java自动生成entity文件
网上关于自动生成entity文件的代码很多,看了很多代码后,在先辈们的基础上再完善一些功能(指定多个表,全部表).
为了使用方便所以把两个类写在一个java文件中,所以大家可以直接拿这个java文件,修改下配置后就可以使用了,传送门
1.把字段抽象为一个类
/** * 字段信息表 */ class FieldMeta { private String fieldName; //字段名 private String fieldDataType; //字段类型 private int fieldLength; //字段长度 private String fieldComment; //字段备注 public String getFieldName() { return fieldName; } public void setFieldName(String fieldName) { this.fieldName = fieldName; } public String getFieldDataType() { if(fieldDataType.equalsIgnoreCase("bit")){ return "boolean"; }else if(fieldDataType.equalsIgnoreCase("tinyint")){ return "byte"; }else if(fieldDataType.equalsIgnoreCase("smallint")){ return "short"; }else if(fieldDataType.equalsIgnoreCase("int")){ return "int"; }else if(fieldDataType.equalsIgnoreCase("bigint")){ return "long"; }else if(fieldDataType.equalsIgnoreCase("float")){ return "float"; }else if(fieldDataType.equalsIgnoreCase("decimal") || fieldDataType.equalsIgnoreCase("numeric") || fieldDataType.equalsIgnoreCase("real") || fieldDataType.equalsIgnoreCase("money") || fieldDataType.equalsIgnoreCase("smallmoney")){ return "double"; }else if(fieldDataType.equalsIgnoreCase("varchar") || fieldDataType.equalsIgnoreCase("char") || fieldDataType.equalsIgnoreCase("nvarchar") || fieldDataType.equalsIgnoreCase("nchar") || fieldDataType.equalsIgnoreCase("text") || fieldDataType.equalsIgnoreCase("LONGTEXT")){ return "String"; }else if(fieldDataType.equalsIgnoreCase("datetime")){ return "Date"; }else if(fieldDataType.equalsIgnoreCase("image")){ return "Blod"; } return fieldDataType; } public void setFieldDataType(String fieldDataType) { if(fieldDataType.equalsIgnoreCase("bit")){ this.fieldDataType = "boolean"; }else if(fieldDataType.equalsIgnoreCase("tinyint")){ this.fieldDataType = "byte"; }else if(fieldDataType.equalsIgnoreCase("smallint")){ this.fieldDataType = "short"; }else if(fieldDataType.equalsIgnoreCase("int")){ this.fieldDataType = "int"; }else if(fieldDataType.equalsIgnoreCase("bigint")){ this.fieldDataType = "long"; }else if(fieldDataType.equalsIgnoreCase("float")){ this.fieldDataType = "float"; }else if(fieldDataType.equalsIgnoreCase("decimal") || fieldDataType.equalsIgnoreCase("numeric") || fieldDataType.equalsIgnoreCase("real") || fieldDataType.equalsIgnoreCase("money") || fieldDataType.equalsIgnoreCase("smallmoney")){ this.fieldDataType = "double"; }else if(fieldDataType.equalsIgnoreCase("varchar") || fieldDataType.equalsIgnoreCase("char") || fieldDataType.equalsIgnoreCase("nvarchar") || fieldDataType.equalsIgnoreCase("nchar") || fieldDataType.equalsIgnoreCase("text") || fieldDataType.equalsIgnoreCase("LONGTEXT") || fieldDataType.equalsIgnoreCase("TIMESTAMP")){ this.fieldDataType = "String"; }else if(fieldDataType.equalsIgnoreCase("datetime") || fieldDataType.equalsIgnoreCase("date")){ this.fieldDataType = "Date"; }else if(fieldDataType.equalsIgnoreCase("image")){ this.fieldDataType = "Blod"; }else { this.fieldDataType = fieldDataType; } } public int getFieldLength() { return fieldLength; } public void setFieldLength(int fieldLength) { this.fieldLength = fieldLength; } public String getFieldComment() { return fieldComment; } public void setFieldComment(String fieldComment) { this.fieldComment = fieldComment; } }
2.通用方法,jdbc的创建与关闭,首字母大写方法.
/** * 功能:将输入字符串的首字母改成大写 * @param str * @return */ private String upFirstChar(String str) { if (str!=null&&str.length()>0) { char[] ch = str.toCharArray(); if(ch[0] >= 'a' && ch[0] <= 'z'){ ch[0] = (char)(ch[0] - 32); } return new String(ch); } return null; } /** * 获取jdbc连接 */ private Connection getJdbcCon(){ try { Class.forName(DRIVER); return DriverManager.getConnection(URL,NAME,PASS); } catch (SQLException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } return null; } /** * 关闭所有资源 */ private void closeAll(ResultSet resultSet,PreparedStatement preparedStatement,Connection connnection,CallableStatement callableStatement) { // 关闭结果集对象 if (resultSet != null) { try { resultSet.close(); } catch (SQLException e) { System.out.println(e.getMessage()); } } // 关闭PreparedStatement对象 if (preparedStatement != null) { try { preparedStatement.close(); } catch (SQLException e) { System.out.println(e.getMessage()); } } // 关闭CallableStatement 对象 if (callableStatement != null) { try { callableStatement.close(); } catch (SQLException e) { System.out.println(e.getMessage()); } } // 关闭Connection 对象 if (connnection != null) { try { connnection.close(); } catch (SQLException e) { System.out.println(e.getMessage()); } } }
3.生成类,生成字段,生成方法
/** * 生成类主题框架 */ public String genFrame(List<FieldMeta> fmls,String tableName){ StringBuilder sb = new StringBuilder(); //package空间 sb.append("package "+this.packagePath+";\r\n\r\n"); // 判断是否导入工具包 if (f_util) { sb.append("import java.util.Date;\r\n"); } if (f_sql) { sb.append("import java.sql.*;\r\n"); } // 注释部分 sb.append("/**\r\n"); sb.append(" * 名 称:" + tableName + "\r\n"); sb.append(" * 描 述:\r\n"); sb.append(" * 作 者:" + this.authorName + "\r\n"); sb.append(" * 时 间:" + new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(new Date()) + "\r\n"); sb.append(" * --------------------------------------------------" + "\r\n"); sb.append(" * 修改历史" + "\r\n"); sb.append(" * 序号 日期 修改人 修改原因 "+ "\r\n"); sb.append(" * 1" + "\r\n"); sb.append(" * **************************************************" + "\r\n"); sb.append(" */\r\n"); // 实体部分 sb.append("public class " + upFirstChar(tableName) + "{\r\n"); //字段部分 genAttrs(sb, fmls); //方法部分 genMethods(sb, fmls); sb.append("}\r\n"); return new String(sb); } /** * 功能:生成所有属性 */ private void genAttrs(StringBuilder sb,List<FieldMeta> fmls) { for (int i = 0; i < fmls.size(); i++) { sb.append("\t"); sb.append("private " + fmls.get(i).getFieldDataType() + " " + fmls.get(i).getFieldName() + ";"); sb.append("\t/*"+fmls.get(i).getFieldComment()+"\tlen: "+fmls.get(i).getFieldLength()+"*/\r\n"); } sb.append("\r\n"); } /** * 功能:生成所有方法 */ private void genMethods(StringBuilder sb,List<FieldMeta> fmls){ for (int i = 0; i < fmls.size(); i++) { sb.append("\tpublic void set"+upFirstChar(fmls.get(i).getFieldName())+"("+fmls.get(i).getFieldDataType()+" "+fmls.get(i).getFieldName()+"){\r\n"); sb.append("\t\tthis."+fmls.get(i).getFieldName()+"="+fmls.get(i).getFieldName()+";\r\n"); sb.append("\t}\r\n"); sb.append("\tpublic "+fmls.get(i).getFieldDataType()+" get"+upFirstChar(fmls.get(i).getFieldName())+"(){\r\n"); sb.append("\t\treturn "+fmls.get(i).getFieldName()+";\r\n"); sb.append("\t}\r\n"); sb.append("\r\n"); } sb.append(""); }
4.其他方法,写入文件方法,获取所有表名方法
/** * 写入文件 */ private void wirteToFile(String content,String packagePath,String tableName){ PrintWriter pw = null; BufferedWriter bw = null; File dir = new File(""); //根据空文件获取项目路径 //entity文件父文件夹全路径 String dirpath = dir.getAbsolutePath() + "\\src\\"+packagePath.replace(".", "\\"); File parentDir = new File(dirpath); if (!parentDir.exists()) { //判断是否存在该路径 parentDir.mkdirs(); //不存在则创建 } String filePath = dirpath+"\\"+upFirstChar(tableName)+".java"; //java文件路径 File file = new File(filePath); try { if (!file.exists()) { //判断是否存在java文件 file.createNewFile(); //不存在则创建 }else { System.out.print("表 "+tableName+" 的entity实体已存在于:"); } pw = new PrintWriter(new OutputStreamWriter(new FileOutputStream(filePath), "utf-8")); //OutputStreamWriter为了解决乱码 bw = new BufferedWriter(pw); bw.write(content); } catch (IOException e) { e.printStackTrace(); } finally{ try { if (bw!=null) { bw.close(); } if (pw!=null) { pw.close(); } } catch (IOException e) { e.printStackTrace(); } } System.out.println(filePath); } //获取所有表名 private String[] getAllTables(){ List<String> stringList = new ArrayList<String>(); Connection con = null; PreparedStatement ps = null; ResultSet rs =null; con = getJdbcCon(); String sql = "show tables"; try { ps = con.prepareStatement(sql); rs = ps.executeQuery(); while (rs.next()) { stringList.add(rs.getString(1)); } } catch (SQLException e) { e.printStackTrace(); } finally{ closeAll(rs, ps, con, null); } return stringList.toArray(new String[stringList.size()]); }
5.执行
private String packagePath = "com.qy.entity"; //指定实体生成所在包的路径 //表名以","分隔;若为"*"则生成所有表的entity文件 private String tableNames = "*"; private String authorName = "邱宇"; //作者名字 private static final String DRIVER = "com.mysql.jdbc.Driver"; private static final String URL = "jdbc:mysql://localhost:3306/protocol"; private static final String NAME = "qy"; private static final String PASS = "199526"; 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.* public static void main(String[] args) { new CreateEntity(); } public CreateEntity(){ String[] tables = null; if (this.tableNames=="*") { tables = getAllTables(); }else { tables = this.tableNames.split(","); } for (int i = 0; i < tables.length; i++) { new CreateEntity(tables[i]); f_util = false; f_sql = false; } } public CreateEntity(String tableName){ Connection con = null; PreparedStatement ps = null; ResultSet rs = null; DatabaseMetaData dbmd = null; //ResultSetMetaData rsmd= null; List<FieldMeta> fmls = new ArrayList<FieldMeta>(); String sql= "select * from "+tableName; try { con=getJdbcCon(); dbmd = con.getMetaData(); rs = dbmd.getColumns(con.getCatalog(), null, tableName, null); while (rs.next()) { FieldMeta fm = new FieldMeta(); fm.setFieldName(rs.getString("COLUMN_NAME")); if (rs.getString("TYPE_NAME").equalsIgnoreCase("datetime") || rs.getString("TYPE_NAME").equalsIgnoreCase("date")) { f_util = true; } if (rs.getString("TYPE_NAME").equalsIgnoreCase("image") || rs.getString("TYPE_NAME").equalsIgnoreCase("text")) { f_sql = true; } fm.setFieldDataType(rs.getString("TYPE_NAME")); fm.setFieldLength(Integer.parseInt(rs.getString("COLUMN_SIZE"))); fm.setFieldComment(rs.getString("REMARKS").replace("\r\n", " ")); //注释中的换行改为空格 fmls.add(fm); } /* 从resultSet读取的ResultSetMetaData没有注释等详细信息 ps = con.prepareStatement(sql); rs = ps.executeQuery(); rsmd = rs.getMetaData(); for (int i = 0; i < rsmd.getColumnCount(); i++) { FieldMeta fm = new FieldMeta(); fm.setFieldName(rsmd.getColumnName(i+1)); if (rsmd.getColumnTypeName(i+1).equalsIgnoreCase("datetime")) { f_util = true; } if (rsmd.getColumnTypeName(i+1).equalsIgnoreCase("image") || rsmd.getColumnTypeName(i+1).equalsIgnoreCase("text")) { f_sql = true; } fm.setFieldDataType(rsmd.getColumnTypeName(i+1)); fm.setFieldLength(rsmd.getColumnDisplaySize(i+1)); //fm.setFieldComment(fieldComment); fmls.add(fm); }*/ } catch (SQLException e) { e.printStackTrace(); } finally{ if (con!=null) { closeAll(rs, ps, con, null); } } //生成内容 String content = genFrame(fmls,tableName); //System.out.println(content); //写入到文件 wirteToFile(content,this.packagePath,tableName); }
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