第一步：连接数据库

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import  java.sql.Connection;
import  java.sql.DriverManager;
import  java.sql.ResultSet;
import  java.sql.SQLException;
import  java.sql.Statement;
import  javax.swing.JOptionPane;
public  class  DBConnection {
private  static  final  String DBDRIVER =  "com.mysql.jdbc.Driver" ;                  //驱动类类名
private  static  final  String DBURL =  "jdbc:mysql://localhost:3306/ibatis" ;       //连接URL
private  static  final  String DBUSER =  "root" ;                                     //数据库用户名
private  static  final  String DBPASSWORD =  "admin" ;                                //数据库密码
static {                                                                          //将加载驱动放到静态块中
try  {
Class.forName(DBDRIVER);                                                 //加载驱动
}  catch  (ClassNotFoundException e1) {                                        //发生加载驱动异常
JOptionPane.showMessageDialog( null , "加载驱动失败!!!" , "提示信息" ,
JOptionPane.INFORMATION_MESSAGE);                                //提示加载驱动失败
}
}
public  static  Connection getConnection() {
Connection conn =  null ;                                                      //建立Connection接口引用
try  {
conn = DriverManager.getConnection(DBURL, DBUSER, DBPASSWORD);           //建立连接
}  catch  (SQLException e) {                                                   // 发生连接异常
JOptionPane.showMessageDialog( null , "连接MySQL连接失败！！！" , "提示信息" ,
JOptionPane.INFORMATION_MESSAGE);                                //提示连接MySQL连接失败
}
return  conn;
}
public  static  void  close(Connection conn) {
if  (conn !=  null ) {                                                          //判断Connection对象是否为空
try  {
conn.close();                                                        // 关闭连接数据库资源
}  catch  (SQLException e){                                                //判断关闭Connection对象时是否发生异常
System.out.println( "关闭数据库连接发生异常" );
}
}
}
public  static  void  close(Statement stmt) {
if  (stmt !=  null ){                                                           //判断Statement对象是否为空
try  {
stmt.close();                                                        //关闭操作数据库资源
}  catch  (SQLException e){                                                //判断关闭Statement对象时是否发生异常
JOptionPane.showMessageDialog( null , "关闭数据库操作资源发生异常！！！" , "提示信息" ,
JOptionPane.INFORMATION_MESSAGE);                            //提示关闭数据库操作资源发生异常
}
}
}
public  static  void  close(ResultSet rs) {
if  (rs !=  null ) {                                                            //判断结果集是否为空
try  {
rs.close();                                                          //关闭结果集
}  catch  (SQLException e){                                                //判断结果集是否发生异常
JOptionPane.showMessageDialog( null , "关闭结果集发生异常！！！" , "提示信息" ,
JOptionPane.INFORMATION_MESSAGE);                            //提示关闭结果集发生异常
}
}
}
}

第二步：执行转换：

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import  java.io.File;
import  java.io.PrintWriter;
import  java.sql.Connection;
import  java.sql.DatabaseMetaData;
import  java.sql.PreparedStatement;
import  java.sql.ResultSet;
import  java.sql.ResultSetMetaData;
import  java.sql.Types;
import  org.apache.commons.dbutils.DbUtils;
public  class  BuildDTO {
public  void  build(String tableName, String packageName, String className) {
Connection conn =  null ;
PreparedStatement pment =  null ;
ResultSet rs =  null ;
PrintWriter pw =  null ;
String pack = packageName.replace( "." ,  "/" );
// 包名
System.out.println( "src/"  + pack +  "/"  + className +  ".java" );
try  {
pw =  new  PrintWriter( new  File( "src/"  + pack +  "/"  + className
+  ".java" ));
pw.println( "package "  + packageName +  ";\n\n" );
pw.println( "" );
pw.println( "public class "  + className +  " \n{\t" );
// 创建连接
conn = DBConnection.getConnection();
// 构建预处理器
pment = conn.prepareStatement( "select * from "  + tableName
+  " where 1 = 2;" );
rs = pment.executeQuery();
ResultSetMetaData metaData = rs.getMetaData();
// 获取表单的列数
int  colum = metaData.getColumnCount();
for  ( int  i =  1 ; i <= colum; i++) {
String pStr =  "" ;  // setXxxx
String typeStr =  "" ;  // 类型
// 获取列名
String columName = metaData.getColumnName(i);
// 获取每一列的数据类型
int  type = metaData.getColumnType(i);
// System.out.println(i+"---"+type);
// 判断
typeStr = type(type);
// 组装 private 的语句
pStr +=  "private "  + typeStr +  " "  + columName +  ";" ;
// 输出 private 的字段
pw.println( "\t"  + pStr +  "" );
}
String constructStr =  "" ;  // 构造
// 组装空参构造
constructStr +=  "public "  + className +  "()\n\t{\n\n\t}" ;
// 输出空参构造
pw.println( "\n\t"  + constructStr +  "\n" );
for  ( int  i =  1 ; i <= colum; i++) {
String getStr =  "" ;
String setStr =  "" ;
String typeStr =  "" ;
// 获取列名
String columName = metaData.getColumnName(i);
// 获取每一列的数据类型
int  type = metaData.getColumnType(i);
// 判断
typeStr = type(type);
// 组装 set 的语句
setStr +=  "public void set"
+ columName.substring( 0 ,  1 ).toUpperCase() +  ""
+ columName.substring( 1 ) +  "("  + typeStr +  " "
+ columName +  ")\n\t{\n" ;
setStr +=  "\t\tthis."  + columName +  " = "  + columName
+  ";\n\t}" ;
// 组装get语句
getStr +=  "public "  + typeStr +  " get"
+ columName.substring( 0 ,  1 ).toUpperCase() +  ""
+ columName.substring( 1 ) +  "()\n\t{\n\t" ;
getStr +=  "\treturn this."  + columName +  ";\n\t}" ;
// 输出 set
pw.println( "\t"  + setStr);
// 输出 get
pw.println( "\t"  + getStr);
}
pw.println( "}" );
// 缓冲
pw.flush();
pw.close();
}  catch  (Exception e) {
e.printStackTrace();
}  finally  {
// 关闭连接
DbUtils.closeQuietly(conn, pment, rs);
}
}
public  String type( int  type) {
String typeStr =  null ;
if  (Types.INTEGER == type) {
typeStr =  "Integer" ;
}  else  if  (Types.VARCHAR == type) {
typeStr =  "String" ;
}  else  if  (Types.CHAR == type) {
typeStr =  "CHAR" ;
}  else  if  (Types.TIMESTAMP == type) {
typeStr =  "Date" ;
}  else  if  (Types.INTEGER == type) {
typeStr =  "Integer" ;
}  else  if  (Types.LONGVARCHAR == type) {
typeStr =  "String" ;
}
return  typeStr;
}
//获取数据库中的所有表
public  void  getTableNameByCon(Connection con) {
try  {
DatabaseMetaData meta = con.getMetaData();
ResultSet rs = meta.getTables( null ,  null ,  null ,
new  String[] {  "TABLE"  });
while  (rs.next()) {
System.out.println( "表名："  + rs.getString( 3 ));
System.out.println( "表所属用户名："  + rs.getString( 2 ));
System.out.println( "------------------------------" );
}
con.close();
}  catch  (Exception e) {
try  {
con.close();
}  catch  (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public  static  void  main(String[] args) {
BuildDTO dto =  new  BuildDTO();
dto.build( "User" ,  "com.mzsx.sql2bean" ,  "User" );
dto.getTableNameByCon(DBConnection.getConnection());
}
}