如何将一个数据库中的表，转化为一个javabean对象

package com.coffee.common;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.Vector;

public class reflectBean {
private Connection connection;
private PreparedStatement UserQuery;
/*mysql url的连接字符串*/
private static String url = "jdbc:mysql://127.0.0.1:3306/test1?useUnicode=true&characterEncoding=utf-8&useOldAliasMetadataBehavior=true";
//账号
private static String user = "root";
//密码
private static String password = "123";
private Vector<String> vector = new Vector<String>();
//mysql jdbc的java包驱动字符串
private String driverClassName = "com.mysql.jdbc.Driver";
//数据库中的表名
String table = "e_task_result";
//数据库的列名称
private String[] colnames; // 列名数组
//列名类型数组
private String[] colTypes;
public reflectBean(){
try {//驱动注册
Class.forName(driverClassName);
if (connection == null || connection.isClosed())
//获得链接
connection = DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
System.out.println("Oh,not");
} catch (SQLException e) {
e.printStackTrace();
System.out.println("Oh,not");
}
}

public Connection getConnection() {
return connection;
}
public void setConnection(Connection connection) {
this.connection = connection;
}

public void doAction(){
String sql = "select * from "+table;
try {
PreparedStatement statement = connection.prepareStatement(sql);
//获取数据库的元数据
ResultSetMetaData metadata = statement.getMetaData();
//数据库的字段个数
int len = metadata.getColumnCount();
//字段名称
colnames = new String[len+1];
//字段类型 --->已经转化为java中的类名称了
colTypes = new String[len+1];
for(int i= 1;i<=len;i++){
//System.out.println(metadata.getColumnName(i)+":"+metadata.getColumnTypeName(i)+":"+sqlType2JavaType(metadata.getColumnTypeName(i).toLowerCase())+":"+metadata.getColumnDisplaySize(i));
//metadata.getColumnDisplaySize(i);
colnames[i] = metadata.getColumnName(i); //获取字段名称
colTypes[i] = sqlType2JavaType(metadata.getColumnTypeName(i)); //获取字段类型
}
} catch (SQLException e) {
e.printStackTrace();
}
}
/*
* mysql的字段类型转化为java的类型*/
private String sqlType2JavaType(String sqlType) {

if(sqlType.equalsIgnoreCase("bit")){
return "boolean";
}else if(sqlType.equalsIgnoreCase("tinyint")){
return "byte";
}else if(sqlType.equalsIgnoreCase("smallint")){
return "short";
}else if(sqlType.equalsIgnoreCase("int")){
return "int";
}else if(sqlType.equalsIgnoreCase("bigint")){
return "long";
}else if(sqlType.equalsIgnoreCase("float")){
return "float";
}else if(sqlType.equalsIgnoreCase("decimal") || sqlType.equalsIgnoreCase("numeric")
|| sqlType.equalsIgnoreCase("real") || sqlType.equalsIgnoreCase("money")
|| sqlType.equalsIgnoreCase("smallmoney")){
return "double";
}else if(sqlType.equalsIgnoreCase("varchar") || sqlType.equalsIgnoreCase("char")
|| sqlType.equalsIgnoreCase("nvarchar") || sqlType.equalsIgnoreCase("nchar")
|| sqlType.equalsIgnoreCase("text")){
return "String";
}else if(sqlType.equalsIgnoreCase("datetime") ||sqlType.equalsIgnoreCase("date")){
return "Date";
}else if(sqlType.equalsIgnoreCase("image")){
return "Blod";
}

return null;
}
/*获取整个类的字符串并且输出为java文件
* */
public  StringBuffer getClassStr(){
//输出的类字符串
StringBuffer str = new StringBuffer("");
//获取表类型和表名的字段名
this.doAction();
//校验
if(null == colnames && null == colTypes) return null;
//拼接
str.append("public class "+table+" {\r\n");
//拼接属性
for(int index=1; index < colnames.length ; index++){
str.append(getAttrbuteString(colnames[index],colTypes[index]));
}
//拼接get，Set方法
for(int index=1; index < colnames.length ; index++){
str.append(getGetMethodString(colnames[index],colTypes[index]));
str.append(getSetMethodString(colnames[index],colTypes[index]));
}
str.append("}\r\n");
//输出到文件中
File file = new File(table+".java");
BufferedWriter write = null;

try {
write = new BufferedWriter(new FileWriter(file));
write.write(str.toString());
write.close();
} catch (IOException e) {

e.printStackTrace();
if (write != null)
try {
write.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
return str;
}
/*
* 获取字段字符串*/
public StringBuffer getAttrbuteString(String name, String type) {
if(!check(name,type)) {
System.out.println("类中有属性或者类型为空");
return null;
};
String format = String.format("    private %s %s;\n\r", new String[]{type,name});
return new StringBuffer(format);
}
/*
* 校验name和type是否合法*/
public boolean check(String name, String type) {
if("".equals(name) || name == null || name.trim().length() ==0){
return false;
}
if("".equals(type) || type == null || type.trim().length() ==0){
return false;
}
return true;

}
/*
* 获取get方法字符串*/
private StringBuffer getGetMethodString(String name, String type) {
if(!check(name,type)) {
System.out.println("类中有属性或者类型为空");
return null;
};
String Methodname = "get"+GetTuoFeng(name);
String format = String.format("    public %s %s(){\n\r", new Object[]{type,Methodname});
format += String.format("        return this.%s;\r\n", new Object[]{name});
format += "    }\r\n";
return new StringBuffer(format);
}
//将名称首字符大写
private String GetTuoFeng(String name) {
name = name.trim();
if(name.length() > 1){
name = name.substring(0, 1).toUpperCase()+name.substring(1);
}else
{
name = name.toUpperCase();
}
return name;
}
/*
* 获取字段的get方法字符串*/
private Object getSetMethodString(String name, String type) {
if(!check(name,type)) {
System.out.println("类中有属性或者类型为空");
return null;
};
String Methodname = "set"+GetTuoFeng(name);
String format = String.format("    public void %s(%s %s){\n\r", new Object[]{Methodname,type,name});
format += String.format("        this.%s = %s;\r\n", new Object[]{name,name});
format += "    }\r\n";
return new StringBuffer(format);
}

public static void main(String[] args) {
reflectBean bean = new reflectBean();
System.err.println(bean.getClassStr());
}

}