JAVA通过实体生成数据库表

package com.tangwt.util; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.lang.annotation.Annotation; import java.lang.reflect.Field; import java.util.Properties; import com.tangwt.bean.MyTag; public class ColumUtil { private static Properties pro = new Properties(); public static String getColumName(String colum) { StringBuffer ff = new StringBuffer(""); for (int i = 0; i < colum.length(); i++) { char c = colum.charAt(i); if (!Character.isLowerCase(c)) { ff.append("_").append(String.valueOf(c).toLowerCase()); } else { ff.append(c); } } return ff.toString(); } public static String getTableName(String tableName) { if (tableName.contains(".")) { String[] tables = tableName.split("\\."); tableName = tables[tables.length - 1]; } StringBuffer ff = new StringBuffer(""); for (int i = 0; i < tableName.length(); i++) { char c = tableName.charAt(i); if (!Character.isLowerCase(c)) { if (i == 0) ff.append(String.valueOf(c).toLowerCase()); else ff.append("_").append(String.valueOf(c).toLowerCase()); } else { ff.append(c); } } return ff.toString(); } public static String getCreateSql(Object obj) { Class<?> clz = obj.getClass(); Field[] fields = clz.getDeclaredFields(); StringBuffer sql = new StringBuffer("CREATE TABLE "); String tableName = getTableName(clz.getName()); sql.append(tableName).append(" ("); for (int i = 0; i < fields.length; i++) { Field field = fields[i]; Annotation[] aArray = field.getDeclaredAnnotations(); boolean isPK = false; String length = "0"; if (aArray != null) { for (Annotation an : aArray) { MyTag tag = (MyTag) an; isPK = tag.isPK(); length = tag.length(); } } String f = field.getName(); String colum = ColumUtil.getColumName(f); try { InputStream is = ColumUtil.class.getClass().getResourceAsStream("/type.properties"); pro.load(is); String fileType = field.getType().toString(); String[] fileTypes = fileType.split("\\."); fileType = (String) pro.get(fileTypes[fileTypes.length - 1]); //System.out.println(fileType); sql.append(colum).append(" ").append(fileType); if(!(length.equals("0"))){ sql.append("(").append(length).append(")"); } if(isPK){ sql.append(" not null primary key "); } if (i == fields.length - 1) sql.append(" )"); else sql.append(" ,"); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } System.err.println(sql.toString()); return sql.toString(); } }