Question

我必须在jsp中从数据库中创建一个饼图。我的数据库由字符串值组成如何执行此操作，请任何人答复下面是我的代码。但它只接受整数值，我必须使用字符串值

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<%@ page import="java.util.*,java.sql.*" %>
<%@ page import="com.google.gson.Gson"%>
<%@ page import="com.google.gson.JsonObject"%>

<%
Gson gsonObj = new Gson();
Map<Object,Object> map = null;
List<Map<Object,Object>> list = new ArrayList<Map<Object,Object>>();
String dataPoints = null;

try{
    Class.forName("com.mysql.jdbc.Driver");
    String user_name = "root";
    String password = "test123$";
    Connection con = DriverManager.getConnection("jdbc:mysql://192.168.1.7:3306/omaxdb", user_name,
            password);
    Statement statement = con.createStatement();
    String xVal, yVal;

    ResultSet resultSet = statement.executeQuery("select * from datapoints");

    while(resultSet.next()){
        xVal = resultSet.getString("x");
        yVal = resultSet.getString("y");
        map = new HashMap<Object,Object>(); map.put("x", Double.parseDouble(xVal)); map.put("y", Double.parseDouble(yVal)); list.add(map);
        dataPoints = gsonObj.toJson(list);
    }
    con.close();
}
catch(SQLException e){
    out.println("<div  style='width: 50%; margin-left: auto; margin-right: auto; margin-top: 200px;'>Could not connect to the database. Please check if you have mySQL Connector installed on the machine - if not, try installing the same.</div>");
    dataPoints = null;
}

%>

来自数据库的具有字符串值的JSP饼图

0 个答案: