使用jdbc操作mysql数据库

下面是本人在工作写的一个使用jdck操作mysql数据库的工具类，希望对大家有所帮助，如有错误或不妥之处，欢迎大家留言指正！

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.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MysqlDBHelper {
private static Connection conn = null;

// 获得连接对象
public static Connection getConn() {
String sDriverName = "com.mysql.jdbc.Driver";
String sDBUrl = "jdbc:mysql://127.0.0.1/phonebook";
String userName = "root"; // 默认用户名
String userPwd = "test"; // 密码
try {
Class.forName(sDriverName);
conn = DriverManager.getConnection(sDBUrl, userName, userPwd);
} catch (ClassNotFoundException e) {
throw new RuntimeException(e);
} catch (SQLException e) {
throw new RuntimeException(e);
}
return conn;
}

// 关闭连接
public static void closeConn(Statement statement) {
try {
statement.close();
statement = null;
conn.close();
conn = null;
} catch (Exception e) {
e.printStackTrace();
conn = null;
}
}

// 获得查询结果集
public static List<Map<String, Object>> queryList(String sql, Object[] params) {
getConn();
PreparedStatement ps = null;
List<Map<String, Object>> resultList = null;
try {
ps = conn.prepareStatement(sql);
if (params != null) {
for (int i = 0; i < params.length; i++) {
ps.setObject(i + 1, params[i]);
}
}
resultList = resultSetConvertList(ps.executeQuery());
} catch (SQLException e) {
throw new RuntimeException(e);
}
closeConn(ps);
return resultList;
}

// 用于对表的增删改操作
public static int update(String sql, Object[] params) {
getConn();
PreparedStatement ps = null;
int updateResult = 0;
try {
ps = conn.prepareStatement(sql);
if (params != null) {
for (int i = 0; i < params.length; i++) {
ps.setObject(i + 1, params[i]);
}
}
updateResult = ps.executeUpdate();
} catch (SQLException e) {
throw new RuntimeException(e);
}
closeConn(ps);
return updateResult;
}

// ResultSet转换成List<Map<String, Object>>
private static List<Map<String, Object>> resultSetConvertList(ResultSet resultSet) throws SQLException {
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
ResultSetMetaData rmd = resultSet.getMetaData();
int columnCount = rmd.getColumnCount();
while (resultSet.next()) {
Map<String, Object> rowData = new HashMap<String, Object>();
for (int i = 1; i <= columnCount; i++) {
rowData.put(rmd.getColumnName(i), resultSet.getObject(i));
}
list.add(rowData);
}
return list;
}
}

特别提醒大家，使用jdbc操作mysql数据还需要依赖mysql驱动包(mysql-connector-java-5.1.29.jar)。