使用加载属性文件

Question

请查看以下MSSQL Server 2005代码。

属性文件

driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
url=jdbc:sqlserver://127.0.0.1:1433;databaseName=LibMgmtSys
user=sa
password=passwrod

连接文件

public class DBConnection {

    static Properties dbproperties;

    public static Connection getConnection() throws Exception {
        Connection conn = null;
        InputStream dbInputStream = null;
        dbInputStream = DBConnection.class.getResourceAsStream("jdbc.properties");

        try {
            dbproperties.load(dbInputStream);
            Class.forName(dbproperties.getProperty("driver"));
            conn = DriverManager.getConnection(dbproperties.getProperty("url"),
                    dbproperties.getProperty("user"),
                    dbproperties.getProperty("password"));
        } catch (Exception exp) {
            System.out.println("error : " + exp);
        }

        return conn;
    }
}

当我尝试执行dbproperties.load（dbInputStream）时，上面的代码给了我一个NullPointException。我做错了吗？

Answer 1

您没有实例化dbproperties，因此当您尝试取消引用它时，它会为空（dbproperties.load(dbInputStream);）。将其更改为：

    try {
        dbproperties = new Properties();
        dbproperties.load(dbInputStream);