mysql数据用json对象查询并且存入js数组

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环境：mysql5.0.22、eclipse j2ee LUNA

先看mysql数据

配置input.jsp查询条件的jsp文件（并且反馈回的页面也是input.jsp文件、ay数组遍历出的结果）

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form id="myForm">
userName:<input type="text" name="id" /> <input type="button"
value="submit" id="btn">
</form>
<div >
<div id="show_name"></div>
<div id="show_age"></div>
<div id="show_addr"></div>
</div>

</body>
<script type="text/javascript">

var oBtn = document.getElementById("btn");
oBtn.onclick = function() {
var oInput = document.getElementsByTagName("input")[0];
var id = oInput.value;
//location.href = "/servletFrame/qc?id=" + id;

var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
var json = JSON.parse(xmlhttp.responseText);
document.getElementById("show_name").innerHTML = json.name;
document.getElementById("show_age").innerHTML = json.age;
document.getElementById("show_addr").innerHTML = json.addr;
}
var ay=[json.name,json.age,json.addr];
for(var i=0;i<ay.length;i++){

document.write(ay[i]+" ");
}
}
xmlhttp.open("GET", "/servletFrame/QcServlet?id=" + id, true);
xmlhttp.send();

}
/* oBtn.onclick = function(){
document.getElementById("myForm").submit();
} */
</script>
</html>

配置QcServlet.java文件（注解方式）

@WebServlet("/QcServlet")
public class QcServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String id = request.getParameter("id");
Map<String, Object> map = new Jdbc828().get(id);

request.setAttribute("list", map);
String json = JSON.toJSONString(map);
response.setHeader("Content-type", "text/html;charset=UTF-8");
response.getWriter().write(json);

// request.getRequestDispatcher("/jsp/show.jsp")
// .forward(request, response);
}

}

配置数据库连接Jdbc.java

public class Jdbc828 {
// 声明Connection对象
java.sql.Connection con;
// 驱动程序名
String driver = "com.mysql.jdbc.Driver";
// URL指向要访问的数据库名mydata
String url = "jdbc:mysql://localhost:3306/zdy";
// MySQL配置时的用户名
String user = "root";
// MySQL配置时的密码
String password = "root";
// 结果集
java.sql.ResultSet rs;

java.sql.Statement statement=null;

public Map<String, Object> get(String userId) {
// 遍历查询结果集
try {
// 加载驱动程序
Class.forName(driver);
// 1.getConnection()方法，连接MySQL数据库！！
con = DriverManager.getConnection(url, user, password);
// 2.创建statement类对象，用来执行SQL语句！！
statement = con.createStatement();
// 要执行的SQL语句
String sql = "SELECT * FROM student WHERE idcard="+userId;
// 3.ResultSet类，用来存放获取的结果集！！
rs = statement.executeQuery(sql);
List<Map>list=new ArrayList<Map>();
Map<String, Object> m = null;
while (rs.next()) {
String idcard = rs.getString("idcard");
String name = rs.getString("name");
String age = rs.getString("age");
String gender = rs.getString("gender");
String addr = rs.getString("addr");
m = new HashMap<String, Object>();
m.put("idcard", idcard);
m.put("name", name);
m.put("age", age);
m.put("gender", gender);
m.put("addr", addr);
list.add(m);
}
return m;
} catch (Exception e) {
System.out.println("Sorry,can`t find the Driver!");
} finally {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
statement.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

return null;
}
}

注意查询结果，并不是json对象输出的结果，而是ay数组的遍历出来的结果

这里面用的都是statement看本帖的同学可以考虑下这个对象的缺点同样可以试着将它换成什么。。。

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