Java Mysql--链接数据库，数据库字段比较

连接库操作：

 package com.qa.xxx;

 import org.springframework.stereotype.Component;
 import java.lang.reflect.Method;
 import java.sql.*;
 import java.util.ArrayList;
 import java.util.List;

 @Component
 public class MySQLUtil {

     private static final String MYSQL_DRIVER = "com.mysql.cj.jdbc.Driver";

     private static ThreadLocal<Connection> threadLocal = new ThreadLocal<>();

     public static Connection getMysqlConnection(String url, String userName, String userPassword){
         Connection connection = threadLocal.get();
         if(null == connection){
             try {
                 Class.forName(MYSQL_DRIVER);
                 connection = DriverManager.getConnection(url, userName, userPassword);
                 return connection;
             } catch (ClassNotFoundException e) {
                 e.printStackTrace();
             } catch (SQLException e) {
                 e.printStackTrace();
             }
         }
         return connection;
     }

     /**
      * 查询定义的相应的数据库对象bean值
      * @param url
      * @param userName
      * @param userPassword
      * @param sql
      * @param t
      * @param objs
      * @param <T>
      * @return
      */
     public static <T> List<T> excuteQuery(String url, String userName, String userPassword, String sql, T t, Object...objs){
         List<T> list = new ArrayList<>();
         Connection connection = null;
         PreparedStatement ps = null;
         ResultSet rs = null;
         try{
             connection = MySQLUtil.getMysqlConnection(url,userName,userPassword);
             ps = connection.prepareStatement(sql);
             //占位符赋值
             if(null != objs){
                 for(int i=0; i<objs.length; i++){
                     ps.setObject((i+1), objs[i]);
                 }
             }
             rs = ps.executeQuery();
             ResultSetMetaData rm = rs.getMetaData();
             int columnCount = rm.getColumnCount();
             while (rs.next()){
                 Class<? extends Object> clzss = t.getClass();
                 T newInstance = (T)clzss.newInstance();
                 for(int i=1; i<=columnCount; i++){
                     String columnName = rm.getColumnName(i);
                     String methodName = "set" + columnName.substring(0,1).toUpperCase() + columnName.substring(1);
                     String columnClassName = rm.getColumnClassName(i);
                     Method method = clzss.getDeclaredMethod(methodName, Class.forName(columnClassName));
                     method.invoke(newInstance, rs.getObject(columnName));
                 }
                 list.add(newInstance);
             }

         }catch (Exception e){
             e.printStackTrace();
         }finally {
             MySQLUtil.close(ps);
         }
         return list;
     }

     /**
      * 查询单个字段值
      * @param url
      * @param userName
      * @param userPassword
      * @param sql
      * @param objs
      * @return
      */
     public static List<String> excuteOneFieldQuery(String url, String userName, String userPassword, String sql, Object...objs){
         List<String> list = new ArrayList<>();
         Connection connection = null;
         PreparedStatement ps = null;
         ResultSet rs = null;
         try{
             connection = MySQLUtil.getMysqlConnection(url,userName,userPassword);
             ps = connection.prepareStatement(sql);
             //占位符赋值
             if(null != objs){
                 for(int i=0; i<objs.length; i++){
                     ps.setObject((i+1), objs[i]);
                 }
             }
             rs = ps.executeQuery();
             ResultSetMetaData rm = rs.getMetaData();
             int columnCount = rm.getColumnCount();
             while (rs.next()){
                 list.add(rs.getString(1));
             }
         }catch (Exception e){
             e.printStackTrace();
         }finally {
             MySQLUtil.close(ps);
         }
         return list;
     }

     /**
      * 增删改
      * @param url
      * @param userName
      * @param userPassword
      * @param sql
      * @param objs
      * @return
      */
     public static Integer executeDML(String url, String userName, String userPassword, String sql, Object...objs){
         Connection connection = null;
         PreparedStatement ps = null;
         Integer integer = 0;
         try{
             connection = MySQLUtil.getMysqlConnection(url,userName,userPassword);
             ps = connection.prepareStatement(sql);
             if(null != objs){
                 for(int i=0; i<objs.length; i++){
                     ps.setObject((i+1), objs[i]);
                 }
             }
             integer = ps.executeUpdate();
         }catch (SQLException e){
             e.printStackTrace();
         }finally {
             MySQLUtil.close(ps);
         }
         return integer;
     }

     /**
      * 关闭操作
      * @param t
      * @param <T>
      */
     private static <T>void close(T...t){
         //循环关流
         for(T tmp:t) {
             //关闭流对象
             if(tmp instanceof AutoCloseable) {
                 try {
                     ((AutoCloseable)tmp).close();
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
         }
     }

 }

数据库字段比对：

 package com.qa.xxx;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Component;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 @Component
 public class DataCompareUtil {

     private final static Logger logger = LoggerFactory.getLogger(DataCompareUtil.class);

     /**
      * 数据库表查询字段比对
      * @param obj1 老查询获取的数据
      * @param obj2 新查询获取的数据
      * @param list 要对比的字段
      * @return 返回<字段名称，原值x 新值x>
      */
     public static Map<String, String> compareObject(Object obj1, Object obj2, List<String> list){
         Map<String, String> map = new HashMap<>();
         if(null != list && !list.isEmpty()){
             for(String field : list){
                 String firstLetter = field.substring(0,1).toUpperCase();
                 String getter = "get" + firstLetter + field.substring(1);
                 try {
                     Method method1 = obj1.getClass().getMethod(getter, new Class[]{});
                     Method method2 = obj2.getClass().getMethod(getter, new Class[]{});
                     Object oldValue = method1.invoke(obj1, new Object[] {});
                     Object newValue = method2.invoke(obj2, new Object[] {});
                     map.put(field, "原值：" + oldValue.toString() + " 新值：" + newValue.toString());
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
             return map;
         }else {
             Class clazz = obj2.getClass();
             Field[] fields = clazz.getDeclaredFields();
             for(Field field : fields){
                 String fieldName = field.getName();
                 String firstLetter = fieldName.substring(0,1).toUpperCase();
                 String getter = "get" + firstLetter + fieldName.substring(1);
                 try {
                     Method method1 = obj1.getClass().getMethod(getter, new Class[]{});
                     Method method2 = obj2.getClass().getMethod(getter, new Class[]{});
                     Object oldValue = method1.invoke(obj1, new Object[] {});
                     Object newValue = method2.invoke(obj2, new Object[] {});
                     map.put(fieldName, "原值：" + oldValue.toString() + " 新值：" + newValue.toString());
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
             return map;
         }
     }

 }