由于我遇到了同样的问题,我尝试了一个更通用的解决方案[1],ContainerResponseFilter
它会在请求中存在标头时触发,Range
并且可以与任何媒体类型、实体和资源方法无缝协作。
这是ContainerResponseFilter
将使用封装输出流的方法RangedOutputStream
(见下文):
public class RangeResponseFilter implements ContainerResponseFilter {
private static final String RANGE = "Range";
private static final String ACCEPT_RANGES = "Accept-Ranges";
@Override
public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext)
throws IOException {
if (requestContext.getHeaders().containsKey(RANGE)) {
String rangeHeader = requestContext.getHeaderString(RANGE);
String contentType = responseContext.getMediaType().toString();
OutputStream originOutputStream = responseContext.getEntityStream();
RangedOutputStream rangedOutputStream = new RangedOutputStream(originOutputStream, rangeHeader, contentType, responseContext.getHeaders());
responseContext.setStatus(Status.PARTIAL_CONTENT.getStatusCode());
responseContext.getHeaders().putSingle(ACCEPT_RANGES, rangedOutputStream.getAcceptRanges());
responseContext.setEntityStream(rangedOutputStream);
}
}
}
这是RangedOutputStream
:
public class RangedOutputStream extends OutputStream {
public class Range extends OutputStream {
private ByteArrayOutputStream outputStream;
private Integer from;
private Integer to;
public Range(Integer from, Integer to) {
this.outputStream = new ByteArrayOutputStream();
this.from = from;
this.to = to;
}
public boolean contains(Integer i) {
if (this.to == null) {
return (this.from <= i);
}
return (this.from <= i && i <= this.to);
}
public byte[] getBytes() {
return this.outputStream.toByteArray();
}
public Integer getFrom() {
return this.from;
}
public Integer getTo(Integer ifNull) {
return this.to == null ? ifNull : this.to;
}
@Override
public void write(int b) throws IOException {
this.outputStream.write(b);
}
}
private final static char[] MULTIPART_CHARS = "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
.toCharArray();
private static final String BOUNDARY_LINE_FORMAT = "--%s";
private static final String CONTENT_TYPE_LINE_FORMAT = "Content-Type: %s";
private static final String CONTENT_RANGE_FORMAT = "%s %d-%d/%d";
private static final String CONTENT_RANGE_LINE_FORMAT = "Content-Range: " + CONTENT_RANGE_FORMAT;
private static final String EMPTY_LINE = "\r\n";
private OutputStream outputStream;
private String boundary;
private String accept;
private String contentType;
private boolean multipart;
private boolean flushed = false;
private int pos = 0;
List<Range> ranges;
MultivaluedMap<String, Object> headers;
public RangedOutputStream(OutputStream outputStream, String ranges, String contentType, MultivaluedMap<String, Object> headers) {
this.outputStream = outputStream;
this.ranges = new ArrayList<>();
String[] acceptRanges = ranges.split("=");
this.accept = acceptRanges[0];
for (String range : acceptRanges[1].split(",")) {
String[] bounds = range.split("-");
this.ranges.add(new Range(Integer.valueOf(bounds[0]), bounds.length == 2 ? Integer.valueOf(bounds[1]) : null ));
}
this.headers = headers;
this.contentType = contentType;
this.multipart = this.ranges.size() > 1;
this.boundary = this.generateBoundary();
}
private String generateBoundary() {
StringBuilder buffer = new StringBuilder();
Random rand = new Random();
int count = rand.nextInt(11) + 30;
for (int i = 0; i < count; i++) {
buffer.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]);
}
return buffer.toString();
}
public boolean isMultipart() {
return this.multipart;
}
public String getBoundary() {
return this.boundary;
}
public String getAcceptRanges() {
return this.accept;
}
public String getContentRange(int index) {
Range range = this.ranges.get(index);
return String.format(CONTENT_RANGE_LINE_FORMAT, this.accept, range.getFrom(), range.getTo(this.pos), this.pos);
}
@Override
public void write(int b) throws IOException {
for (Range range : this.ranges) {
if (range.contains(this.pos)) {
range.write(b);
}
}
this.pos++;
}
@Override
public void flush() throws IOException {
if (this.flushed) {
return;
}
if (this.multipart) {
this.headers.putSingle(HttpHeaders.CONTENT_TYPE, String.format("multipart/byteranges; boundary=%s", this.boundary));
for (Range range : this.ranges) {
this.outputStream.write(String.format(BOUNDARY_LINE_FORMAT + EMPTY_LINE, this.boundary).getBytes());
this.outputStream.write(String.format(CONTENT_TYPE_LINE_FORMAT + EMPTY_LINE, this.contentType).getBytes());
this.outputStream.write(
String.format(CONTENT_RANGE_LINE_FORMAT + EMPTY_LINE, this.accept, range.getFrom(), range.getTo(this.pos), this.pos)
.getBytes());
this.outputStream.write(EMPTY_LINE.getBytes());
this.outputStream.write(range.getBytes());
this.outputStream.write(EMPTY_LINE.getBytes());
}
this.outputStream.write(String.format(BOUNDARY_LINE_FORMAT, this.boundary + "--").getBytes());
} else {
Range range = this.ranges.get(0);
this.headers.putSingle("Content-Range", String.format(CONTENT_RANGE_FORMAT, this.accept, range.getFrom(), range.getTo(this.pos), this.pos));
this.outputStream.write(range.getBytes());
}
this.flushed = true;
}
}
[1] https://github.com/heruan/jersey-range-filter