JdbcUtils
时间：2021-07-01 10:21:17
帮助过：15人阅读
java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
public class JdbcUtils {
private static volatile JdbcUtils jdbcUtils =
null;
private static Connection conn =
null;
private static ResultSet rs =
null;
private static PreparedStatement ps =
null;
static String url =
null;
static String user =
null;
static String password =
null;
static {
Properties p =
new Properties();
try {
p.load(JdbcUtils.class.getClassLoader().getResourceAsStream(
"com/mysql/properties/mysql.properties"
));
url = p.getProperty("url"
);
user = p.getProperty("user"
);
password = p.getProperty("password"
);
} catch (IOException e) {
e.printStackTrace();
}
}
private JdbcUtils() {
getConn();
}
private void getConn() {
try {
Class.forName("com.mysql.jdbc.Driver"
);
conn =
DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
public static JdbcUtils newInstance() {
if (jdbcUtils ==
null) {
synchronized (JdbcUtils.
class) {
if (jdbcUtils ==
null) {
jdbcUtils =
new JdbcUtils();
}
}
}
return jdbcUtils;
}
public int insert(String sql, Object... obj) {
int result = 0
;
try {
ps =
conn.prepareStatement(sql);
int index = 1
;
for (Object o : obj) {
ps.setObject(index++
, o);
}
result =
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
return -1
;
} finally {
close();
}
return result;
}
public int Delete(String sql, Object... obj) {
int result = 0
;
try {
ps =
conn.prepareStatement(sql);
int index = 1
;
for (Object o : obj) {
ps.setObject(index++
, o);
}
result =
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
return -1
;
} finally {
close();
}
return result;
}
public int update(String sql, Object... obj) {
int result = 0
;
try {
ps =
conn.prepareStatement(sql);
int index = 1
;
for (Object o : obj) {
ps.setObject(index++
, o);
}
result =
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
return -1
;
} finally {
close();
}
return result;
}
public List<Map<String, Object>>
select(String sql, Object... obj) {
List<Map<String, Object>> list =
new ArrayList<Map<String, Object>>
();
try {
ps =
conn.prepareStatement(sql);
int index = 1
;
for (Object o : obj) {
ps.setObject(index++
, o);
}
rs =
ps.executeQuery();
ResultSetMetaData rsd =
rs.getMetaData();
int length =
rsd.getColumnCount();
// System.out.println(length);
while (rs.next()) {
Map<String, Object> m =
new HashMap<String, Object>
();
for (
int i = 1; i <= length; i++
) {
m.put(rsd.getColumnName(i), rs.getObject(i));
}
// System.out.println(m.size());
list.add(m);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
}
return list;
}
private void close() {
try {
if (rs !=
null) {
rs.close();
}
if (ps !=
null) {
ps.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
JdbcUtils
JdbcUtils
标签：rac public password str final div pre nts put
