javax.ws.rs.core.EntityTag#valueOf()源码实例Demo

private ResponseBuilder evaluateIfMatch(EntityTag eTag, Date date) {
    List<String> ifMatch = headers.getRequestHeader(HttpHeaders.IF_MATCH);

    if (ifMatch == null || ifMatch.isEmpty()) {
        return date == null ? null : evaluateIfNotModifiedSince(date);
    }

    try {
        for (String value : ifMatch) {
            if ("*".equals(value)) {
                return null;
            }
            EntityTag requestTag = EntityTag.valueOf(value);
            // must be a strong comparison
            if (!requestTag.isWeak() && !eTag.isWeak() && requestTag.equals(eTag)) {
                return null;
            }
        }
    } catch (IllegalArgumentException ex) {
        // ignore
    }
    return Response.status(Response.Status.PRECONDITION_FAILED).tag(eTag);
}
 

/**
 * Comparison for If-None-Match header and ETag.
 *
 * @param etag
 *         the ETag
 * @return ResponseBuilder with status 412 (precondition failed) if If-None-Match header is MATCH to ETag and HTTP method is not GET or
 * HEAD. If method is GET or HEAD and If-None-Match is MATCH to ETag then ResponseBuilder with status 304 (not modified) will be
 * returned.
 */
private ResponseBuilder evaluateIfNoneMatch(EntityTag etag) {
    String ifNoneMatch = getRequestHeaders().getFirst(IF_NONE_MATCH);

    if (Strings.isNullOrEmpty(ifNoneMatch)) {
        return null;
    }

    EntityTag otherEtag = EntityTag.valueOf(ifNoneMatch);
    String httpMethod = getMethod();
    if (httpMethod.equals(GET) || httpMethod.equals(HEAD)) {
        if (eTagsWeakEqual(etag, otherEtag)) {
            return Response.notModified(etag);
        }
    } else {
        if (eTagsStrongEqual(etag, otherEtag)) {
            return Response.status(PRECONDITION_FAILED);
        }
    }
    return null;
}
 

private ResponseBuilder evaluateIfNonMatch(EntityTag eTag, Date lastModified) {
    List<String> ifNonMatch = headers.getRequestHeader(HttpHeaders.IF_NONE_MATCH);

    if (ifNonMatch == null || ifNonMatch.isEmpty()) {
        return lastModified == null ? null : evaluateIfModifiedSince(lastModified);
    }

    String method = getMethod();
    boolean getOrHead = HttpMethod.GET.equals(method) || HttpMethod.HEAD.equals(method);
    try {
        for (String value : ifNonMatch) {
            boolean result = "*".equals(value);
            if (!result) {
                EntityTag requestTag = EntityTag.valueOf(value);
                result = getOrHead ? requestTag.equals(eTag)
                    : !requestTag.isWeak() && !eTag.isWeak() && requestTag.equals(eTag);
            }
            if (result) {
                Response.Status status = getOrHead ? Response.Status.NOT_MODIFIED
                    : Response.Status.PRECONDITION_FAILED;
                return Response.status(status).tag(eTag);
            }
        }
    } catch (IllegalArgumentException ex) {
        // ignore
    }
    return null;
}
 

@Test
public void testFromString() {
    EntityTag tag = EntityTag.valueOf("\"\"");
    assertFalse(tag.isWeak() && "".equals(tag.getValue()));
    tag = EntityTag.valueOf("W/");
    assertTrue(tag.isWeak() && "".equals(tag.getValue()));
    tag = EntityTag.valueOf("W/\"12345\"");
    assertTrue(tag.isWeak() && "12345".equals(tag.getValue()));
    tag = EntityTag.valueOf("\"12345\"");
    assertFalse(tag.isWeak() && "12345".equals(tag.getValue()));
}
 

@Override
public EntityTag getEntityTag() {
    Object value = getMetadata().getFirst(ETAG);
    if (value == null) {
        return null;
    }
    if (value instanceof EntityTag) {
        return (EntityTag)value;
    }
    return EntityTag.valueOf(value instanceof String ? (String)value : getHeaderAsString(value));
}
 

/**
 * Comparison for If-Match header and ETag.
 *
 * @param etag
 *         the ETag
 * @return ResponseBuilder with status 412 (precondition failed) if If-Match header does NOT MATCH to ETag or null otherwise
 */
private ResponseBuilder evaluateIfMatch(EntityTag etag) {
    String ifMatch = getRequestHeaders().getFirst(IF_MATCH);

    if (isNullOrEmpty(ifMatch)) {
        return null;
    }

    EntityTag otherEtag = EntityTag.valueOf(ifMatch);

    if (eTagsStrongEqual(etag, otherEtag)) {
        return null;
    }
    return Response.status(PRECONDITION_FAILED);
}
 

public EntityTag getEntityTag() {
    Object header = metadata.getFirst(HttpHeaders.ETAG);
    return header == null || header instanceof EntityTag ? (EntityTag)header
        : EntityTag.valueOf(header.toString());
}
 

@Test(expected = IllegalArgumentException.class)
public void testNullValue() throws Exception {
    EntityTag.valueOf(null);
}