connection.getResponseCode();
HashMap<String, String> headers = new HashMap<>();
for (Map.Entry<String, java.util.List<String>> headerEntry : connection.getHeaderFields().entrySet()) {
headers.put(headerEntry.getKey(), String.join(",", headerEntry.getValue()));
}
ByteArrayOutputStream baos;
if("45".contains(String.valueOf(responseCode).substring(0, 1))) {
baos = readStream(connection.getErrorStream());
}else{
baos = readStream(connection.getInputStream());
}
return new URLResponse(responseCode, baos.toByteArray(), headers);
}
private ByteArrayOutputStream readStream(InputStream inputStream) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buff = new byte[4096];
int len;
while ((len = (byte) inputStream.read(buff)) > 0) {
baos.write(buff, 0, len);
}
return baos;
}
public record URLResponse(int code, byte[] bytes, HashMap<String, String> headers) implements Serializable{
@Serial
private static final long serialVersionUID = 1L;
public String response(){
return new String(bytes);
}
public <T> T json(Class<T> clazz) {
return Launch.gson.fromJson(response(), clazz);
}
public BufferedImage image() throws IOException {
BufferedImage bi = ImageIO.read(new ByteArrayInputStream(bytes));
if(bi == null){
throw new NullPointerException("Image is null");
}
return bi;
}
}JDK: open jdk 21
