fixed nutzam#1116 nutzam#1117

Signed-off-by: wendal chen <wendal1985@gmail.com>

src/org/nutz/dao/DaoInterceptor.java

@@ -0,0 +1,12 @@
+package org.nutz.dao;
+
+/**
+ * Dao操作拦截器
+ * @author wendal
+ * @see org.nutz.dao.impl.interceptor.DaoLogInterceptor
+ * @see org.nutz.dao.impl.interceptor.DaoTimeInterceptor
+ */
+public interface DaoInterceptor {
+
+    void filter(DaoInterceptorChain chain) throws DaoException;
+}

src/org/nutz/dao/DaoInterceptorChain.java

@@ -0,0 +1,226 @@
+package org.nutz.dao;
+
+import java.sql.Connection;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.nutz.dao.impl.DaoExecutor;
+import org.nutz.dao.sql.DaoStatement;
+import org.nutz.dao.sql.SqlContext;
+import org.nutz.lang.random.R;
+import org.nutz.log.Log;
+import org.nutz.log.Logs;
+
+/**
+ * Dao执行拦截器链.
+ * 
+ * @author wendal
+ * @see org.nutz.dao.impl.interceptor.DaoLogInterceptor
+ * @see org.nutz.dao.impl.interceptor.DaoTimeInterceptor
+ */
+public class DaoInterceptorChain implements ConnCallback {
+
+    private static final Log log = Logs.get();
+
+    protected int autoTransLevel;
+
+    protected Connection connection;
+
+    protected int current = 0;
+
+    protected DaoStatement daoStatement;
+
+    protected DaoExecutor executor;
+
+    protected List<DaoInterceptor> interceptors = new ArrayList<DaoInterceptor>();
+
+    protected int updateCount;
+
+    protected DaoStatement[] sts;
+
+    protected String id;
+
+    /**
+     * 新建一个DaoInterceptorChain.
+     * 
+     * @param sts
+     *            将要进行的Dao操作(不一定是SQL操作,有可能是EL)
+     */
+    public DaoInterceptorChain(DaoStatement... sts) {
+        this.sts = sts;
+        id = R.UU32();
+    }
+
+    /**
+     * 继续下一个拦截器,如果已经是最后一个拦截器,那么执行executor.exec
+     * 
+     * @return 本对象,用于链式操作
+     * @throws Exception
+     */
+    public DaoInterceptorChain doChain() throws DaoException {
+        if (hasNext()) {
+            DaoInterceptor interceptor = next();
+            current++;
+            interceptor.filter(this);
+        } else {
+            executor.exec(getConnection(), getDaoStatement());
+            updateCount += getDaoStatement().getUpdateCount();
+        }
+        return this;
+    }
+
+    /**
+     * 获取当前自动事务级别,DaoRunner中使用强制事务时会使用之.拦截器不能修改,即使修改也不会生效
+     * 
+     * @return 当前自动(强制)事务级别
+     */
+    public int getAutoTransLevel() {
+        return autoTransLevel;
+    }
+
+    /**
+     * 当前执行的DaoStatement
+     * 
+     * @return 当前执行的DaoStatement
+     */
+    public DaoStatement getDaoStatement() {
+        return daoStatement;
+    }
+
+    /**
+     * 全部DaoStatement,可能不止一条
+     * 
+     * @return 全部DaoStatement
+     */
+    public DaoStatement[] getDaoStatements() {
+        return sts;
+    }
+
+    /**
+     * 拦截器列表(暂不开放修改)
+     * 
+     * @return 全体拦截器列表
+     */
+    public List<DaoInterceptor> getInterceptors() {
+        return interceptors;
+    }
+
+    /**
+     * 更新总数,用于DaoSupport(NutDao)获取更新总数.
+     * 
+     * @return 更新记录总数
+     */
+    public int getUpdateCount() {
+        return updateCount;
+    }
+
+    /**
+     * 是否还有下一个拦截器
+     * 
+     * @return true,如果还有拦截器要执行
+     */
+    public boolean hasNext() {
+        return current < interceptors.size();
+    }
+
+    /**
+     * 这是DaoExecutor会执行的方法,拦截器内不要执行这个方法!! 这里也是拦截器开始生效的地方.
+     */
+    public void invoke(Connection conn) throws Exception {
+        for (DaoStatement st : sts) {
+            if (st == null) {
+                if (log.isInfoEnabled())
+                    log.info("Found a null DaoStatement(SQL), ingore it ~~");
+                continue;
+            }
+            daoStatement = st;
+            this.connection = conn;
+            doChain();
+        }
+    }
+
+    /**
+     * 获取下一个拦截器. 调用前必须先调用hasNext进行判断
+     * 
+     * @return 下一个拦截器
+     */
+    public DaoInterceptor next() {
+        return interceptors.get(current);
+    }
+
+    /**
+     * 设置强制事务的级别,对拦截器来说无意义.
+     * 
+     * @param autoTransLevel
+     *            与DaoSupport(NutDao)内的值一致
+     */
+    public void setAutoTransLevel(int autoTransLevel) {
+        this.autoTransLevel = autoTransLevel;
+    }
+
+    /**
+     * 设置当前拦截器索引. 若设置值大于拦截器列表的大小,那么效果就等同于跳过剩余拦截器,直接执行DaoStatement
+     * 
+     * @param current
+     */
+    public void setCurrent(int current) {
+        this.current = current;
+    }
+
+    /**
+     * 设置DaoExecutor. 典型应用是在拦截器中替换成daocache提供的DaoExecutor
+     * 
+     * @param executor
+     *            新的DaoExecutor,不可以是null
+     */
+    public void setExecutor(DaoExecutor executor) {
+        this.executor = executor;
+    }
+
+    /**
+     * 设置新的拦截器列表.
+     * 
+     * @param interceptors
+     *            新的拦截器列表
+     */
+    public void setInterceptors(List<DaoInterceptor> interceptors) {
+        this.interceptors = interceptors;
+    }
+
+    /**
+     * 设置当前使用的数据库连接
+     * 
+     * @param connection
+     *            新的数据库连接,不可以是null
+     */
+    public void setConnection(Connection connection) {
+        this.connection = connection;
+    }
+
+    /**
+     * 获取当前数据库连接
+     * 
+     * @return 当前数据库连接
+     */
+    public Connection getConnection() {
+        return connection;
+    }
+
+    /**
+     * 获取当前DaoStatement的上下文,注意,一个拦截器链可能包含多个DaoStatement
+     * 
+     * @return 当前DaoStatement的上下文
+     */
+    public SqlContext getSqlContext() {
+        return getDaoStatement().getContext();
+    }
+
+    /**
+     * 拦截器链的id, 为一个uu32识别符.
+     * 
+     * @return 本拦截器链的id
+     */
+    public String getId() {
+        return id;
+    }
+}