怎样测试java连接数据库是否成功

你好，判断连接是否成功，可以判断conn是否为空，或者是否有异常抛出

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try{

Connection

con

=

DriverManager.getConnection(url

,

username

,

password

)

}catch(SQLException

se){

System.out.println("数据库连接失败！")

se.printStackTrace()

}

希望可以帮助到你

package jdbc

import java.io.IOException

import java.io.InputStream

import java.sql.Connection

import java.sql.DriverManager

import java.sql.ResultSet

import java.sql.SQLException

import java.util.Properties

import java.sql.PreparedStatement

/**

* jdbc连接数据库， *** 作数据库的实体类

*

* @author yzm

*

*/

public class MySQLJDBCConnectionUtil {

private static String url// url路径

private static String driver// 驱动

private static String username// 用户名

private static String password// 密码

static {

try {

InputStream is = MySQLJDBCConnectionUtil.class.getClassLoader()

.getResourceAsStream("jdbc/jdbc.properties")

Properties prop = new Properties()

prop.load(is)

is.close()

url = prop.getProperty("url")

driver = prop.getProperty("driver")

username = prop.getProperty("username")

password = prop.getProperty("password")

Class.forName(driver)

} catch (IOException e) {

e.printStackTrace()

} catch (ClassNotFoundException e) {

e.printStackTrace()

}

}

/**

* 获得连接

*

* @return

* @throws SQLException

*/

public static Connection getConnection() throws SQLException {

return DriverManager.getConnection(url, username, password)

}

/**

* 关闭连接

*

* @param con

*/

public static void closeCon(Connection con) {

try {

if (con != null) {

con.close()

}

} catch (SQLException e) {

e.printStackTrace()

}

}

/**

* 关闭预编译

*

* @param stmt

*/

public static void closeStmt(PreparedStatement stmt) {

try {

if (stmt != null) {

stmt.close()

}

} catch (SQLException e) {

e.printStackTrace()

}

}

/**

* 关闭结果集

*

* @param rs

*/

public static void closeRs(ResultSet rs) {

try {

if (rs != null) {

rs.close()

}

} catch (SQLException e) {

e.printStackTrace()

}

}

/**

* 关闭没有结果集的连接

*

* @param con

* @param stmt

*/

public static void close(Connection con, PreparedStatement stmt) {

closeCon(con)

closeStmt(stmt)

}

/**

* 关闭有结果集的连接

*

* @param con

* @param stmt

* @param rs

*/

public static void close(Connection con, PreparedStatement stmt,

ResultSet rs) {

close(con, stmt)

closeRs(rs)

}

/**

* 测试主方法

*

* @param args

* @throws SQLException

*/

public static void main(String[] args) throws SQLException {

Connection c = getConnection()

System.out.println(c)

}

}

import java.sql.*

public class getMetaData {

public static void main(String[] args) {

String driverClassName = "oracle.jdbc.OracleDriver"

String url = "jdbc:oracle:thin:@192.101.101.101:1521:orcl"

String password = "test"

String user= "test"

try {

Class.forName(driverClassName)

} catch (ClassNotFoundException ex) {

System.out.println("加载错误！")

}

Connection conn = null

try {

conn = DriverManager.getConnection(url, user, password)

System.out.println("连接成功")

String sql = "select id_ tid,name_ tname1 ,memo remark from tc"

PreparedStatement ps=conn.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY)

ResultSet rs=ps.executeQuery()

ResultSetMetaData md = ps.getMetaData() //ps.getMetaData()//

for (int i = 1i <= md.getColumnCount()i++) {

System.out.println("name:"+md.getColumnName(i)+" label:"+md.getColumnLabel(i))

}

sql = "select max(id_) tid,name_ tname1 ,memo remark from tc group by name_,memo"

ps=conn.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY)

rs=ps.executeQuery()

md = rs.getMetaData() //ps.getMetaData()//

for (int i = 1i <= md.getColumnCount()i++) {

System.out.println("name:"+md.getColumnName(i)+" label:"+md.getColumnLabel(i))

}

} catch (SQLException ex1) {

System.out.println(ex1)

System.out.println("失败")

}

}

}

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