PS:cnxieyang@163.com/xieyang@e6yun.com
本文就Jfinal-plugin的源码进行分析和解读
- Plugin继承及实现关系类图如下，常用的是Iplugin的三个集成类：DruidPlugin、RedisPlugin、ActiveRecordPlugin,下文就父类及3个实现类做解读
- IPlugin详解
IPlugin为Jfinal插件实现类的接口，提供了两个抽象的方法：boolean start(); boolean stop();供子类实现，Jfinal在加载时，调用实现类的start()方法启动插件，所谓插件是将某个业务模块进行了封装，如redis、dbcp等。定义方法如下boolean start();boolean stop(); - IDataSourceProvider详解
IDataSourceProvider提供获取DataSource的方法，其本身为接口，凡是与数据库相关的插件都可以实现IDataSourceProvider接口，接口中的方法如下图DataSource getDataSource();
- 如何加载自定义插件
1.在JFinalConfig实现类的configPlugin(Plugins me)方法中创建对象，将启动逻辑写到插件继承类的start方法中
2.在JFinal的init-->Config.configJFinal(jfinalConfig)-->startPlugins()中完成对插件的start方法的调用，加载插件成功 - RedisPlugin源码解读（不深入到redis，仅读取到Jredis对象的获取，其余部分在后续的redis章节讲解）
PS:此处基本上没有难度，自行研究即可
包括：主缓存、redis缓存的缓存、缓存方法的封装 - DruidPlugin源码解读(仅读取到数据库连接的获取，其余部分在后续得Druid高级使用模块讲解)
DruidPlugin主要是多Druid的DruidDataSource注入了相关的参数变量，不做分析 - ActiveRecordPlugin源码
ActiveRecordPlugin是Jfinal引入的持久层的新思路，下文重点讲解什么是ActiveRecordPlugin、用途、高级使用等
ActiveRecordPlugin实现的是DB+ActiveRecord模式/*** 配置插件*/public void configPlugin(Plugins me) {// 配置C3p0数据库连接池插件DruidPlugin druidPlugin = createDruidPlugin();me.add(druidPlugin);// 配置ActiveRecord插件，需要传入IDataSourceProvider dataSourceProvider，druidPlugin刚刚好是IDataSourceProvider的子类
//A1:初始化ActiveRecordPluginActiveRecordPlugin arp = new ActiveRecordPlugin(druidPlugin);
//A2:所有映射在中自动化搞定，加载映射关系
arp.addMapping("blog", "id", Blog.class);
me.add(arp);
} -
ActiveRecordPlugin如何初始化
1.调用下方构造public ActiveRecordPlugin(IDataSourceProvider dataSourceProvider) {this(DbKit.MAIN_CONFIG_NAME, dataSourceProvider);}
2.继续调用ActiveRecordPlugin(String configName, IDataSourceProvider dataSourceProvider)构造，如下
public ActiveRecordPlugin(String configName, IDataSourceProvider dataSourceProvider) {this(configName, dataSourceProvider, DbKit.DEFAULT_TRANSACTION_LEVEL);}
3.传入事务的级别后再调用构造，如下
public ActiveRecordPlugin(String configName, IDataSourceProvider dataSourceProvider, int transactionLevel) {if (StrKit.isBlank(configName)) {throw new IllegalArgumentException("configName can not be blank");}if (dataSourceProvider == null) {throw new IllegalArgumentException("dataSourceProvider can not be null");}
//IDataSourceProvider 的对象赋值this.dataSourceProvider = dataSourceProvider;
//赋值当前对象的config属性的属性值，PS代码省略
this.config = new Config(configName, null, transactionLevel);
} - 模型与表明如何映射
JFinal为我们提供重载的两个方法，实现对数据表与实体模型的映射，如下放所示//带有主键，主键以逗号隔开
public ActiveRecordPlugin addMapping(String tableName, String primaryKey, Class<? extends Model<?>> modelClass) {tableList.add(new Table(tableName, primaryKey, modelClass));return this;}//不带主键public ActiveRecordPlugin addMapping(String tableName, Class<? extends Model<?>> modelClass) {tableList.add(new Table(tableName, modelClass));return this;}1.有主键的Table的初始化
public Table(String name, String primaryKey, Class<? extends Model<?>> modelClass) {if (StrKit.isBlank(name))throw new IllegalArgumentException("Table name can not be blank.");if (StrKit.isBlank(primaryKey))throw new IllegalArgumentException("Primary key can not be blank.");if (modelClass == null)throw new IllegalArgumentException("Model class can not be null.");this.name = name.trim();setPrimaryKey(primaryKey.trim());this.modelClass = modelClass;}
//将以逗号隔开的主键拆分数数组并赋值给primaryKey对象
void setPrimaryKey(String primaryKey) { String[] arr = primaryKey.split(","); for (int i=0; i<arr.length; i++) arr[i] = arr[i].trim(); this.primaryKey = arr; }2.无主键的Table的初始化
public Table(String name, Class<? extends Model<?>> modelClass) {if (StrKit.isBlank(name))throw new IllegalArgumentException("Table name can not be blank.");if (modelClass == null)throw new IllegalArgumentException("Model class can not be null.");this.name = name.trim();this.modelClass = modelClass;}
3.存储Table关系到List中
ps:ActiveRecordPlugin类中提供了私有集合private List<Table> tableList = new ArrayList<Table>();用来存储table映射到List中 - ActiveRecordPlugin加载并初始化映射关系
PS:插件的启动在JFinal启动源码解读博客章节做了详细介绍<http://www.cnblogs.com/cnxieyang/p/7236734.html>请点击参照。
循坏调用所有插件的Start方法，完成插件的启动，ActiveRecordPlugin的start启动方法如下，下方对所有实现做详细介绍public boolean start() {if (isStarted) {return true;}if (config.dataSource == null && dataSourceProvider != null) {config.dataSource = dataSourceProvider.getDataSource();}if (config.dataSource == null) {throw new RuntimeException("ActiveRecord start error: ActiveRecordPlugin need DataSource or DataSourceProvider");}config.sqlKit.parseSqlTemplate();//C1:构建映射new TableBuilder().build(tableList, config);
//添加配置DbKit.addConfig(config);isStarted = true;return true;}1.C1:构建映射调用build方法
void build(List<Table> tableList, Config config) {// 支持 useAsDataTransfer(...) 中的 arp.start() 正常运作if (config.dataSource instanceof NullDataSource) {return ;}Table temp = null;Connection conn = null;try {conn = config.dataSource.getConnection();TableMapping tableMapping = TableMapping.me();for (Table table : tableList) {temp = table;
//C11：构建doBuild(table, conn, config);
//Map集合中存储映射关系tableMapping.putTable(table);DbKit.addModelToConfigMapping(table.getModelClass(), config);}} catch (Exception e) {if (temp != null) {System.err.println("Can not create Table object, maybe the table " + temp.getName() + " is not exists.");}throw new ActiveRecordException(e);}finally {config.close(conn);}}C11：实现如下
@SuppressWarnings("unchecked")private void doBuild(Table table, Connection conn, Config config) throws SQLException {table.setColumnTypeMap(config.containerFactory.getAttrsMap());if (table.getPrimaryKey() == null) {table.setPrimaryKey(config.dialect.getDefaultPrimaryKey());}//构建查询数据库字段的sqlString sql = config.dialect.forTableBuilderDoBuild(table.getName());Statement stm = conn.createStatement();ResultSet rs = stm.executeQuery(sql);ResultSetMetaData rsmd = rs.getMetaData();//遍历数据表字段，将数据表字段类型映射成JAVA类型，并存储到Table对象中for (int i=1; i<=rsmd.getColumnCount(); i++) {String colName = rsmd.getColumnName(i);String colClassName = rsmd.getColumnClassName(i);Class<?> clazz = javaType.getType(colClassName);if (clazz != null) {table.setColumnType(colName, clazz);}else {int type = rsmd.getColumnType(i);if (type == Types.BINARY || type == Types.VARBINARY || type == Types.BLOB) {table.setColumnType(colName, byte[].class);}else if (type == Types.CLOB || type == Types.NCLOB) {table.setColumnType(colName, String.class);}else {table.setColumnType(colName, String.class);}// core.TypeConverter// throw new RuntimeException("You've got new type to mapping. Please add code in " + TableBuilder.class.getName() + ". The ColumnClassName can't be mapped: " + colClassName); }}rs.close();stm.close();}
备注：以上完成了ActiveRecordPlugin的初始化，后续详解如何使用Db+ActiveRecord的方式加载或者写入数据
PS:时间不早了，休息了。。。