我想将 sql:query 替换为一些 Java 代码，这些代码构建具有多个参数的复杂查询。当前的sql是一个简单的select。
<sql:query
var="result"
dataSource="${dSource}"
sql="select * from TABLE ">
</sql:query>
我如何获取我的 Java ResultSet(即 rs = stmt.executeQuery(sql);)并使结果在我的 JSP 中可用，以便我可以执行这本教科书 JSP？
为了更清楚，我想删除上面的查询并将其替换为 Java。
<%
ResultSet rs = stmt.executeQuery(sql); // Messy code will be in some Controller
%>
<c:forEach var="row" items="${result.rows}">
<c:out value="${row.name}"/>
</c:forEach>
我是在 Java 部分设置 session /页面变量，还是有一些 EL 技巧可以用来访问变量？
模型(行):
public class Row {
private String name;
// Add/generate constructor(s), getters and setters.
}
道:
public List<Row> list() throws SQLException {
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
List<Row> rows = new ArrayList<Row>();
try {
connection = database.getConnection();
statement = connection.createStatement();
resultSet = statement.executeQuery(SQL_LIST);
while (resultSet.next()) {
Row row = new Row();
row.setName(resultSet.getString("name"));
// ...
rows.add(row);
}
} finally {
if (resultSet != null) try { resultSet.close(); } catch (SQLException logOrIgnore) {}
if (statement != null) try { statement.close(); } catch (SQLException logOrIgnore) {}
if (connection != null) try { connection.close(); } catch (SQLException logOrIgnore) {}
}
return rows;
}
Controller (servlet):
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
try {
List<Row> rows = someDAO.list();
request.setAttribute("rows", rows);
} catch (SQLException e) {
request.setAttribute("error", "Retrieving rows failed.");
e.printStackTrace();
}
request.getRequestDispatcher("page.jsp").forward(request, response);
}
View (page.jsp):
<c:forEach items="${rows}" var="row">
<c:out value="${row.name}" />
...
</c:forEach>
<c:if test="${not empty error}">Error: ${error}</c:if>