package address.dao;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.io.InputStream;
import java.util.Properties;public class ConnectionManager {
public static Connection getConnection() {
Connection dbConnection = null;
try {
Properties p = new Properties();
Class c=p.getClass();
InputStream is = c.getResourceAsStream("/db.properties");
p.load(is);
if (is != null)
is.close();
String driverClassName = p.getProperty("driver");
String url = p.getProperty("url");
String user = p.getProperty("user");
String password = p.getProperty("password"); Class.forName(driverClassName);
} catch (Exception e) {
e.printStackTrace();
}
return dbConnection;
} public static void closeConnection(Connection dbConnection) {
try {
if (dbConnection != null && !dbConnection.isClosed()) {
dbConnection.close();
System.out.println("数据库连接已关闭");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
package address;import java.sql.Connection;
import java.sql.SQLException;import address.dao.ConnectionManager;
import java.sql.PreparedStatement;public class App { public static void main(String[] args) {
Connection dbConnection = ConnectionManager.getConnection();
try {
String sqlStr = "insert into [user] (username,password) values('abc','123')";
PreparedStatement ps = dbConnection.prepareStatement(sqlStr);
ps.executeUpdate();
sqlStr = "insert into [user] (username,password) values(?,?)";
ps = dbConnection.prepareStatement(sqlStr);
ps.setObject(1, "bbb");
ps.setObject(2, "222");
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} finally {
ConnectionManager.closeConnection(dbConnection);
}
}}
数据库JavaString类URL
import java.sql.DriverManager;
import java.sql.SQLException;
import java.io.InputStream;
import java.util.Properties;public class ConnectionManager {
public static Connection getConnection() {
Connection dbConnection = null;
try {
Properties p = new Properties();
Class c=p.getClass();
InputStream is = c.getResourceAsStream("/db.properties");
p.load(is);
if (is != null)
is.close();
String driverClassName = p.getProperty("driver");
String url = p.getProperty("url");
String user = p.getProperty("user");
String password = p.getProperty("password"); Class.forName(driverClassName);
} catch (Exception e) {
e.printStackTrace();
}
return dbConnection;
} public static void closeConnection(Connection dbConnection) {
try {
if (dbConnection != null && !dbConnection.isClosed()) {
dbConnection.close();
System.out.println("数据库连接已关闭");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
package address;import java.sql.Connection;
import java.sql.SQLException;import address.dao.ConnectionManager;
import java.sql.PreparedStatement;public class App { public static void main(String[] args) {
Connection dbConnection = ConnectionManager.getConnection();
try {
String sqlStr = "insert into [user] (username,password) values('abc','123')";
PreparedStatement ps = dbConnection.prepareStatement(sqlStr);
ps.executeUpdate();
sqlStr = "insert into [user] (username,password) values(?,?)";
ps = dbConnection.prepareStatement(sqlStr);
ps.setObject(1, "bbb");
ps.setObject(2, "222");
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
} finally {
ConnectionManager.closeConnection(dbConnection);
}
}}
数据库JavaString类URL
什么警告,貌似不应该有警告。。InputStream is = new Properties().getClass().getResourceAsStream("/db.properties");