CODEWITHSUNDEEP
resthttp-headersjax-rsresteasy
Dilini Rajapaksha
Dilini Rajapaksha

Reputation: 2718

Jax-rs http header range

I want to use the http header 'Range' in a Jax-rs application, can I define a unit for this? for example, number of records.

What I want to implement is to limit the number of records returned in the response to the maximum value of the 'Range'

Upvotes: 2

Views: 983

Answers (1)

lefloh
lefloh

Reputation: 10961

For parsing more complex Parameters you can implement a ParamConverter:

@Provider
public class RangeHeaderConverter implements ParamConverter<RangeHeader> {

    @Override
    public RangeHeader fromString(String value) {
        return RangeHeader.fromValue(value);
    }

    @Override
    public String toString(RangeHeader value) {
        return value.toString();
    }

}

The implementation of your RangeHeader might look like this:

public class RangeHeader {

    public static enum Unit {
        BYTES;
    }

    private Unit unit;

    private long from;

    private long to;

    public RangeHeader(Unit unit, long from, long to) {
        this.unit = unit;
        this.from = from;
        this.to = to;
    }

    public Unit getUnit() {
        return unit;
    }

    public long getFrom() {
        return from;
    }

    public long getTo() {
        return to;
    }

    public static RangeHeader fromValue(String range) {
        if (range == null) {
            return null;
        }
        String[] tokens = range.replace("Range: ", "").split("=");
        Unit unit = Unit.valueOf(tokens[0].toUpperCase());
        String[] fromTo = tokens[1].split("-");
        long from = Long.valueOf(fromTo[0]);
        long to = Long.valueOf(fromTo[1]);
        return new RangeHeader(unit, from, to);
    }

    public String toString() {
        return String.format("Range: %s=%d-%d", unit.name().toLowerCase(), from, to);
    }

}

You can use this class like this:

public Response get(@HeaderParam("Range") RangeHeader range) {
    //
}

Note: This is just a quick+dirty implementation and doesn't handle special values or errors.

Upvotes: 3

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