java连接mysql数据库_MySQL

在此与大家分享一个java连接mysql数据库的封装类

public class DB {

static {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}

private DB() {}

public static Connection getConn() {
Connection conn = null;
try{
conn = DriverManager.getConnection("jdbc:mysql://localhost/mydatabase?" + "user=root&password=root");
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}

public static void closeConn(Connection conn) {
try {
if(conn != null) {
conn.close();
conn = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}

public static Statement getStmt(Connection conn){
Statement stmt = null;
try {
stmt = conn.createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
return stmt;
}

public static void closeStmt(Statement stmt) {
try {
if(stmt != null) {
stmt.close();
stmt = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
//根据conn,sql得到pStmt
public static PreparedStatement getPStmt(Connection conn, String sql){
PreparedStatement pStmt = null;
try {
pStmt = conn.prepareStatement(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return pStmt;
}
//根据stmt,sql得到结果集
public static ResultSet executeQuery(Statement stmt, String sql){
ResultSet rs = null;
try {
rs = stmt.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}

//根据conn,sql得到结果集
public static ResultSet executeQuery(Connection conn, String sql){
ResultSet rs = null;
try {
rs = conn.createStatement().executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}

public static void closeResultSet(ResultSet rs) {
try {
if(rs != null) {
rs.close();
rs = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}