java代码生成器（Freemaker）

package com.platform.tool.db; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.sql.Statement; import java.sql.Timestamp; import java.sql.Types; import java.util.ArrayList; import java.util.List; import com.platform.model.FieldBean; public class DbServiceImpl implements DbService { Connection conn = null; Statement st = null; ResultSet rs = null; PreparedStatement pst = null; String sqlstr = null; /**根据表名获取所有的列信息 * @param tableName * @return */ public List<FieldBean> getAllColums(String tableName){ ArrayList<FieldBean> returnList = new ArrayList<FieldBean>(); DbConn dbConn = new DbConn(); try { this.conn = dbConn.getConnection(); this.sqlstr = "select * from " + tableName; this.st = conn.createStatement(); this.rs = this.st.executeQuery(sqlstr); ResultSetMetaData resultSetMetaData = rs.getMetaData(); for(int i=1;i<=resultSetMetaData.getColumnCount();i++){ String columName = resultSetMetaData.getColumnName(i); String proName = convertField(columName); String dataType = getTypeName(resultSetMetaData.getColumnType(i)); FieldBean fieldBean = new FieldBean(); fieldBean.setFieldName(columName.toLowerCase()); fieldBean.setProName(proName); fieldBean.setProType(dataType); returnList.add(fieldBean); } } catch (SQLException e) { e.printStackTrace(); } finally{ dbConn.closeALL(conn, st, rs, pst); } return returnList; } /** * 把数据库中的字段转换为变量类型 * 如（user_id ----> userId） * @param field * @return */ public String convertField(String field) { //分隔符 char separator = '_'; //转化为小写 String variable = field.toLowerCase(); if (variable.indexOf(separator)>-1) { char[] varArray = variable.toCharArray(); for(int i=0;i<varArray.length;i++){ if (varArray[i]==separator&&i<varArray.length-1) { varArray[i+1]=Character.toUpperCase(varArray[i+1]); } } variable = new String(varArray).replaceAll("_", ""); } return variable; } /**获取字符串型的类型名 * @param type * @return */ private String getTypeName(int type){ String typeName = String.class.getSimpleName(); switch (type) { case Types.VARCHAR: case Types.BLOB: break; case Types.INTEGER: case Types.SMALLINT: case Types.NUMERIC: typeName=Integer.class.getSimpleName(); break; case Types.DATE: case Types.TIMESTAMP: typeName=Timestamp.class.getSimpleName(); break; case Types.BOOLEAN: typeName=Boolean.class.getSimpleName(); break; case Types.FLOAT: typeName=Float.class.getSimpleName(); break; default: break; } return typeName; } }