Java 连接到 SQL Anywhere 17

Question

我正在开展一个学校项目，我必须连接到在 SQL Anywhere 17 中完成的数据库，但我不断收到以下错误:

No suitable driver found for jdbc:sqlanywhere:Tds:localhost:2638?eng="DBNAME".

欢迎任何帮助。

这是执行连接的类的代码。

package model;

import java.sql.*;

public class DBConnection {

    public class ConnectionHandler {
        ResultSet r;
        Statement s;
        String returnStatus;
    }

    private String db, user, passwd;
    private String dbUrl;
    private Connection conn;

    public DBConnection(String db, String user, String passwd, Object openserver, String databasepath) {
        this.db = db;
        this.user = user;
        this.passwd = passwd;

        dbUrl = "jdbc:sqlanywhere:Tds:localhost:2638?eng=" + db;

        try {
            conn = DriverManager.getConnection(dbUrl, user, passwd);
            conn.setAutoCommit(false);
        } catch (Exception e) {
            System.out.println(e);
            Boolean openServer = (Boolean) openserver;
            if (openServer.booleanValue())
                try {
                    String engcommand = "dbeng12 " + databasepath + db + ".db";
                    Runtime.getRuntime().exec(engcommand);
                    long t0, t1;
                    t0 = System.currentTimeMillis();
                    do {
                        t1 = System.currentTimeMillis();
                    } while (t1 - t0 < 5000);
                    conn = DriverManager.getConnection(dbUrl, user, passwd);
                    conn.setAutoCommit(false);
                } catch (Exception ex) {
                    System.out.println("Unable to start server. " + ex);
                }
        }
    }

    public void updateStatement(String sql, ConnectionHandler ch) {
        Integer result = new Integer(0);
        String message = null;

        if (sql.trim().substring(0, 1).equalsIgnoreCase("U"))
            message = "Number of rows updated: ";
        else if (sql.trim().substring(0, 1).equalsIgnoreCase("I"))
            message = "Number of rows inserted: ";
        else
            message = " ";

        try {
            ch.s = conn.createStatement();
            result = new Integer(ch.s.executeUpdate(sql));
            ch.returnStatus = message + result;
        } catch (Exception e) {
            System.out.println("Unable to execute the insert/update/delete statement. " + e);
            ch.returnStatus = "Error:" + e.toString();
        }
    }

    public void returnResultSetSelectStatement(String sql, int resultsetType, ConnectionHandler ch) {
        ch.r = null;
        try {
            if (resultsetType == 1)
                ch.s = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_UPDATABLE);
            else
                ch.s = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
            ch.r = ch.s.executeQuery(sql);

        } catch (Exception e) {
            ch.returnStatus = e.toString();
            System.out.println("Unable to execute the returnSelectStatement. " + e);
        }
    }

}

Answer 1

您需要将sajdbc4.jar添加到程序的类路径中。如果您使用的是 NetBeans 或 Eclipse 等 IDE，则可以添加 sajdbc4.jar 作为依赖库，NetBeans/Eclipse 会自动将其添加到类路径中。

如果您从命令行运行上述程序，请将 sajdbc4.jar 复制到上述 Java 程序所在的文件夹，然后使用以下命令编译该文件(这将添加 sajdbc4.jar 到类路径)，

javac -classpath ./sajdbc4.jar DbConnection.java

使用以下命令运行Java程序(sajdbc4.jar已添加到类路径中)，

java -classpath "./sajdbc4.jar;." DbConnection

或者，如果您使用 Maven 构建项目，您也可以添加 Maven 依赖项。