我从我的代码中收到cannot find symbol
错误。有谁知道什么会导致这个问题?使用Class.forName()时出现“找不到符号”问题()
的代码是:
// Register JDBC driver
Class.forName("net.sourceforge.jtds.jdbc.Driver");
和误差输出为:
blah.java:314: cannot find symbol
symbol : method forName(java.lang.String)
location: class java.lang.Class
Class.forName("net.sourceforge.jtds.jdbc.Driver");
^
1 error
//STEP 1. Import required packages
import java.sql.*;
public class JDBCExample {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.sql.jdbc.Driver";
static final String DB_URL = (":jdbc:jtds:sqlserver://localhost:1433/tempdb");
// Database credentials
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
//STEP 2: Register JDBC driver
Class.forName("net.sourceforge.jtds.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
//STEP 4: Execute a query
System.out.println("Creating database...");
stmt = conn.createStatement();
String sql = "CREATE DATABASE ";
stmt.executeUpdate(sql);
System.out.println("Database created successfully...");
}catch(SQLException se){
//Handle errors for JDBC
se.printStackTrace();
}catch(Exception e){
//Handle errors for Class.forName
e.printStackTrace();
}finally{
//finally block used to close resources
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}// nothing we can do
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
}//end try
System.out.println("Goodbye");
}//end main
}//end JDBCExample
请提出问题,请不要只发布错误消息。 – luke 2010-06-14 03:51:17
@joseph,我试图清理这个问题,使它更加负责任。如果我错误地改变了意图,请告诉我。我猜测你真的在使用GWT吗? – paxdiablo 2010-06-14 04:02:09
@paxdiablo:这个问题已经过度地编辑了。你能否改回它来反映第一个Class.forName ...是代码的事实,并且从method ... onward开始的所有内容都是编译器错误输出? – 2010-06-14 04:51:52