예제 #1
0
 /**
  * 根据数据库方言,生成特定的分页sql
  *
  * @param sql
  * @param page
  * @return
  */
 private String generatePageSql(String sql, Page page) {
   if (page != null && Tools.notEmpty(dialect)) {
     StringBuffer pageSql = new StringBuffer();
     if ("mysql".equals(dialect)) {
       pageSql.append(sql);
       pageSql.append(" limit " + page.getCurrentResult() + "," + page.getShowCount());
     } else if ("oracle".equals(dialect)) {
       pageSql.append("select * from (select tmp_tb.*,ROWNUM row_id from (");
       pageSql.append(sql);
       // pageSql.append(") as tmp_tb where ROWNUM<=");
       pageSql.append(") tmp_tb where ROWNUM<=");
       pageSql.append(page.getCurrentResult() + page.getShowCount());
       pageSql.append(") where row_id>");
       pageSql.append(page.getCurrentResult());
     }
     return pageSql.toString();
   } else {
     return sql;
   }
 }
예제 #2
0
  public Object intercept(Invocation ivk) throws Throwable {
    // TODO Auto-generated method stub
    if (ivk.getTarget() instanceof RoutingStatementHandler) {
      RoutingStatementHandler statementHandler = (RoutingStatementHandler) ivk.getTarget();
      BaseStatementHandler delegate =
          (BaseStatementHandler) ReflectHelper.getValueByFieldName(statementHandler, "delegate");
      MappedStatement mappedStatement =
          (MappedStatement) ReflectHelper.getValueByFieldName(delegate, "mappedStatement");

      if (mappedStatement.getId().matches(pageSqlId)) { // 拦截需要分页的SQL
        BoundSql boundSql = delegate.getBoundSql();
        Object parameterObject =
            boundSql
                .getParameterObject(); // 分页SQL<select>中parameterType属性对应的实体参数,即Mapper接口中执行分页方法的参数,该参数不得为空
        if (parameterObject == null) {
          throw new NullPointerException("parameterObject尚未实例化!");
        } else {
          Connection connection = (Connection) ivk.getArgs()[0];
          String sql = boundSql.getSql();
          // String countSql = "select count(0) from (" + sql+ ") as tmp_count"; //记录统计
          String countSql =
              "select count(0) from ("
                  + sql
                  + ")  tmp_count"; // 记录统计 == oracle 加 as 报错(SQL command not properly ended)
          PreparedStatement countStmt = connection.prepareStatement(countSql);
          BoundSql countBS =
              new BoundSql(
                  mappedStatement.getConfiguration(),
                  countSql,
                  boundSql.getParameterMappings(),
                  parameterObject);
          setParameters(countStmt, mappedStatement, countBS, parameterObject);
          ResultSet rs = countStmt.executeQuery();
          int count = 0;
          if (rs.next()) {
            count = rs.getInt(1);
          }
          rs.close();
          countStmt.close();
          // System.out.println(count);
          Page page = null;
          if (parameterObject instanceof Page) { // 参数就是Page实体
            page = (Page) parameterObject;
            page.setEntityOrField(true);
            page.setTotalResult(count);
          } else { // 参数为某个实体,该实体拥有Page属性
            Field pageField = ReflectHelper.getFieldByFieldName(parameterObject, "page");
            if (pageField != null) {
              page = (Page) ReflectHelper.getValueByFieldName(parameterObject, "page");
              if (page == null) page = new Page();
              page.setEntityOrField(false);
              page.setTotalResult(count);
              ReflectHelper.setValueByFieldName(parameterObject, "page", page); // 通过反射,对实体对象设置分页对象
            } else {
              throw new NoSuchFieldException(parameterObject.getClass().getName() + "不存在 page 属性!");
            }
          }
          String pageSql = generatePageSql(sql, page);
          ReflectHelper.setValueByFieldName(boundSql, "sql", pageSql); // 将分页sql语句反射回BoundSql.
        }
      }
    }
    return ivk.proceed();
  }