Spring Security許可權框架理論與實戰(五)- 自定義決策

摘要： AbstractAccessDecisionManager 核心方法 其中的決策類型別-投票器 看一下最常見的投票器 定義了...

AbstractAccessDecisionManager

核心方法

其中的決策類型別-投票器

看一下最常見的投票器

核心方法自然為選舉方法

三大投票器

AffirmativeBased

一票通過

/**
 * Simple concrete implementation of
 * {@link org.springframework.security.access.AccessDecisionManager} that grants access if
 * any <code>AccessDecisionVoter</code> returns an affirmative response.
 */
public class AffirmativeBased extends AbstractAccessDecisionManager {

public AffirmativeBased(List<AccessDecisionVoter<? extends Object>> decisionVoters) {
super(decisionVoters);
}

// ~ Methods
// ========================================================================================================

/**
* This concrete implementation simply polls all configured
* {@link AccessDecisionVoter}s and grants access if any
* <code>AccessDecisionVoter</code> voted affirmatively. Denies access only if there
* was a deny vote AND no affirmative votes.
* <p>
* If every <code>AccessDecisionVoter</code> abstained from voting, the decision will
* be based on the {@link #isAllowIfAllAbstainDecisions()} property (defaults to
* false).
* </p>
*
* @param authentication the caller invoking the method
* @param object the secured object
* @param configAttributes the configuration attributes associated with the method
* being invoked
*
* @throws AccessDeniedException if access is denied
*/
public void decide(Authentication authentication, Object object,
Collection<ConfigAttribute> configAttributes) throws AccessDeniedException {
int deny = 0;

for (AccessDecisionVoter voter : getDecisionVoters()) {
int result = voter.vote(authentication, object, configAttributes);

if (logger.isDebugEnabled()) {
logger.debug("Voter: " + voter + ", returned: " + result);
}

switch (result) {
case AccessDecisionVoter.ACCESS_GRANTED:
return;

case AccessDecisionVoter.ACCESS_DENIED:
deny++;

break;

default:
break;
}
}

if (deny > 0) {
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied", "Access is denied"));
}

// To get this far, every AccessDecisionVoter abstained
checkAllowIfAllAbstainDecisions();
}
}

ConsensusBased

一半以上功能選舉通過

/**
 * Simple concrete implementation of
 * {@link org.springframework.security.access.AccessDecisionManager} that uses a
 * consensus-based approach.
 * <p>
 * "Consensus" here means majority-rule (ignoring abstains) rather than unanimous
 * agreement (ignoring abstains). If you require unanimity, please see
 * {@link UnanimousBased}.
 */
public class ConsensusBased extends AbstractAccessDecisionManager {
// ~ Instance fields
// ================================================================================================

private boolean allowIfEqualGrantedDeniedDecisions = true;

public ConsensusBased(List<AccessDecisionVoter<? extends Object>> decisionVoters) {
super(decisionVoters);
}

// ~ Methods
// ========================================================================================================

/**
* This concrete implementation simply polls all configured
* {@link AccessDecisionVoter}s and upon completion determines the consensus of
* granted against denied responses.
* <p>
* If there were an equal number of grant and deny votes, the decision will be based
* on the {@link #isAllowIfEqualGrantedDeniedDecisions()} property (defaults to true).
* <p>
* If every <code>AccessDecisionVoter</code> abstained from voting, the decision will
* be based on the {@link #isAllowIfAllAbstainDecisions()} property (defaults to
* false).
*
* @param authentication the caller invoking the method
* @param object the secured object
* @param configAttributes the configuration attributes associated with the method
* being invoked
*
* @throws AccessDeniedException if access is denied
*/
public void decide(Authentication authentication, Object object,
Collection<ConfigAttribute> configAttributes) throws AccessDeniedException {
int grant = 0;
int deny = 0;
int abstain = 0;

for (AccessDecisionVoter voter : getDecisionVoters()) {
int result = voter.vote(authentication, object, configAttributes);

if (logger.isDebugEnabled()) {
logger.debug("Voter: " + voter + ", returned: " + result);
}

switch (result) {
case AccessDecisionVoter.ACCESS_GRANTED:
grant++;

break;

case AccessDecisionVoter.ACCESS_DENIED:
deny++;

break;

default:
abstain++;

break;
}
}

if (grant > deny) {
return;
}

if (deny > grant) {
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied", "Access is denied"));
}

if ((grant == deny) && (grant != 0)) {
if (this.allowIfEqualGrantedDeniedDecisions) {
return;
}
else {
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied", "Access is denied"));
}
}

// To get this far, every AccessDecisionVoter abstained
checkAllowIfAllAbstainDecisions();
}

public boolean isAllowIfEqualGrantedDeniedDecisions() {
return allowIfEqualGrantedDeniedDecisions;
}

public void setAllowIfEqualGrantedDeniedDecisions(
boolean allowIfEqualGrantedDeniedDecisions) {
this.allowIfEqualGrantedDeniedDecisions = allowIfEqualGrantedDeniedDecisions;
}
}

UnanimousBased

全票通過才可

/**
 * Simple concrete implementation of
 * {@link org.springframework.security.access.AccessDecisionManager} that requires all
 * voters to abstain or grant access.
 */
public class UnanimousBased extends AbstractAccessDecisionManager {

public UnanimousBased(List<AccessDecisionVoter<? extends Object>> decisionVoters) {
super(decisionVoters);
}

// ~ Methods
// ========================================================================================================

/**
* This concrete implementation polls all configured {@link AccessDecisionVoter}s for
* each {@link ConfigAttribute} and grants access if <b>only</b> grant (or abstain)
* votes were received.
* <p>
* Other voting implementations usually pass the entire list of
* <tt>ConfigAttribute</tt>s to the <code>AccessDecisionVoter</code>. This
* implementation differs in that each <code>AccessDecisionVoter</code> knows only
* about a single <code>ConfigAttribute</code> at a time.
* <p>
* If every <code>AccessDecisionVoter</code> abstained from voting, the decision will
* be based on the {@link #isAllowIfAllAbstainDecisions()} property (defaults to
* false).
*
* @param authentication the caller invoking the method
* @param object the secured object
* @param attributes the configuration attributes associated with the method being
* invoked
*
* @throws AccessDeniedException if access is denied
*/
public void decide(Authentication authentication, Object object,
Collection<ConfigAttribute> attributes) throws AccessDeniedException {

int grant = 0;
int abstain = 0;

List<ConfigAttribute> singleAttributeList = new ArrayList<>(1);
singleAttributeList.add(null);

for (ConfigAttribute attribute : attributes) {
singleAttributeList.set(0, attribute);

for (AccessDecisionVoter voter : getDecisionVoters()) {
int result = voter.vote(authentication, object, singleAttributeList);

if (logger.isDebugEnabled()) {
logger.debug("Voter: " + voter + ", returned: " + result);
}

switch (result) {
case AccessDecisionVoter.ACCESS_GRANTED:
grant++;

break;

case AccessDecisionVoter.ACCESS_DENIED:
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied",
"Access is denied"));

default:
abstain++;

break;
}
}
}

// To get this far, there were no deny votes
if (grant > 0) {
return;
}

// To get this far, every AccessDecisionVoter abstained
checkAllowIfAllAbstainDecisions();
}
}