使用JSP提交表單提交

我正在嘗試創建一個將插入通過表單提交的記錄的JSP。但是，我試圖確保它連接，並使用mySQL select語句來檢索數據。我發佈了下面的錯誤。我不知道爲什麼我得到這個錯誤。到目前爲止，我有這個使用JSP提交表單提交

<%@ page import ="java.sql.*" %> 
<% 
String url = "jdbc:mysql//sql.njit.edu:3306/user"; 
String user = "u"; 
String pass = "p"; 
String classPath = "com.mysql.jdbc.Driver"; 
Connection conn = null; 
Statement stmt = null; 
ResultSet rs = null; 

try{ 
    Class.forName(classPath); 
    conn = DriverManager.getConnection(url, user, pass); 
} catch(Exception e){ 
    e.printStackTrace(); 
} 

stmt = conn.createStatement(); 

String query = "SELECT * FROM Music"; 

try{ 
    rs = stmt.executeQuery(query); 
    while(rs.next()){ 
     out.println(rs.getString("song")); 
    } 
}catch(SQLException e){ 
    e.printStackTrace(); 
} 
finally { 
    try { 
     if (stmt != null) 
      stmt.close(); 
     if (rs != null) 
      rs.close(); 
     if (conn != null) 
      conn.close(); 
    }catch (SQLException e) { 
     e.printStackTrace(); 
    } 
} 
%>

我收到以下錯誤

Stacktrace: 
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:451) 
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373) 
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:321) 
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:257) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:729) 

root cause 

java.lang.NullPointerException 
org.apache.jsp.insert_jsp._jspService(insert_jsp.java:64) 
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:729) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:321) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:257) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

來源

2013-04-03 user1709294

你的JDBC URL格式錯誤。它應該像

jdbc:mysql//sql.school.edu:3306/user

來源

2013-04-03 03:15:08

我仍然得到錯誤。 – user1709294

那麼，不要在catch中打印堆棧跟蹤，而是打印catch塊標識符（在獲取conn期間sat'失敗）並找出失敗的位置。這會給你更多的見解。 –

使用JSP提交表單提交

回答

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