{"id":1996,"date":"2019-10-24T08:00:22","date_gmt":"2019-10-24T00:00:22","guid":{"rendered":"https:\/\/coderbee.net\/?p=1996"},"modified":"2019-10-23T21:42:02","modified_gmt":"2019-10-23T13:42:02","slug":"mybatis-%e7%bc%93%e5%ad%98","status":"publish","type":"post","link":"https:\/\/coderbee.net\/index.php\/framework\/20191024\/1996","title":{"rendered":"MyBatis \u7f13\u5b58"},"content":{"rendered":"<p>\u6240\u6709 <code>insert\/update\/delete<\/code> \u8bed\u53e5\u90fd\u4f1a\u5bfc\u81f4\u7f13\u5b58\u88ab\u6e05\u9664\u3002<\/p>\n<h2>1. \u4e00\u7ea7\u7f13\u5b58<\/h2>\n<p>\u4e00\u7ea7\u7f13\u5b58\u662f\u9488\u5bf9\u6570\u636e\u5e93\u4f1a\u8bdd\u7684\uff0c\u7528\u4e8e\u4f18\u5316\u5728\u4e00\u6b21\u6570\u636e\u5e93\u4f1a\u8bdd\u91cc\u591a\u6b21\u6267\u884c\u540c\u6837\u7684 SQL\u3002<\/p>\n<p>\u6709\u4e24\u79cd\u8303\u56f4\uff1a<\/p>\n<ul>\n<li>SESSION\uff1a\u4f1a\u8bdd\u7ea7\uff0c\u9ed8\u8ba4\u7684\u3002<\/li>\n<li>STATEMENT\uff1a\u8bed\u53e5\u7ea7\uff0c\u6bcf\u6b21\u6267\u884c\u5b8c mapper \u4e2d\u7684\u8bed\u53e5\u540e\u90fd\u6e05\u9664\u4e00\u7ea7\u7f13\u5b58\uff0c\u5176\u5b9e\u5c31\u662f\u7981\u7528\u8fd9\u4e2a\u8bed\u53e5\u7684\u4e00\u7ea7\u7f13\u5b58\u3002<\/li>\n<\/ul>\n<p>\u5982\u679c\u8981\u5728\u5168\u5c40\u66f4\u6539\u4e00\u7ea7\u7f13\u5b58\u7684\u8303\u56f4\uff0c\u9700\u8981\u5728 MyBatis \u7684\u914d\u7f6e\u6587\u4ef6\u4e2d\u8bbe\u7f6e\uff1a<\/p>\n<pre><code class=\"xml\">&lt;setting name=\"localCacheScope\" value=\"STATEMENT\"\/&gt;\n<\/code><\/pre>\n<h2>2. \u4e8c\u7ea7\u7f13\u5b58<\/h2>\n<p>\u4e8c\u7ea7\u7f13\u5b58\u662f\u9488\u5bf9 Mapper \u7ea7\u522b\u7684\uff0c\u9ed8\u8ba4\u662f\u542f\u7528\u7684\uff0c\u4f46\u751f\u6548\u7684\u8bdd\u8981\u5bf9\u6bcf\u4e2a Mapper \u8fdb\u884c\u914d\u7f6e\uff0cMapper \u91cc\u6ca1\u6709\u914d\u7f6e\u7684\u4e0d\u4f7f\u7528\u4e8c\u7ea7\u7f13\u5b58\u3002<\/p>\n<p><strong>\u6ce8\u610f\uff1a<\/strong>\u5982\u679c\u5728\u591a\u4e2a Mapper \u4e2d\u5b58\u5728\u5bf9\u540c\u4e00\u4e2a\u8868\u7684\u64cd\u4f5c\uff0c\u90a3\u4e48\u8fd9\u51e0\u4e2a Mapper \u7684\u7f13\u5b58\u6570\u636e\u53ef\u80fd\u4f1a\u51fa\u73b0\u4e0d\u4e00\u81f4\u73b0\u8c61\u3002<\/p>\n<pre><code class=\"xml\">&lt;!-- \u4e0d\u542f\u7528\u7684\u8bdd\u5728\u914d\u7f6e\u6587\u4ef6\u4e2d\u6307\u5b9a\u5982\u4e0b --&gt;\n&lt;settings&gt;\n&lt;setting name=\"cacheEnabled\" value=\"false\" \/&gt;\n&lt;\/settings&gt;\n\n\n&lt;!-- Mapper \u6587\u4ef6\u91cc\u914d\u7f6e cache \u5143\u7d20\u4ee5\u751f\u6548 --&gt;\n&lt;mapper namespace=\"...UserMapper\"&gt;\n    &lt;!-- \u9ed8\u8ba4\u5bf9\u8be5 Mapper \u6587\u4ef6\u91cc\u7684\u6240\u6709\u67e5\u8be2\u4f7f\u7528\u4e8c\u7ea7\u7f13\u5b58 --&gt;\n    &lt;cache\/&gt;\n\n    &lt;!-- \u8be5select\u8bed\u53e5\u4e0d\u4f7f\u7528\u7f13\u5b58 --&gt;\n    &lt;select id=\"selectAbc\" useCache=\"false\"&gt;\n        ...\n    &lt;\/select&gt;\n&lt;\/mapper&gt;\n<\/code><\/pre>\n<h1>3. \u6e90\u7801\u5b9e\u73b0<\/h1>\n<p><!--more--><\/p>\n<h2>3.1 \u4e00\u7ea7\u7f13\u5b58\u5b9e\u73b0<\/h2>\n<p>\u4e00\u7ea7\u7f13\u5b58\u901a\u8fc7 <code>BaseExecutor<\/code> \u7684 <code>localCache<\/code> \u5c5e\u6027\u5b9e\u73b0\u3002<\/p>\n<pre><code class=\"java\">public abstract class BaseExecutor implements Executor {\n  protected PerpetualCache localCache;\n\n  public &lt;E&gt; List&lt;E&gt; query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler) throws SQLException {\n    BoundSql boundSql = ms.getBoundSql(parameter);\n    CacheKey key = createCacheKey(ms, parameter, rowBounds, boundSql);\n    return query(ms, parameter, rowBounds, resultHandler, key, boundSql);\n  }\n\n  public &lt;E&gt; List&lt;E&gt; query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql) throws SQLException {\n    ErrorContext.instance().resource(ms.getResource()).activity(\"executing a query\").object(ms.getId());\n    if (closed) {\n      throw new ExecutorException(\"Executor was closed.\");\n    }\n    if (queryStack == 0 &amp;&amp; ms.isFlushCacheRequired()) {\n      clearLocalCache();\n    }\n    List&lt;E&gt; list;\n    try {\n      queryStack++;\n      list = resultHandler == null ? (List&lt;E&gt;) localCache.getObject(key) : null;\n      if (list != null) {\n        handleLocallyCachedOutputParameters(ms, key, parameter, boundSql);\n      } else {\n        list = queryFromDatabase(ms, parameter, rowBounds, resultHandler, key, boundSql);\n      }\n    } finally {\n      queryStack--;\n    }\n    if (queryStack == 0) {\n      for (DeferredLoad deferredLoad : deferredLoads) {\n        deferredLoad.load();\n      }\n      \/\/ issue #601\n      deferredLoads.clear();\n      if (configuration.getLocalCacheScope() == LocalCacheScope.STATEMENT) {\n        \/\/ \u7f13\u5b58\u57fa\u672c\u662f STATEMENT \u7684\uff0c\u5728\u6267\u884c\u5b8c\u540e\u6e05\u9664\u7f13\u5b58\u3002\n        \/\/ issue #482\n        clearLocalCache();\n      }\n    }\n    return list;\n  }\n\n  private &lt;E&gt; List&lt;E&gt; queryFromDatabase(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql) throws SQLException {\n    List&lt;E&gt; list;\n    localCache.putObject(key, EXECUTION_PLACEHOLDER);\n    try {\n      list = doQuery(ms, parameter, rowBounds, resultHandler, boundSql);\n    } finally {\n      localCache.removeObject(key);\n    }\n    localCache.putObject(key, list);\n    if (ms.getStatementType() == StatementType.CALLABLE) {\n      localOutputParameterCache.putObject(key, parameter);\n    }\n    return list;\n  }\n\n    public void commit(boolean required) throws SQLException {\n        if (closed) {\n            throw new ExecutorException(\"Cannot commit, transaction is already closed\");\n        }\n        \/\/ \u4e8b\u52a1\u63d0\u4ea4\u65f6\u6e05\u7406\u4e00\u7ea7\u7f13\u5b58\n        clearLocalCache();\n        flushStatements();\n        if (required) {\n            transaction.commit();\n        }\n    }\n\n}\n<\/code><\/pre>\n<h2>3.2 \u4e8c\u7ea7\u7f13\u5b58\u5b9e\u73b0<\/h2>\n<p>\u4e8c\u7ea7\u7f13\u5b58\u901a\u8fc7 CachingExecutor \u548c MappedStatement \u5173\u8054\u7684 cache \u5bf9\u8c61\u6765\u5b9e\u73b0\u3002<\/p>\n<p>\u4e8c\u7ea7\u7f13\u5b58\u7684\u7279\u70b9\u662f\u8ddf\u4e8b\u52a1\u76f8\u5173\uff0c\u4e8b\u52a1\u63d0\u4ea4\u6210\u529f\u4e86\u7f13\u5b58\u624d\u751f\u6548\uff0c\u4e8b\u52a1\u56de\u6eda\u6216\u4e0d\u63d0\u4ea4\u5219\u7f13\u5b58\u4e0d\u751f\u6548\uff1b\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u67e5\u8be2\u5f97\u5230\u7684\u6570\u636e\u5c01\u88c5\u5728 <code>TransactionalCache<\/code>\uff0c\u7531 <code>TransactionalCacheManager<\/code> \u7ef4\u62a4\uff0c<code>CachingExecutor<\/code> \u4f1a\u5728\u4e8b\u52a1\u63d0\u4ea4\u3001\u56de\u6eda\u7684\u5730\u65b9\u8c03\u7528 <code>TransactionalCacheManager<\/code> \u7684\u65b9\u6cd5\u6765\u63a7\u5236\u4e8b\u52a1\u6027\u7f13\u5b58\u662f\u5426\u63d0\u4ea4\u5230\u4e8c\u7ea7\u7f13\u5b58\u3002<\/p>\n<pre><code class=\"java\">public class Configuration {\n    protected boolean cacheEnabled = true; \/\/ \u9ed8\u8ba4\u542f\u7528\u4e8c\u7ea7\u7f13\u5b58\n\n    \/\/ \u6bcf\u4e2a SqlSession \u4f1a\u6301\u6709\u4e00\u4e2a Executor\n    public Executor newExecutor(Transaction transaction, ExecutorType executorType) {\n        executorType = executorType == null ? defaultExecutorType : executorType;\n        executorType = executorType == null ? ExecutorType.SIMPLE : executorType;\n        Executor executor;\n        if (ExecutorType.BATCH == executorType) {\n            executor = new BatchExecutor(this, transaction);\n        } else if (ExecutorType.REUSE == executorType) {\n            executor = new ReuseExecutor(this, transaction);\n        } else {\n            executor = new SimpleExecutor(this, transaction);\n        }\n        if (cacheEnabled) {\n            \/\/ \u542f\u7528\u4e86\u4e8c\u7ea7\u7f13\u5b58\u7684\uff0c\u7528 CachingExecutor \u5305\u88c5\u5177\u4f53\u7684 Executor\n            executor = new CachingExecutor(executor);\n        }\n        executor = (Executor) interceptorChain.pluginAll(executor);\n        return executor;\n    }\n}\n<\/code><\/pre>\n<p><code>CachingExecutor<\/code> \u7ef4\u62a4\u4e8c\u7ea7\u7f13\u5b58\u3002<\/p>\n<pre><code class=\"java\">public class CachingExecutor implements Executor {\n  private Executor delegate;\n  \/\/ \u7ba1\u7406\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u4ea7\u751f\u7684\u67e5\u8be2\u6570\u636e\n  private TransactionalCacheManager tcm = new TransactionalCacheManager();\n\n  public &lt;E&gt; List&lt;E&gt; query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler   resultHandler) throws SQLException {\n    BoundSql boundSql = ms.getBoundSql(parameterObject);\n    CacheKey key = createCacheKey(ms, parameterObject, rowBounds, boundSql);\n    return query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);\n  }\n\n  public &lt;E&gt; List&lt;E&gt; query(MappedStatement ms, Object parameterObject, RowBounds rowBounds, ResultHandler resultHandler, CacheKey key, BoundSql boundSql) throws SQLException {\n    Cache cache = ms.getCache();\n    if (cache != null) { \/\/ Mapper \u914d\u7f6e\u4e86 cache \u624d\u8d77\u4f5c\u7528\n      flushCacheIfRequired(ms);\n      if (ms.isUseCache() &amp;&amp; resultHandler == null) {\n        ensureNoOutParams(ms, parameterObject, boundSql);\n        @SuppressWarnings(\"unchecked\")\n        List&lt;E&gt; list = (List&lt;E&gt;) tcm.getObject(cache, key);\n        if (list == null) {\n          list = delegate.&lt;E&gt; query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);\n          \/\/ \u6b64\u65f6\u53ea\u662f\u628a\u6570\u636e\u6dfb\u52a0\u5230\u7b49\u5f85\u63d0\u4ea4\u7684\u72b6\u6001\n          tcm.putObject(cache, key, list); \/\/ issue #578 and #116\n        }\n        return list;\n      }\n    }\n    return delegate.&lt;E&gt; query(ms, parameterObject, rowBounds, resultHandler, key, boundSql);\n  }\n\n    public void commit(boolean required) throws SQLException {\n        \/\/ \u63d0\u4ea4\u6570\u636e\u5e93\u4e8b\u52a1\n        delegate.commit(required);\n\n        \/\/ \u63d0\u4ea4\u7f13\u5b58\n        tcm.commit();\n    }\n\n    public void rollback(boolean required) throws SQLException {\n        try {\n            delegate.rollback(required);\n        }finally {\n            if (required) {\n                \/\/ \n                tcm.rollback();\n            }\n        }\n    }\n}\n<\/code><\/pre>\n<p>\u6ce8\u610f\uff1a\u4e0a\u9762\u7684 <code>Cache cache = ms.getCache();<\/code> \u6807\u660e\u8fd9\u4e2a cache \u662f\u8ddf\u968f MappedStatement \u7684\uff0c\u591a\u4e2a SqlSession \u6267\u884c\u540c\u4e00\u4e2a MappedStatement \u65f6\u5c31\u80fd\u5171\u4eab\u8fd9\u4e2a\u7f13\u5b58\u3002<\/p>\n<p>\u4e00\u6b21\u4e8b\u52a1\u64cd\u4f5c\u53ef\u80fd\u6d89\u53ca\u591a\u4e2a Mapper \u7684\u7f13\u5b58\uff0c<code>TransactionalCacheManager<\/code> \u7ef4\u62a4\u4e86\u591a\u4e2a Mapper \u7f13\u5b58\u53ca\u5176\u4e8b\u52a1\u6027\u7f13\u5b58\u7684\u5173\u7cfb\u3002<\/p>\n<pre><code class=\"java\">public class TransactionalCacheManager {\n    \/\/ Cache \u662f Mapper \u7684\u4e8c\u7ea7\u7f13\u5b58\uff0c\n    private Map&lt;Cache, TransactionalCache&gt; transactionalCaches = new HashMap&lt;Cache, TransactionalCache&gt;();\n\n    public Object getObject(Cache cache, CacheKey key) {\n        return getTransactionalCache(cache).getObject(key);\n    }\n    public void commit() {\n        for (TransactionalCache txCache : transactionalCaches.values()) {\n            txCache.commit();\n        }\n    }\n\n    private TransactionalCache getTransactionalCache(Cache cache) {\n        TransactionalCache txCache = transactionalCaches.get(cache);\n        if (txCache == null) {\n            \/\/ \u7528 \u76ee\u6807\u7f13\u5b58 \u521d\u59cb\u5316\u4e8b\u52a1\u6027\u7f13\u5b58\n            txCache = new TransactionalCache(cache);\n            transactionalCaches.put(cache, txCache);\n        }\n        return txCache;\n    }\n}\n<\/code><\/pre>\n<p><code>TransactionalCache<\/code> \u4e8b\u52a1\u6027\u7f13\u5b58\uff0c\u6301\u6709\u5bf9\u76ee\u6807\u7f13\u5b58\u7684\u5f15\u7528\uff0c\u6839\u636e\u4e8b\u52a1\u662f\u5426\u63d0\u4ea4\u6765\u51b3\u5b9a\u662f\u5426\u63d0\u4ea4\u5230\u76ee\u6807\u7f13\u5b58\u3002\u4e8b\u52a1\u7ed3\u675f\u540e\u603b\u4f1a\u88ab\u6e05\u7a7a\u3002<\/p>\n<pre><code class=\"java\">public class TransactionalCache implements Cache {\n    private Cache delegate;\n    private boolean clearOnCommit;\n    private Map&lt;Object, Object&gt; entriesToAddOnCommit;\n    private Set&lt;Object&gt; entriesMissedInCache;\n\n    public TransactionalCache(Cache delegate) {\n        this.delegate = delegate;\n        this.clearOnCommit = false;\n        this.entriesToAddOnCommit = new HashMap&lt;Object, Object&gt;();\n        this.entriesMissedInCache = new HashSet&lt;Object&gt;();\n    }\n\n    public void commit() {\n        if (clearOnCommit) {\n            delegate.clear();\n        }\n        flushPendingEntries();  \/\/ \u63d0\u4ea4\u5230\u76ee\u6807\u7f13\u5b58\n        reset();                \/\/ \u6e05\u7a7a\n    }\n\n    private void flushPendingEntries() {\n        for (Map.Entry&lt;Object, Object&gt; entry : entriesToAddOnCommit.entrySet()) {\n            delegate.putObject(entry.getKey(), entry.getValue());\n        }\n        for (Object entry : entriesMissedInCache) {\n            if (!entriesToAddOnCommit.containsKey(entry)) {\n                delegate.putObject(entry, null);\n            }\n        }\n    }\n\n    private void reset() {\n        clearOnCommit = false;\n        entriesToAddOnCommit.clear();\n        entriesMissedInCache.clear();\n    }\n}\n<\/code><\/pre>\n<p>\u4e8c\u7ea7\u7f13\u5b58\u4e3a\u4ec0\u4e48\u8981\u5148\u5c01\u88c5\u5728 TransactionalCache\u3001\u8ddf\u968f\u4e8b\u52a1\u63d0\u4ea4\u800c\u63d0\u4ea4\uff1f<br \/>\n\u56e0\u4e3a\u4e8b\u52a1\u91cc\u53ef\u80fd\u5148\u4fee\u6539\u4e86\u6570\u636e\u3001\u7136\u540e\u67e5\u8be2\u51fa\u6700\u65b0\u7684\u6570\u636e\uff0c\u56e0\u6b64\u5fc5\u987b\u662f\u4e8b\u52a1\u63d0\u4ea4\u4e86\u624d\u80fd\u63d0\u4ea4\u5230\u4e8c\u7ea7\u7f13\u5b58\uff0c\u5426\u5219\u4e8b\u52a1\u672a\u63d0\u4ea4\u6216\u4e8b\u52a1\u56de\u6eda\u3001\u5176\u4ed6\u4f1a\u8bdd\u53ef\u80fd\u4f1a\u770b\u5230\u810f\u6570\u636e\u3002<\/p>\n<h1>4. \u7f13\u5b58\u5b58\u50a8<\/h1>\n<h2>4.1 \u5b58\u50a8\u5c5e\u6027\u914d\u7f6e<\/h2>\n<p>\u7f13\u5b58\u5143\u7d20\u53ef\u4ee5\u8fd9\u6837\u914d\u7f6e\uff1a<br \/>\n<code>&lt;cache eviction=\"LRU\" flushInterval=\"60000\" size=\"1024\" readOnly=\"true\" \/&gt;<\/code><\/p>\n<p>\u5176\u5c5e\u6027\u542b\u4e49\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>\n<p><code>eviction<\/code>\uff1a\u7f13\u5b58\u7684\u6dd8\u6c70\u7b97\u6cd5\uff0c\u53ef\u9009\u503c\u6709&#8221;LRU&#8221;\u3001&#8221;FIFO&#8221;\u3001&#8221;SOFT&#8221;\u3001&#8221;WEAK&#8221;\uff0c\u7f3a\u7701\u503c\u662fLRU\u3002<\/p>\n<\/li>\n<li>\n<p><code>flashInterval<\/code>\uff1a\u6307\u7f13\u5b58\u8fc7\u671f\u65f6\u95f4\uff0c\u5355\u4f4d\u4e3a\u6beb\u79d2\uff0c60000\u5373\u4e3a60\u79d2\uff0c\u7f3a\u7701\u503c\u4e3a\u7a7a\uff0c\u5373\u53ea\u8981\u5bb9\u91cf\u8db3\u591f\uff0c\u6c38\u4e0d\u8fc7\u671f\u3002<\/p>\n<\/li>\n<li>\n<p><code>size<\/code>\uff1a\u6307\u7f13\u5b58\u591a\u5c11\u4e2a\u5bf9\u8c61\uff0c\u9ed8\u8ba4\u503c\u4e3a<code>1024<\/code> \u3002<\/p>\n<\/li>\n<li>\n<p><code>readOnly<\/code>\uff1a\u662f\u5426\u53ea\u8bfb\uff0c\u5982\u679c\u4e3a<code>true<\/code>\uff0c\u5219\u6240\u6709\u76f8\u540c\u7684sql\u8bed\u53e5\u8fd4\u56de\u7684\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\uff08\u6709\u52a9\u4e8e\u63d0\u9ad8\u6027\u80fd\uff0c\u4f46\u5e76\u53d1\u64cd\u4f5c\u540c\u4e00\u6761\u6570\u636e\u65f6\uff0c\u53ef\u80fd\u4e0d\u5b89\u5168\uff09\uff0c\u5982\u679c\u8bbe\u7f6e\u4e3a<code>false<\/code>\uff0c\u5219\u76f8\u540c\u7684sql\uff0c\u540e\u9762\u8bbf\u95ee\u7684\u662fcache\u7684\u514b\u9686\u526f\u672c\u3002<\/p>\n<\/li>\n<\/ul>\n<h2>4.2 \u5e95\u5c42\u5b58\u50a8\u5b9e\u73b0<\/h2>\n<p>PerpetualCache\uff1a\u76f4\u63a5\u5c01\u88c5\u4e86 HashMap \u4f5c\u4e3a\u5b58\u50a8\uff0c\u65e0\u9650\u5bb9\u91cf\u3002<\/p>\n<p>\u5305\u88c5\u5668\u7f13\u5b58\uff1a\u5c01\u88c5\u4e86\u5176\u4ed6\u7684 Cache \u5b9e\u73b0\uff0c\u63d0\u4f9b\u989d\u5916\u7684\u903b\u8f91\u3002<\/p>\n<ul>\n<li>\n<p>BlockingCache\uff1a\u4e3a\u6bcf\u4e2a key \u5206\u914d\u4e00\u4e2a ReentrantLock \u9501\uff0c\u8bbf\u95ee key \u8981\u5728\u6301\u6709\u9501\u7684\u524d\u63d0\u4e0b\u8fdb\u884c\u3002<\/p>\n<\/li>\n<li>\n<p>FifoCache\uff1a\u7f13\u5b58\u5bb9\u91cf\u6ee1\u65f6\u9075\u5faa FIFO \u6e05\u9664\u6700\u8001\u7684 key \u3002\u501f\u52a9 LinkedList \u6765\u5b9e\u73b0 FIFO \u961f\u5217\u3002<\/p>\n<\/li>\n<li>\n<p>LoggingCache\uff1a\u6bcf\u6b21\u8bbf\u95ee key \u65f6\u53ef\u4ee5\u8f93\u51fa\u7f13\u5b58\u7684\u547d\u4e2d\u7387\u7684\u7f13\u5b58\u3002\u7ef4\u62a4\u4e86\u5bf9\u7f13\u5b58\u7684\u8bf7\u6c42\u6b21\u6570\u3001\u547d\u4e2d\u6b21\u6570\u3002<\/p>\n<\/li>\n<li>\n<p>LruCache\uff1a\u5229\u7528 LinkedHashMap \u6765\u5b9e\u73b0 \u6700\u8fd1\u6700\u5c11\u4f7f\u7528 \u7684\u7279\u6027\u3002<\/p>\n<\/li>\n<li>\n<p>ScheduledCache\uff1a\u5b9e\u73b0\u4e86\u5b9a\u671f\u6e05\u9664\u6240\u6709 key \u7684\u7279\u6027\u3002\u5728\u6bcf\u6b21\u8bbf\u95ee\u65f6\u5224\u65ad\u662f\u5426\u9700\u8981\u5148\u6e05\u9664\u3002\u7ef4\u62a4\u4e86\u6700\u8fd1\u6e05\u9664\u65f6\u95f4\u3001\u6e05\u9664\u95f4\u9694\u3002<\/p>\n<\/li>\n<li>\n<p>SerializedCache\uff1a\u628a\u503c\u5e8f\u5217\u5316\u4e3a\u5b57\u8282\u6570\u7ec4\u6765\u5b58\u50a8\u7684\u7f13\u5b58\u3002<\/p>\n<\/li>\n<li>\n<p>SynchronizedCache\uff1a\u57fa\u4e8e synchronized \u5173\u952e\u5b57\u6765\u5b9e\u73b0\u7684\u7ebf\u7a0b\u5b89\u5168\u7684\u7f13\u5b58\u3002<\/p>\n<\/li>\n<li>\n<p>TransactionalCache\uff1a\u63d0\u4f9b\u4e86 commit\/rollback \u65b9\u6cd5\u7684\u53ef\u4e0e\u4e8b\u52a1\u534f\u4f5c\u7684\u7f13\u5b58\uff0c\u662f\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u7684\u6570\u636e\u7684\u4e34\u65f6\u5b58\u50a8\uff0c\u4e8b\u52a1\u63d0\u4ea4\u540e\u624d\u63d0\u4ea4\u5230\u76ee\u6807\u7f13\u5b58\u3002<\/p>\n<\/li>\n<li>\n<p>SoftCache\uff1a\u628a\u952e\u503c\u5c01\u88c5\u5728 SoftReference \u7684\u5b50\u7c7b\uff0c\u5229\u7528\u8f6f\u5f15\u7528\u961f\u5217 ReferenceQueue \u6765\u8ddf\u8e2a\u88ab\u56de\u6536\u7684 key\uff0c\u6bcf\u6b21\u8bbf\u95ee\u5e95\u5c42\u7f13\u5b58\u4e4b\u524d\u5148\u6e05\u7406\u88ab\u56de\u6536\u7684\u7f13\u5b58\u6761\u76ee\u3002\u5229\u7528 LinkedList \u4fdd\u6301\u5bf9\u4e00\u5b9a\u7684\u7f13\u5b58\u6761\u76ee\u7684\u5f3a\u5f15\u7528\uff0c\u9632\u6b62\u5176\u88ab GC\u3002<\/p>\n<\/li>\n<li>\n<p>WeakCache\uff1a\u4e0e SoftCache \u7c7b\u4f3c\uff0c\u53ea\u662f\u628a\u952e\u503c\u5c01\u88c5\u5728 WeakReference \u7684\u5b50\u7c7b\u3002<\/p>\n<\/li>\n<\/ul>\n<pre><code class=\"java\">private static class SoftEntry extends SoftReference&lt;Object&gt; {\n    private final Object key;\n\n    SoftEntry(Object key, Object value, ReferenceQueue&lt;Object&gt; garbageCollectionQueue) {\n        super(value, garbageCollectionQueue);\n        this.key = key;\n    }\n}\n<\/code><\/pre>\n<h1>5. \u5c0f\u7ed3<\/h1>\n<p>MyBatis \u7684\u7f13\u5b58\u9ed8\u8ba4\u662f\u91c7\u7528\u672c\u5730\u7f13\u5b58\uff0c\u5728\u76ee\u524d\u5e94\u7528\u7a0b\u5e8f\u4e00\u822c\u91c7\u7528\u591a\u5b9e\u4f8b\u3001\u5206\u5e03\u5f0f\u90e8\u7f72\u7684\u60c5\u51b5\u4e0b\uff0c\u5bb9\u6613\u51fa\u73b0\u810f\u6570\u636e\uff0c\u5c3d\u91cf\u4e0d\u8981\u4f7f\u7528\u5176\u7f13\u5b58\uff0c\u5982\u679c\u8981\u4f7f\u7528\uff0c\u5c3d\u91cf\u4f7f\u7528\u96c6\u4e2d\u5f0f\u7f13\u5b58\u3002<\/p>\n<p>\u4e8c\u7ea7\u7f13\u5b58\u662f\u9488\u5bf9 Mapper \u7684 namespace \u7684\uff0c\u5c3d\u91cf\u4fdd\u8bc1\u5bf9\u4e00\u5f20\u8868\u7684\u8bbf\u95ee\u53ea\u5728\u4e00\u4e2a Mapper \u91cc\u3002\u5426\u5219 Mapper A \u5173\u8054\u7684\u7f13\u5b58\u7f13\u5b58\u4e86 T \u8868\u7684\u67e5\u8be2\u6570\u636e\uff0c Mapper B \u5bf9 T \u8868\u8fdb\u884c\u66f4\u65b0\uff0c\u5bfc\u81f4 A \u7684\u7f13\u5b58\u6570\u636e\u53d8\u6210\u810f\u6570\u636e\u3002<\/p>\n<p>\u4e4b\u524d\u78b0\u5230\u7684\u4e00\u4e2a MyBatis \u7f13\u5b58\u8e29\u5751\u7684\u573a\u666f\uff1a\u53d6\u6570\u7ebf\u7a0b\u4ece\u6570\u636e\u5e93\u83b7\u53d6\u4e00\u6279\u672a\u5904\u7406\u7684\u4efb\u52a1\uff0c\u7136\u540e\u63d0\u4ea4\u5230\u4e00\u4e2a\u7ebf\u7a0b\u6c60\u8fdb\u884c\u5904\u7406\uff0c\u5904\u7406\u5b8c\u540e\u518d\u53d6\u4e0b\u4e00\u6279\uff0c\u76f4\u81f3\u6240\u6709\u672a\u5904\u7406\u7684\u4efb\u52a1\u5904\u7406\u5b8c\u6210\u3002\u56e0\u4e3a\u53d6\u6570\u7ebf\u7a0b\u6bcf\u6b21\u90fd\u53ea\u8d1f\u8d23\u8bfb\u64cd\u4f5c\u3001\u66f4\u65b0\u64cd\u4f5c\u662f\u7531\u7ebf\u7a0b\u6c60\u91cc\u7684\u7ebf\u7a0b\u6267\u884c\u7684\uff0c\u56e0\u6b64\u53d6\u6570\u7ebf\u7a0b\u5173\u8054\u7684 SqlSession \u7684\u4e00\u7ea7\u7f13\u5b58\u5bf9\u6570\u636e\u8fdb\u884c\u4e86\u7f13\u5b58\uff0c\u5bfc\u81f4\u6570\u636e\u4f1a\u88ab\u91cd\u590d\u5904\u7406\u3002\u4fee\u590d\u4e5f\u7b80\u5355\uff0c\u53d6\u6570\u7ebf\u7a0b\u5728\u4efb\u52a1\u5904\u7406\u5b8c\u6210\u540e\u6e05\u9664\u7f13\u5b58\u6216\u8005\u628a\u53d6\u6570 SQL \u7684\u7f13\u5b58\u7ea7\u522b\u8bbe\u7f6e\u4e3a <code>STATEMENT<\/code>\u3002<\/p>\n<hr \/>\n<p>\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u5fae\u4fe1\u516c\u4f17\u53f7: <strong>coderbee\u7b14\u8bb0<\/strong>\uff0c\u53ef\u4ee5\u66f4\u53ca\u65f6\u56de\u590d\u4f60\u7684\u8ba8\u8bba\u3002<br \/>\n<img loading=\"lazy\" decoding=\"async\" width=\"258\" height=\"258\" src=\"https:\/\/coderbee.net\/wp-content\/uploads\/2019\/01\/coderbee-note.jpg\" class=\"alignnone size-full wp-image-1707\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6240\u6709 insert\/update\/delete \u8bed\u53e5\u90fd\u4f1a\u5bfc\u81f4\u7f13\u5b58\u88ab\u6e05\u9664\u3002 1.  &hellip; <a href=\"https:\/\/coderbee.net\/index.php\/framework\/20191024\/1996\">\u7ee7\u7eed\u9605\u8bfb <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[255],"tags":[228,332],"_links":{"self":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1996"}],"collection":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/comments?post=1996"}],"version-history":[{"count":5,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1996\/revisions"}],"predecessor-version":[{"id":1998,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1996\/revisions\/1998"}],"wp:attachment":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/media?parent=1996"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/categories?post=1996"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/tags?post=1996"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}