JAVA JDBC-Mysql操作类

package com.yunti.utils;import java.lang.reflect.Field;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;public class JdbcUtils {private final static String URL = "jdbc:mysql://127.0.0.1:3306/network";private final static String USER = "root";private final static String PWD  = "";private final static String Driver = "com.mysql.jdbc.Driver";private Connection connection;private PreparedStatement prepareStatement;private ResultSet resultSet;public JdbcUtils() {try {Class.forName(Driver);connection = DriverManager.getConnection(URL,USER,PWD);} catch (Exception e) {e.printStackTrace();}}/** * 多条查询 * @param sql * @param params * @return * @throws SQLException */public List<Map<String,Object>> findMoreByStatement(String sql,List<Object> params) throws SQLException{List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();prepareStatement = connection.prepareStatement(sql);if(params!=null&&!params.isEmpty()){for(int i=0;i<params.size();i++){prepareStatement.setObject(i+1, params.get(i));}}resultSet = prepareStatement.executeQuery();ResultSetMetaData rsmd = resultSet.getMetaData();while(resultSet.next()){Map<String,Object> map = new HashMap<String,Object>();for(int i=1;i<=rsmd.getColumnCount();i++){String column_name  = rsmd.getColumnName(i);Object column_value = resultSet.getObject(column_name);if(column_value == null){column_value = "";}map.put(column_name, column_value);}list.add(map);}return list;}/** * 单条查询 * @param sql * @param params * @return * @throws SQLException */public Map<String,Object> findByStatement(String sql,List<Object> params) throws SQLException{Map<String,Object> map = new HashMap<String,Object>();prepareStatement = connection.prepareStatement(sql);if(params!=null&&!params.isEmpty()){for(int i=0;i<params.size();i++){prepareStatement.setObject(i+1, params.get(i));}}resultSet = prepareStatement.executeQuery();ResultSetMetaData rsmd = resultSet.getMetaData();while(resultSet.next()){for(int i=1;i<=rsmd.getColumnCount();i++){String column_name  = rsmd.getColumnName(i);Object column_value = resultSet.getObject(column_name);if(column_value == null){column_value = "";}map.put(column_name, column_value);}}return map;}/** * 反射单条查询 * @param sql * @param params * @param c * @return * @throws Exception */public <T> T findByStatement(String sql,List<Object> params,Class<T> c) throws Exception{T resultObj = null;prepareStatement = connection.prepareStatement(sql);if(params!=null&&!params.isEmpty()){for(int i=0;i<params.size();i++){prepareStatement.setObject(i+1, params.get(i));}}resultSet = prepareStatement.executeQuery();ResultSetMetaData rsmd = resultSet.getMetaData();while(resultSet.next()){resultObj = c.newInstance();for(int i=1;i<=rsmd.getColumnCount();i++){String column_name  = rsmd.getColumnName(i);Object column_value = resultSet.getObject(column_name);if(column_value == null){column_value = "";}Field field = c.getDeclaredField(column_name);field.setAccessible(true);field.set(resultObj, column_value);}}return resultObj;}/** * 反射多条查询 * @param sql * @param params * @param c * @return * @throws Exception */public <T> List<T> findMoreByStatement(String sql,List<Object> params,Class<T> c) throws Exception{List<T> list = new ArrayList<T>();prepareStatement = connection.prepareStatement(sql);if(params!=null&&!params.isEmpty()){for(int i=0;i<params.size();i++){prepareStatement.setObject(i+1, params.get(i));}}resultSet = prepareStatement.executeQuery();ResultSetMetaData rsmd = resultSet.getMetaData();while(resultSet.next()){T resultObj = c.newInstance();for(int i=1;i<=rsmd.getColumnCount();i++){String column_name  = rsmd.getColumnName(i);Object column_value = resultSet.getObject(column_name);if(column_value == null){column_value = "";}Field field = c.getDeclaredField(column_name);field.setAccessible(true);field.set(resultObj, column_value);}list.add(resultObj);}return list;}/** * 数据增删改 * @param sql * @param params * @return * @throws SQLException */public boolean updateByPrepareStatement(String sql,List<Object> params) throws SQLException{boolean flag = false;int result = -1;prepareStatement = connection.prepareStatement(sql);if(params != null && !params.isEmpty()){for (int i = 0; i < params.size(); i++) {prepareStatement.setObject(i+1, params.get(i));}}result = prepareStatement.executeUpdate();flag = result > 0 ? true : false;return flag;} /** * 资源释放 */public void releaseConn(){if(prepareStatement != null){try {connection.close();prepareStatement.close();} catch (SQLException e) {e.printStackTrace();}}}}