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This commit is contained in:
Juergen Hoeller
2015-07-21 20:33:13 +02:00
parent 7c22d60fd8
commit 1a636b1023
8 changed files with 92 additions and 136 deletions
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157
spring-web/src/main/java/org/springframework/http/CacheControl.java
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@@ -13,6 +13,7 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.http;
import java.util.concurrent.TimeUnit;
@@ -22,79 +23,78 @@ import org.springframework.util.StringUtils;
/**
* A builder for creating "Cache-Control" HTTP response headers.
*
* <p>Adding Cache-Control directives to HTTP responses can significantly improve the client experience when interacting
* with a web application. This builder creates opinionated "Cache-Control" headers with response directives only, with
* several use cases in mind.
* <p>Adding Cache-Control directives to HTTP responses can significantly improve the client
* experience when interacting with a web application. This builder creates opinionated
* "Cache-Control" headers with response directives only, with several use cases in mind.
*
* <ul>
* <li>Caching HTTP responses with {@code CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS)}
* will result in {@code Cache-Control: "max-age=3600"}</li>
* <li>Preventing cache with {@code CacheControl cc = CacheControl.noStore()}
* will result in {@code Cache-Control: "no-store"}</li>
* <li>Advanced cases like {@code CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS).noTransform().cachePublic()}
* will result in {@code Cache-Control: "max-age=3600, no-transform, public"}</li>
* <li>Caching HTTP responses with {@code CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS)}
* will result in {@code Cache-Control: "max-age=3600"}</li>
* <li>Preventing cache with {@code CacheControl cc = CacheControl.noStore()}
* will result in {@code Cache-Control: "no-store"}</li>
* <li>Advanced cases like {@code CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS).noTransform().cachePublic()}
* will result in {@code Cache-Control: "max-age=3600, no-transform, public"}</li>
* </ul>
*
* <p>Note that to be efficient, Cache-Control headers should be written along HTTP validators such as
* "Last-Modifed" or "ETag" headers.
* <p>Note that to be efficient, Cache-Control headers should be written along HTTP validators
* such as "Last-Modified" or "ETag" headers.
*
* @author Brian Clozel
* @author Juergen Hoeller
* @since 4.2
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2">rfc7234 section 5.2.2</a>
* @see <a href="https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching">
* HTTP caching - Google developers reference</a>
* HTTP caching - Google developers reference</a>
* @see <a href="https://www.mnot.net/cache_docs/">Mark Nottingham's cache documentation</a>
* @since 4.2
*/
public class CacheControl {
private boolean mustRevalidate;
private long maxAge = -1;
private boolean noCache;
private boolean noCache = false;
private boolean noStore;
private boolean noStore = false;
private boolean noTransform;
private boolean mustRevalidate = false;
private boolean cachePublic;
private boolean noTransform = false;
private boolean cachePrivate;
private boolean cachePublic = false;
private boolean proxyRevalidate;
private boolean cachePrivate = false;
private long maxAge;
private boolean proxyRevalidate = false;
private long sMaxAge = -1;
private long sMaxAge;
/**
* Create a CacheControl instance with default values,
* i.e. that will produce an empty "Cache-Control" header value.
* Create an empty CacheControl instance.
* @see #empty()
*/
protected CacheControl() {
this.mustRevalidate = false;
this.noCache = false;
this.noStore = false;
this.noTransform = false;
this.cachePublic = false;
this.cachePrivate = false;
this.proxyRevalidate = false;
this.maxAge = -1;
this.sMaxAge = -1;
}
/**
* Return an empty directive.
* <p>This is well suited for using other optional directives without "max-age", "no-cache" or "no-store".
* @return {@code this}, to facilitate method chaining
*/
public static CacheControl empty() {
return new CacheControl();
}
/**
* Add a "max-age=" directive.
*
* <p>This directive is well suited for publicly caching resources, knowing that they won't change within
* the configured amount of time. Additional directives can be also used, in case resources shouldn't be
* cached ({@link #cachePrivate()}) or transformed ({@link #noTransform()}) by shared caches.
*
* <p>In order to prevent caches to reuse the cached response even when it has become stale
* (i.e. the "max-age" delay is passed), the "must-revalidate" directive should be set ({@link #mustRevalidate()}
*
* @param maxAge the maximum time the response should be cached
* @param unit the time unit of the {@code maxAge} argument
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.8">rfc7234 section 5.2.2.8</a>
*/
public static CacheControl maxAge(long maxAge, TimeUnit unit) {
@@ -103,34 +103,15 @@ public class CacheControl {
return cc;
}
/**
* Add a "no-store" directive
*
* <p>This directive is well suited for preventing caches (browsers and proxies) to cache the content of responses.
*
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.3">rfc7234 section 5.2.2.3</a>
*/
public static CacheControl noStore() {
CacheControl cc = new CacheControl();
cc.noStore = true;
return cc;
}
/**
* Add a "no-cache" directive.
*
* <p>This directive is well suited for telling caches that the response can be reused only if the client
* revalidates it with the server. This directive won't disable cache altogether and may result with
* clients sending conditional requests (with "ETag", "If-Modified-Since" headers) and the server responding
* with "304 - Not Modified" status.
*
* <p>In order to disable caching and minimize requests/responses exchanges, the {@link #noStore()} directive
* should be used.
*
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.2">rfc7234 section 5.2.2.2</a>
*/
public static CacheControl noCache() {
@@ -140,25 +121,23 @@ public class CacheControl {
}
/**
* Return an empty directive.
*
* <p>This is well suited for using other optional directives without "no-cache", "no-store" or "max-age".
*
* Add a "no-store" directive.
* <p>This directive is well suited for preventing caches (browsers and proxies) to cache the content of responses.
* @return {@code this}, to facilitate method chaining
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.3">rfc7234 section 5.2.2.3</a>
*/
public static CacheControl empty() {
public static CacheControl noStore() {
CacheControl cc = new CacheControl();
cc.noStore = true;
return cc;
}
/**
* Add a "must-revalidate" directive
*
* Add a "must-revalidate" directive.
* <p>This directive indicates that once it has become stale, a cache MUST NOT use the response
* to satisfy subsequent requests without successful validation on the origin server.
*
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.1">rfc7234 section 5.2.2.1</a>
*/
public CacheControl mustRevalidate() {
@@ -167,13 +146,10 @@ public class CacheControl {
}
/**
* Add a "no-transform" directive
*
* Add a "no-transform" directive.
* <p>This directive indicates that intermediaries (caches and others) should not transform the response content.
* This can be useful to force caches and CDNs not to automatically gzip or optimize the response content.
*
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.4">rfc7234 section 5.2.2.4</a>
*/
public CacheControl noTransform() {
@@ -182,13 +158,10 @@ public class CacheControl {
}
/**
* Add a "public" directive
*
* Add a "public" directive.
* <p>This directive indicates that any cache MAY store the response, even if the response
* would normally be non-cacheable or cacheable only within a private cache.
*
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.5">rfc7234 section 5.2.2.5</a>
*/
public CacheControl cachePublic() {
@@ -197,13 +170,10 @@ public class CacheControl {
}
/**
* Add a "private" directive
*
* Add a "private" directive.
* <p>This directive indicates that the response message is intended for a single user
* and MUST NOT be stored by a shared cache.
*
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.6">rfc7234 section 5.2.2.6</a>
*/
public CacheControl cachePrivate() {
@@ -212,13 +182,10 @@ public class CacheControl {
}
/**
* Add a "proxy-revalidate" directive
*
* Add a "proxy-revalidate" directive.
* <p>This directive has the same meaning as the "must-revalidate" directive,
* except that it does not apply to private caches (i.e. browsers, HTTP clients)
*
* except that it does not apply to private caches (i.e. browsers, HTTP clients).
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.7">rfc7234 section 5.2.2.7</a>
*/
public CacheControl proxyRevalidate() {
@@ -227,15 +194,12 @@ public class CacheControl {
}
/**
* Add a "s-maxage" directive
*
* Add an "s-maxage" directive.
* <p>This directive indicates that, in shared caches, the maximum age specified by this directive
* overrides the maximum age specified by other directives.
*
* @param sMaxAge the maximum time the response should be cached
* @param unit the time unit of the {@code sMaxAge} argument
* @return {@code this}, to facilitate method chaining
*
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2.2.9">rfc7234 section 5.2.2.9</a>
*/
public CacheControl sMaxAge(long sMaxAge, TimeUnit unit) {
@@ -243,15 +207,15 @@ public class CacheControl {
return this;
}
/**
* Return the "Cache-Control" header value
*
* @return null if no directive was added, the header value otherwise
* Return the "Cache-Control" header value.
* @return {@code null} if no directive was added, or the header value otherwise
*/
public String getHeaderValue() {
StringBuilder ccValue = new StringBuilder();
if (this.maxAge != -1) {
appendDirective(ccValue, "max-age=" + Long.toString(maxAge));
appendDirective(ccValue, "max-age=" + Long.toString(this.maxAge));
}
if (this.noCache) {
appendDirective(ccValue, "no-cache");
@@ -278,17 +242,14 @@ public class CacheControl {
appendDirective(ccValue, "s-maxage=" + Long.toString(this.sMaxAge));
}
String ccHeaderValue = ccValue.toString();
if (StringUtils.hasText(ccHeaderValue)) {
return ccHeaderValue;
}
return null;
return (StringUtils.hasText(ccHeaderValue) ? ccHeaderValue : null);
}
private void appendDirective(StringBuilder b, String value) {
if (b.length() > 0) {
b.append(", ");
private void appendDirective(StringBuilder builder, String value) {
if (builder.length() > 0) {
builder.append(", ");
}
b.append(value);
builder.append(value);
}
}

6
spring-web/src/main/java/org/springframework/http/ResponseEntity.java
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@@ -321,14 +321,14 @@ public class ResponseEntity<T> extends HttpEntity<T> {
B location(URI location);
/**
* Set the caching directives for the resource, as specified by the
* Set the caching directives for the resource, as specified by the HTTP 1.1
* {@code Cache-Control} header.
* <p>A {@code CacheControl} instance can be built like
* {@code CacheControl.maxAge(3600).cachePublic().noTransform()}.
* @param cacheControl the instance that builds cache related HTTP response headers
* @param cacheControl a builder for cache-related HTTP response headers
* @return this builder
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2">RFC-7234 Section 5.2</a>
* @since 4.2
* @see <a href="https://tools.ietf.org/html/rfc7234#section-5.2">RFC-7234 Section 5.2</a>
*/
B cacheControl(CacheControl cacheControl);