利用JAVA反射,读取数据库表名,自动生成对应实体类的操作

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.Date;
 
/**
 * 从数据库表反射出实体类，自动生成实体类
 * 
 * @author Zero
 *
 */
public class SqlHelper {
	//基本数据配置
	private String packageOutPath = "com.xxx.entity.system";// 指定实体生成所在包的路径
	private String authorName = "Zero";// 作者名字
	private String tablename = "xxx";// 表名
	private String[] colnames; // 列名数组
	private String[] colTypes; // 列名类型数组
	private String version = "V0.01"; // 版本
	private int[] colSizes; // 列名大小数组
	private boolean f_util = false; // 是否需要导入包java.util.*
	private boolean f_sql = false; // 是否需要导入包java.sql.*
	private boolean f_lang = false; // 是否需要导入包java.sql.*
	private String defaultPath = "/src/main/java/";
	// 数据库连接
	private static final String URL = "jdbc:jtds:sqlserver://192.168.29.128:1433/xxx";
	private static final String NAME = "sa";
	private static final String PASS = "xxx";
	private static final String DRIVER = "net.sourceforge.jtds.jdbc.Driver";
 
	/*
	 * 构造函数
	 */
	public SqlHelper() {
		// 创建连接
		Connection con;
		// 查要生成实体类的表
		String sql = "select * from " + tablename;
		PreparedStatement pStemt = null;
		try {
			try {
				Class.forName(DRIVER);
			} catch (ClassNotFoundException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			con = DriverManager.getConnection(URL, NAME, PASS);
			pStemt = con.prepareStatement(sql);
			ResultSetMetaData rsmd = pStemt.getMetaData();
			int size = rsmd.getColumnCount(); // 统计列
			colnames = new String[size];
			colTypes = new String[size];
			colSizes = new int[size];
			for (int i = 0; i = 'a' && ch[0] <= 'z') {
			ch[0] = (char) (ch[0] - 32);
		}
 
		return new String(ch);
	}
 
	/**
	 * 功能：获得列的数据类型
	 * 
	 * @param sqlType
	 * @return
	 */
	private String sqlType2JavaType(String sqlType) {
 
		if (sqlType.equalsIgnoreCase("bit")) {
			return "Boolean";
		} else if (sqlType.equalsIgnoreCase("decimal") || sqlType.equalsIgnoreCase("money")
				|| sqlType.equalsIgnoreCase("smallmoney") || sqlType.equalsIgnoreCase("numeric")
				|| sqlType.equalsIgnoreCase("bigint")) {
			return "Long";
		} else if (sqlType.equalsIgnoreCase("float")) {
			return "Double";
		} else if (sqlType.equalsIgnoreCase("int") || sqlType.equalsIgnoreCase("int identity")) {
			return "Integer";
		} else if (sqlType.equalsIgnoreCase("image") || sqlType.equalsIgnoreCase("varbinary(max)")
				|| sqlType.equalsIgnoreCase("varbinary") || sqlType.equalsIgnoreCase("udt")
				|| sqlType.equalsIgnoreCase("timestamp") || sqlType.equalsIgnoreCase("binary")) {
			return "Byte[]";
		} else if (sqlType.equalsIgnoreCase("nchar") || sqlType.equalsIgnoreCase("nvarchar(max)")
				|| sqlType.equalsIgnoreCase("nvarchar") || sqlType.equalsIgnoreCase("nvarchar(ntext)")
				|| sqlType.equalsIgnoreCase("uniqueidentifier") || sqlType.equalsIgnoreCase("xml")
				|| sqlType.equalsIgnoreCase("char") || sqlType.equalsIgnoreCase("varchar(max)")
				|| sqlType.equalsIgnoreCase("text") || sqlType.equalsIgnoreCase("varchar")) {
			return "String";
		} else if (sqlType.equalsIgnoreCase("real")) {
			return "Float";
		} else if (sqlType.equalsIgnoreCase("smallint") || sqlType.equalsIgnoreCase("tinyint")) {
			return "Short";
		} else if (sqlType.equalsIgnoreCase("date") || sqlType.equalsIgnoreCase("datetime")
				|| sqlType.equalsIgnoreCase("time") || sqlType.equalsIgnoreCase("datetime2")) {
			return "Date";
		} else {
			System.out.println("数据类型异常，类型为：" + sqlType);
		}
 
		return null;
	}
 
	/**
	 * 出口 TODO
	 * 
	 * @param args
	 */
	public static void main(String[] args) {
 
		new SqlHelper();
 
	}
}

import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.Table;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
 
/**
 * @author caizw
 * @createDate 2018/2/8
 * @description 反射工具类
 */
public class ReflectUtils {
 
  /**
   * 获取实体类主键
   *
   * @param clazz
   * @return
   */
  public static Field getIdField(Class<&＃63;> clazz) {
    Field[] fields = clazz.getDeclaredFields();
    Field item = null;
    for (Field field : fields) {
      Id id = field.getAnnotation(Id.class);
      if (id != null) {
        field.setAccessible(true);
        item = field;
        break;
      }
    }
    if (item == null) {
      Class<&＃63;> superclass = clazz.getSuperclass();
      if (superclass != null) {
        item = getIdField(superclass);
      }
    }
    return item;
  }
 
  /**
   * 根据主键名称获取实体类主键属性值
   *
   * @param clazz
   * @param pkName
   * @return
   */
  public static Object getPkValueByName(Object clazz, String pkName) {
    try {
      String firstLetter = pkName.substring(0, 1).toUpperCase();
      String getter = "get" + firstLetter + pkName.substring(1);
      Method method = clazz.getClass().getMethod(getter, new Class[]{});
      Object value = method.invoke(clazz, new Object[]{});
      return value;
    } catch (Exception e) {
      return null;
    }
  }
 
  /**
   * 通过反射将 class1不为空的值赋值给class2
   *
   * @param class1
   * @param class2
   * @throws Exception
   */
  public static void reflectClass1ToClass2(Object class1, Object class2) throws Exception {
    Field[] field = class1.getClass().getDeclaredFields();
    for (int i = 0; i  getColumnName(Class<&＃63;> clazz) {
    Map map = new ConcurrentHashMap<>();
    Field[] fields = clazz.getDeclaredFields();
    for (Field field : fields) {
      if (field.isAnnotationPresent(Column.class)) {
        /**
         * 获取字段名
         */
        Column declaredAnnotation = field.getDeclaredAnnotation(Column.class);
        String column = declaredAnnotation.name();
        map.put("fieldNames", field.getName());
        map.put("column", column);
        break;
      }
    }
    return map;
  }
 
  /**
   * 通过获取类上的@Table注解获取表名称
   *
   * @param clazz
   * @return
   */
  public static Map getTableName(Class<&＃63;> clazz) {
    Map map = new ConcurrentHashMap<>();
    Table annotation = clazz.getAnnotation(Table.class);
    String name = annotation.name();
    String className = clazz.getSimpleName();
    map.put("tableName", name);
    map.put("className", className);
    return map;
  }
}