数据库路由中间件MyCat - 源代码篇（12） 4.配置模块 4.2 schema.xml 接上一篇，接下来载入每个schema的配置（也就是每个MyCat中虚拟化的数据库的配置）： XMLSchemaLoader.java private void loadSchemas(Element root) { NodeList list = root . getElemen
接上一篇，接下来载入每个schema的配置（也就是每个MyCat中虚拟化的数据库的配置）：
XMLSchemaLoader.java
<code class=" hljs lasso"><span class="hljs-keyword">private</span> <span class="hljs-literal">void</span> loadSchemas(Element root) {
NodeList <span class="hljs-built_in">list</span> <span class="hljs-subst">=</span> root<span class="hljs-built_in">.</span>getElementsByTagName(<span class="hljs-string">"schema"</span>);
for (int i <span class="hljs-subst">=</span> <span class="hljs-number">0</span>, n <span class="hljs-subst">=</span> <span class="hljs-built_in">list</span><span class="hljs-built_in">.</span>getLength(); i <span class="hljs-subst"><</span> n; i<span class="hljs-subst">++</span>) {
Element schemaElement <span class="hljs-subst">=</span> (Element) <span class="hljs-built_in">list</span><span class="hljs-built_in">.</span>item(i);
<span class="hljs-comment">//读取各个属性</span>
<span class="hljs-built_in">String</span> name <span class="hljs-subst">=</span> schemaElement<span class="hljs-built_in">.</span>getAttribute(<span class="hljs-string">"name"</span>);
<span class="hljs-built_in">String</span> dataNode <span class="hljs-subst">=</span> schemaElement<span class="hljs-built_in">.</span>getAttribute(<span class="hljs-string">"dataNode"</span>);
<span class="hljs-built_in">String</span> checkSQLSchemaStr <span class="hljs-subst">=</span> schemaElement<span class="hljs-built_in">.</span>getAttribute(<span class="hljs-string">"checkSQLschema"</span>);
<span class="hljs-built_in">String</span> sqlMaxLimitStr <span class="hljs-subst">=</span> schemaElement<span class="hljs-built_in">.</span>getAttribute(<span class="hljs-string">"sqlMaxLimit"</span>);
int sqlMaxLimit <span class="hljs-subst">=</span> <span class="hljs-subst">-</span><span class="hljs-number">1</span>;
<span class="hljs-comment">//读取sql返回结果集限制</span>
<span class="hljs-keyword">if</span> (sqlMaxLimitStr <span class="hljs-subst">!=</span> <span class="hljs-built_in">null</span> <span class="hljs-subst">&&</span> <span class="hljs-subst">!</span>sqlMaxLimitStr<span class="hljs-built_in">.</span>isEmpty()) {
sqlMaxLimit <span class="hljs-subst">=</span> <span class="hljs-built_in">Integer</span><span class="hljs-built_in">.</span>valueOf(sqlMaxLimitStr);
}
<span class="hljs-comment">// check dataNode already exists or not,看schema标签中是否有datanode</span>
<span class="hljs-built_in">String</span> defaultDbType <span class="hljs-subst">=</span> <span class="hljs-built_in">null</span>;
<span class="hljs-comment">//校验检查并添加dataNode</span>
<span class="hljs-keyword">if</span> (dataNode <span class="hljs-subst">!=</span> <span class="hljs-built_in">null</span> <span class="hljs-subst">&&</span> <span class="hljs-subst">!</span>dataNode<span class="hljs-built_in">.</span>isEmpty()) {
<span class="hljs-built_in">List</span><span class="hljs-subst"><</span><span class="hljs-built_in">String</span><span class="hljs-subst">></span> dataNodeLst <span class="hljs-subst">=</span> <span class="hljs-literal">new</span> ArrayList<span class="hljs-subst"><</span><span class="hljs-built_in">String</span><span class="hljs-subst">></span>(<span class="hljs-number">1</span>);
dataNodeLst<span class="hljs-built_in">.</span>add(dataNode);
checkDataNodeExists(dataNodeLst);
<span class="hljs-built_in">String</span> dataHost <span class="hljs-subst">=</span> dataNodes<span class="hljs-built_in">.</span>get(dataNode)<span class="hljs-built_in">.</span>getDataHost();
defaultDbType <span class="hljs-subst">=</span> dataHosts<span class="hljs-built_in">.</span>get(dataHost)<span class="hljs-built_in">.</span>getDbType();
} <span class="hljs-keyword">else</span> {
dataNode <span class="hljs-subst">=</span> <span class="hljs-built_in">null</span>;
}
<span class="hljs-comment">//加载schema下所有tables</span>
<span class="hljs-built_in">Map</span><span class="hljs-subst"><</span><span class="hljs-built_in">String</span>, TableConfig<span class="hljs-subst">></span> tables <span class="hljs-subst">=</span> loadTables(schemaElement);
<span class="hljs-comment">//判断schema是否重复</span>
<span class="hljs-keyword">if</span> (schemas<span class="hljs-built_in">.</span>containsKey(name)) {
throw <span class="hljs-literal">new</span> ConfigException(<span class="hljs-string">"schema "</span> <span class="hljs-subst">+</span> name <span class="hljs-subst">+</span> <span class="hljs-string">" duplicated!"</span>);
}
<span class="hljs-comment">// 设置了table的不需要设置dataNode属性，没有设置table的必须设置dataNode属性</span>
<span class="hljs-keyword">if</span> (dataNode <span class="hljs-subst">==</span> <span class="hljs-built_in">null</span> <span class="hljs-subst">&&</span> tables<span class="hljs-built_in">.</span>size() <span class="hljs-subst">==</span> <span class="hljs-number">0</span>) {
throw <span class="hljs-literal">new</span> ConfigException(
<span class="hljs-string">"schema "</span> <span class="hljs-subst">+</span> name <span class="hljs-subst">+</span> <span class="hljs-string">" didn't config tables,so you must set dataNode property!"</span>);
}
SchemaConfig schemaConfig <span class="hljs-subst">=</span> <span class="hljs-literal">new</span> SchemaConfig(name, dataNode,
tables, sqlMaxLimit, <span class="hljs-string">"true"</span><span class="hljs-built_in">.</span>equalsIgnoreCase(checkSQLSchemaStr));
<span class="hljs-comment">//设定DB类型，这对之后的sql语句路由解析有帮助</span>
<span class="hljs-keyword">if</span> (defaultDbType <span class="hljs-subst">!=</span> <span class="hljs-built_in">null</span>) {
schemaConfig<span class="hljs-built_in">.</span>setDefaultDataNodeDbType(defaultDbType);
<span class="hljs-keyword">if</span> (<span class="hljs-subst">!</span><span class="hljs-string">"mysql"</span><span class="hljs-built_in">.</span>equalsIgnoreCase(defaultDbType)) {
schemaConfig<span class="hljs-built_in">.</span>setNeedSupportMultiDBType(<span class="hljs-literal">true</span>);
}
}
<span class="hljs-comment">// 判断是否有不是mysql的数据库类型，方便解析判断是否启用多数据库分页语法解析</span>
for (<span class="hljs-built_in">String</span> tableName : tables<span class="hljs-built_in">.</span>keySet()) {
TableConfig tableConfig <span class="hljs-subst">=</span> tables<span class="hljs-built_in">.</span>get(tableName);
<span class="hljs-keyword">if</span> (isHasMultiDbType(tableConfig)) {
schemaConfig<span class="hljs-built_in">.</span>setNeedSupportMultiDBType(<span class="hljs-literal">true</span>);
break;
}
}
<span class="hljs-comment">//记录每种dataNode的DB类型</span>
<span class="hljs-built_in">Map</span><span class="hljs-subst"><</span><span class="hljs-built_in">String</span>, <span class="hljs-built_in">String</span><span class="hljs-subst">></span> dataNodeDbTypeMap <span class="hljs-subst">=</span> <span class="hljs-literal">new</span> HashMap<span class="hljs-subst"><></span>();
for (<span class="hljs-built_in">String</span> dataNodeName : dataNodes<span class="hljs-built_in">.</span>keySet()) {
DataNodeConfig dataNodeConfig <span class="hljs-subst">=</span> dataNodes<span class="hljs-built_in">.</span>get(dataNodeName);
<span class="hljs-built_in">String</span> dataHost <span class="hljs-subst">=</span> dataNodeConfig<span class="hljs-built_in">.</span>getDataHost();
DataHostConfig dataHostConfig <span class="hljs-subst">=</span> dataHosts<span class="hljs-built_in">.</span>get(dataHost);
<span class="hljs-keyword">if</span> (dataHostConfig <span class="hljs-subst">!=</span> <span class="hljs-built_in">null</span>) {
<span class="hljs-built_in">String</span> dbType <span class="hljs-subst">=</span> dataHostConfig<span class="hljs-built_in">.</span>getDbType();
dataNodeDbTypeMap<span class="hljs-built_in">.</span>put(dataNodeName, dbType);
}
}
schemaConfig<span class="hljs-built_in">.</span>setDataNodeDbTypeMap(dataNodeDbTypeMap);
schemas<span class="hljs-built_in">.</span>put(name, schemaConfig);
}
}</code>首先读取schema每个配置属性项，并作有效性判断。比如默认的dataNode是否存在。只要验证之前读取的dataNode里面有没有就可以
<code class=" hljs cs"><span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">checkDataNodeExists</span>(Collection<String> nodes) {
<span class="hljs-keyword">if</span> (nodes == <span class="hljs-keyword">null</span> || nodes.size() < <span class="hljs-number">1</span>) {
<span class="hljs-keyword">return</span>;
}
<span class="hljs-keyword">for</span> (String node : nodes) {
<span class="hljs-keyword">if</span> (!dataNodes.containsKey(node)) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(<span class="hljs-string">"dataNode '"</span> + node + <span class="hljs-string">"' is not found!"</span>);
}
}
}</code>之后载入所有的table和childTable：
<code class=" hljs javascript">private Map<<span class="hljs-built_in">String</span>, TableConfig> loadTables(Element node) {
<span class="hljs-comment">// Map<String, TableConfig> tables = new HashMap<String, TableConfig>();</span>
<span class="hljs-comment">// 支持表名中包含引号[`] BEN GONG</span>
Map<<span class="hljs-built_in">String</span>, TableConfig> tables = <span class="hljs-keyword">new</span> TableConfigMap();
NodeList nodeList = node.getElementsByTagName(<span class="hljs-string">"table"</span>);
<span class="hljs-keyword">for</span> (int i = <span class="hljs-number">0</span>; i < nodeList.getLength(); i++) {
Element tableElement = (Element) nodeList.item(i);
<span class="hljs-built_in">String</span> tableNameElement = tableElement.getAttribute(<span class="hljs-string">"name"</span>).toUpperCase();
<span class="hljs-comment">//TODO:路由, 增加对动态日期表的支持</span>
<span class="hljs-built_in">String</span> tableNameSuffixElement = tableElement.getAttribute(<span class="hljs-string">"nameSuffix"</span>).toUpperCase();
<span class="hljs-keyword">if</span> ( !<span class="hljs-string">""</span>.equals( tableNameSuffixElement ) ) {
<span class="hljs-keyword">if</span>( tableNameElement.split(<span class="hljs-string">","</span>).length > <span class="hljs-number">1</span> ) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(<span class="hljs-string">"nameSuffix "</span> + tableNameSuffixElement + <span class="hljs-string">", require name parameter cannot multiple breaks!"</span>);
}
<span class="hljs-comment">//前缀用来标明日期格式</span>
tableNameElement = doTableNameSuffix(tableNameElement, tableNameSuffixElement);
}
<span class="hljs-comment">//记录主键，用于之后路由分析，以及启用自增长主键</span>
<span class="hljs-built_in">String</span>[] tableNames = tableNameElement.split(<span class="hljs-string">","</span>);
<span class="hljs-built_in">String</span> primaryKey = tableElement.hasAttribute(<span class="hljs-string">"primaryKey"</span>) ? tableElement.getAttribute(<span class="hljs-string">"primaryKey"</span>).toUpperCase() : <span class="hljs-literal">null</span>;
<span class="hljs-comment">//记录是否主键自增，默认不是，（启用全局sequence handler）</span>
boolean autoIncrement = <span class="hljs-literal">false</span>;
<span class="hljs-keyword">if</span> (tableElement.hasAttribute(<span class="hljs-string">"autoIncrement"</span>)) {
autoIncrement = <span class="hljs-built_in">Boolean</span>.parseBoolean(tableElement.getAttribute(<span class="hljs-string">"autoIncrement"</span>));
}
<span class="hljs-comment">//记录是否需要加返回结果集限制，默认需要加</span>
boolean needAddLimit = <span class="hljs-literal">true</span>;
<span class="hljs-keyword">if</span> (tableElement.hasAttribute(<span class="hljs-string">"needAddLimit"</span>)) {
needAddLimit = <span class="hljs-built_in">Boolean</span>.parseBoolean(tableElement.getAttribute(<span class="hljs-string">"needAddLimit"</span>));
}
<span class="hljs-comment">//记录type，是否为global</span>
<span class="hljs-built_in">String</span> tableTypeStr = tableElement.hasAttribute(<span class="hljs-string">"type"</span>) ? tableElement.getAttribute(<span class="hljs-string">"type"</span>) : <span class="hljs-literal">null</span>;
int tableType = TableConfig.TYPE_GLOBAL_DEFAULT;
<span class="hljs-keyword">if</span> (<span class="hljs-string">"global"</span>.equalsIgnoreCase(tableTypeStr)) {
tableType = TableConfig.TYPE_GLOBAL_TABLE;
}
<span class="hljs-comment">//记录dataNode，就是分布在哪些dataNode上</span>
<span class="hljs-built_in">String</span> dataNode = tableElement.getAttribute(<span class="hljs-string">"dataNode"</span>);
TableRuleConfig tableRule = <span class="hljs-literal">null</span>;
<span class="hljs-keyword">if</span> (tableElement.hasAttribute(<span class="hljs-string">"rule"</span>)) {
<span class="hljs-built_in">String</span> ruleName = tableElement.getAttribute(<span class="hljs-string">"rule"</span>);
tableRule = tableRules.get(ruleName);
<span class="hljs-keyword">if</span> (tableRule == <span class="hljs-literal">null</span>) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(<span class="hljs-string">"rule "</span> + ruleName + <span class="hljs-string">" is not found!"</span>);
}
}
boolean ruleRequired = <span class="hljs-literal">false</span>;
<span class="hljs-comment">//记录是否绑定有分片规则</span>
<span class="hljs-keyword">if</span> (tableElement.hasAttribute(<span class="hljs-string">"ruleRequired"</span>)) {
ruleRequired = <span class="hljs-built_in">Boolean</span>.parseBoolean(tableElement.getAttribute(<span class="hljs-string">"ruleRequired"</span>));
}
<span class="hljs-keyword">if</span> (tableNames == <span class="hljs-literal">null</span>) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(<span class="hljs-string">"table name is not found!"</span>);
}
<span class="hljs-comment">//distribute函数，重新编排dataNode</span>
<span class="hljs-built_in">String</span> distPrex = <span class="hljs-string">"distribute("</span>;
boolean distTableDns = dataNode.startsWith(distPrex);
<span class="hljs-keyword">if</span> (distTableDns) {
dataNode = dataNode.substring(distPrex.length(), dataNode.length() - <span class="hljs-number">1</span>);
}
<span class="hljs-comment">//分表功能</span>
<span class="hljs-built_in">String</span> subTables = tableElement.getAttribute(<span class="hljs-string">"subTables"</span>);
<span class="hljs-keyword">for</span> (int j = <span class="hljs-number">0</span>; j < tableNames.length; j++) {
<span class="hljs-built_in">String</span> tableName = tableNames[j];
TableConfig table = <span class="hljs-keyword">new</span> TableConfig(tableName, primaryKey,
autoIncrement, needAddLimit, tableType, dataNode,
getDbType(dataNode),
(tableRule != <span class="hljs-literal">null</span>) ? tableRule.getRule() : <span class="hljs-literal">null</span>,
ruleRequired, <span class="hljs-literal">null</span>, <span class="hljs-literal">false</span>, <span class="hljs-literal">null</span>, <span class="hljs-literal">null</span>,subTables);
checkDataNodeExists(table.getDataNodes());
<span class="hljs-keyword">if</span> (distTableDns) {
distributeDataNodes(table.getDataNodes());
}
<span class="hljs-comment">//检查去重</span>
<span class="hljs-keyword">if</span> (tables.containsKey(table.getName())) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(<span class="hljs-string">"table "</span> + tableName + <span class="hljs-string">" duplicated!"</span>);
}
<span class="hljs-comment">//放入map</span>
tables.put(table.getName(), table);
}
<span class="hljs-comment">//只有tableName配置的是单个表（没有逗号）的时候才能有子表</span>
<span class="hljs-keyword">if</span> (tableNames.length == <span class="hljs-number">1</span>) {
TableConfig table = tables.get(tableNames[<span class="hljs-number">0</span>]);
<span class="hljs-comment">// process child tables</span>
processChildTables(tables, table, dataNode, tableElement);
}
}
<span class="hljs-keyword">return</span> tables;
}</code>对于子表，有递归读取配置：
<code class=" hljs javascript">private <span class="hljs-keyword">void</span> processChildTables(Map<<span class="hljs-built_in">String</span>, TableConfig> tables,
TableConfig parentTable, <span class="hljs-built_in">String</span> dataNodes, Element tableNode) {
<span class="hljs-comment">// parse child tables</span>
NodeList childNodeList = tableNode.getChildNodes();
<span class="hljs-keyword">for</span> (int j = <span class="hljs-number">0</span>; j < childNodeList.getLength(); j++) {
Node theNode = childNodeList.item(j);
<span class="hljs-keyword">if</span> (!theNode.getNodeName().equals(<span class="hljs-string">"childTable"</span>)) {
<span class="hljs-keyword">continue</span>;
}
Element childTbElement = (Element) theNode;
<span class="hljs-comment">//读取子表信息</span>
<span class="hljs-built_in">String</span> cdTbName = childTbElement.getAttribute(<span class="hljs-string">"name"</span>).toUpperCase();
<span class="hljs-built_in">String</span> primaryKey = childTbElement.hasAttribute(<span class="hljs-string">"primaryKey"</span>) ? childTbElement.getAttribute(<span class="hljs-string">"primaryKey"</span>).toUpperCase() : <span class="hljs-literal">null</span>;
boolean autoIncrement = <span class="hljs-literal">false</span>;
<span class="hljs-keyword">if</span> (childTbElement.hasAttribute(<span class="hljs-string">"autoIncrement"</span>)) {
autoIncrement = <span class="hljs-built_in">Boolean</span>.parseBoolean(childTbElement.getAttribute(<span class="hljs-string">"autoIncrement"</span>));
}
boolean needAddLimit = <span class="hljs-literal">true</span>;
<span class="hljs-keyword">if</span> (childTbElement.hasAttribute(<span class="hljs-string">"needAddLimit"</span>)) {
needAddLimit = <span class="hljs-built_in">Boolean</span>.parseBoolean(childTbElement.getAttribute(<span class="hljs-string">"needAddLimit"</span>));
}
<span class="hljs-built_in">String</span> subTables = childTbElement.getAttribute(<span class="hljs-string">"subTables"</span>);
<span class="hljs-comment">//子表join键，和对应的parent的键，父子表通过这个关联</span>
<span class="hljs-built_in">String</span> joinKey = childTbElement.getAttribute(<span class="hljs-string">"joinKey"</span>).toUpperCase();
<span class="hljs-built_in">String</span> parentKey = childTbElement.getAttribute(<span class="hljs-string">"parentKey"</span>).toUpperCase();
TableConfig table = <span class="hljs-keyword">new</span> TableConfig(cdTbName, primaryKey,
autoIncrement, needAddLimit,
TableConfig.TYPE_GLOBAL_DEFAULT, dataNodes,
getDbType(dataNodes), <span class="hljs-literal">null</span>, <span class="hljs-literal">false</span>, parentTable, <span class="hljs-literal">true</span>,
joinKey, parentKey, subTables);
<span class="hljs-keyword">if</span> (tables.containsKey(table.getName())) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(<span class="hljs-string">"table "</span> + table.getName() + <span class="hljs-string">" duplicated!"</span>);
}
tables.put(table.getName(), table);
<span class="hljs-comment">//对于子表的子表，递归处理</span>
processChildTables(tables, table, dataNodes, childTbElement);
}
}</code>对于表的dataNode对应关系，有个特殊配置即类似dataNode=”distributed(dn$1-10)”，这个含义是：
<code class="language-java hljs "><span class="hljs-javadoc">/**
* distribute datanodes in multi hosts,means ,dn1 (host1),dn100
* (host2),dn300(host3),dn2(host1),dn101(host2),dn301(host3)...etc
* 将每个host上的datanode按照host重新排列。比如上面的例子host1拥有dn1,dn2，host2拥有dn100，dn101，host3拥有dn300，dn301,
* 按照host重新排列： 0->dn1 (host1),1->dn100(host2),2->dn300(host3),3->dn2(host1),4->dn101(host2),5->dn301(host3)
*
*<span class="hljs-javadoctag"> @param</span> theDataNodes
*/</span>
<span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">distributeDataNodes</span>(ArrayList<String> theDataNodes) {
Map<String, ArrayList<String>> newDataNodeMap = <span class="hljs-keyword">new</span> HashMap<String, ArrayList<String>>(dataHosts.size());
<span class="hljs-keyword">for</span> (String dn : theDataNodes) {
DataNodeConfig dnConf = dataNodes.get(dn);
String host = dnConf.getDataHost();
ArrayList<String> hostDns = newDataNodeMap.get(host);
hostDns = (hostDns == <span class="hljs-keyword">null</span>) ? <span class="hljs-keyword">new</span> ArrayList<String>() : hostDns;
hostDns.add(dn);
newDataNodeMap.put(host, hostDns);
}
ArrayList<String> result = <span class="hljs-keyword">new</span> ArrayList<String>(theDataNodes.size());
<span class="hljs-keyword">boolean</span> hasData = <span class="hljs-keyword">true</span>;
<span class="hljs-keyword">while</span> (hasData) {
hasData = <span class="hljs-keyword">false</span>;
<span class="hljs-keyword">for</span> (ArrayList<String> dns : newDataNodeMap.values()) {
<span class="hljs-keyword">if</span> (!dns.isEmpty()) {
result.add(dns.remove(<span class="hljs-number">0</span>));
hasData = <span class="hljs-keyword">true</span>;
}
}
}
theDataNodes.clear();
theDataNodes.addAll(result);
}</code>读取完所有表之后，记录好DB类型，这对之后的sql语句路由解析有帮助。将所有schema的配置保存在：
<code class=" hljs java"><span class="hljs-keyword">private</span> <span class="hljs-keyword">final</span> Map<String, SchemaConfig> schemas;</code>
之后会读取载入server配置。
XMLConfigLoader.java:
<code class=" hljs avrasm">public XMLConfigLoader(SchemaLoader schemaLoader) {
XMLServerLoader serverLoader = new XMLServerLoader()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.system</span> = serverLoader<span class="hljs-preprocessor">.getSystem</span>()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.users</span> = serverLoader<span class="hljs-preprocessor">.getUsers</span>()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.quarantine</span> = serverLoader<span class="hljs-preprocessor">.getQuarantine</span>()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.cluster</span> = serverLoader<span class="hljs-preprocessor">.getCluster</span>()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.dataHosts</span> = schemaLoader<span class="hljs-preprocessor">.getDataHosts</span>()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.dataNodes</span> = schemaLoader<span class="hljs-preprocessor">.getDataNodes</span>()<span class="hljs-comment">;</span>
this<span class="hljs-preprocessor">.schemas</span> = schemaLoader<span class="hljs-preprocessor">.getSchemas</span>()<span class="hljs-comment">;</span>
schemaLoader = null<span class="hljs-comment">;</span>
}</code>XMLServerLoader.java
<code class=" hljs cs"><span class="hljs-keyword">public</span> <span class="hljs-title">XMLServerLoader</span>() {
<span class="hljs-keyword">this</span>.system = <span class="hljs-keyword">new</span> SystemConfig();
<span class="hljs-keyword">this</span>.users = <span class="hljs-keyword">new</span> HashMap<String, UserConfig>();
<span class="hljs-keyword">this</span>.quarantine = <span class="hljs-keyword">new</span> QuarantineConfig();
<span class="hljs-keyword">this</span>.load();
}
<span class="hljs-keyword">private</span> <span class="hljs-keyword">void</span> <span class="hljs-title">load</span>() {
<span class="hljs-comment">//读取server.xml配置</span>
InputStream dtd = <span class="hljs-keyword">null</span>;
InputStream xml = <span class="hljs-keyword">null</span>;
<span class="hljs-keyword">try</span> {
dtd = XMLServerLoader.class.getResourceAsStream(<span class="hljs-string">"/server.dtd"</span>);
xml = XMLServerLoader.class.getResourceAsStream(<span class="hljs-string">"/server.xml"</span>);
Element root = ConfigUtil.getDocument(dtd, xml).getDocumentElement();
<span class="hljs-comment">//加载System标签</span>
loadSystem(root);
<span class="hljs-comment">//加载User标签</span>
loadUsers(root);
<span class="hljs-comment">//加载集群配置</span>
<span class="hljs-keyword">this</span>.cluster = <span class="hljs-keyword">new</span> ClusterConfig(root, system.getServerPort());
<span class="hljs-comment">//加载权限和黑白名单</span>
loadQuarantine(root);
} <span class="hljs-keyword">catch</span> (ConfigException e) {
<span class="hljs-keyword">throw</span> e;
} <span class="hljs-keyword">catch</span> (Exception e) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> ConfigException(e);
} <span class="hljs-keyword">finally</span> {
<span class="hljs-keyword">if</span> (dtd != <span class="hljs-keyword">null</span>) {
<span class="hljs-keyword">try</span> {
dtd.close();
} <span class="hljs-keyword">catch</span> (IOException e) {
}
}
<span class="hljs-keyword">if</span> (xml != <span class="hljs-keyword">null</span>) {
<span class="hljs-keyword">try</span> {
xml.close();
} <span class="hljs-keyword">catch</span> (IOException e) {
}
}
}
}</code>首先加载System标签
Datenbank drei Paradigmen
So löschen Sie eine Datenbank
So stellen Sie eine Verbindung zur Datenbank in VB her
MySQL-Datenbank wiederherstellen
So stellen Sie eine Verbindung zum Zugriff auf die Datenbank in VB her
So lösen Sie das Problem eines ungültigen Datenbankobjektnamens
So verbinden Sie VB mit dem Zugriff auf die Datenbank
So stellen Sie mit vb eine Verbindung zur Datenbank her
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