Java实现自动生成Mysql数据库表实体类

/**
* @(#) GenEntityMysql.java	2017-2-8 下午3:06:18
*
* Copyright (c) 2014-2015 Diyvc, Inc.
* 103 Sports Road, Victoria Plaza tower 1104, Tianhe District Guangzhou City, China.
* All rights reserved.
*
*/
package com.frend.controller;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class Mysql2EntityGenerator {

private String packageOutPath = "com.test.domain";//指定实体生成所在包的路径
private String authorName = "frend";//作者名字
private String tablename = "";//表名
private String[] colnames; // 列名数组
private String[] colTypes; //列名类型数组
private int[] colSizes; //列名大小数组
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.*

//数据库连接
private static final String URL ="jdbc:mysql://127.0.0.1:3306/sqlname";
private static final String NAME = "root";
private static final String PASSWORD = "root";
private static final String DRIVER ="com.mysql.jdbc.Driver";

/*
* 构造函数
*/
public Mysql2EntityGenerator(Connection con,String tableName){
this.tablename = tableName;
//创建连接
//查要生成实体类的表
String sql = "select * from " + tablename;
PreparedStatement pStemt = null;
try {

pStemt = con.prepareStatement(sql);
ResultSetMetaData rsmd = pStemt.getMetaData();
int size = rsmd.getColumnCount();	//统计列
colnames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
for (int i = 0; i < size; i++) {
colnames[i] = rsmd.getColumnName(i + 1);
colTypes[i] = rsmd.getColumnTypeName(i + 1);

if(colTypes[i].equalsIgnoreCase("datetime")){
f_util = true;
}
if(colTypes[i].equalsIgnoreCase("image") || colTypes[i].equalsIgnoreCase("text")){
f_sql = true;
}
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}

String content = parse(colnames,colTypes,colSizes);

try {
File directory = new File("");
String outputPath = directory.getAbsolutePath()+ "/src/"+this.packageOutPath.replace(".", "/")+"/"+parseName(tablename) + ".java";
FileWriter fw = new FileWriter(outputPath);
PrintWriter pw = new PrintWriter(fw);
pw.println(content);
pw.flush();
pw.close();
} catch (IOException e) {
e.printStackTrace();
}

} catch (SQLException e) {
e.printStackTrace();
} finally{
}
}

/**
* 功能：生成实体类主体代码
* @param colnames
* @param colTypes
* @param colSizes
* @return
*/
private String parse(String[] colnames, String[] colTypes, int[] colSizes) {
StringBuffer sb = new StringBuffer();

sb.append("package " + this.packageOutPath + ";\r\n");
sb.append("\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");
}
sb.append("import javax.persistence.Column;\r\n");
sb.append("import javax.persistence.Entity;\r\n");
sb.append("import javax.persistence.GeneratedValue;\r\n");
sb.append("import javax.persistence.GenerationType;\r\n");
sb.append("import javax.persistence.Id;\r\n");
sb.append("import javax.persistence.Table;\r\n");
sb.append("import javax.persistence.Temporal;\r\n");
sb.append("import javax.persistence.TemporalType;\r\n");
sb.append("import org.springframework.format.annotation.DateTimeFormat;\r\n");

//注释部分
sb.append("   /**\r\n");
sb.append("    * "+tablename+" 实体类\r\n");
sb.append("    * "+new Date()+" "+this.authorName+"\r\n");
sb.append("    */ \r\n");
//实体部分
sb.append("@Entity\r\n");
sb.append("@Table(name = \""+tablename+"\")\r\n");
sb.append("public class " + parseName(tablename) + "{\r\n");
processAllAttrs(sb);//属性
processAllMethod(sb);//get set方法
sb.append("}\r\n");

//System.out.println(sb.toString());
return sb.toString();
}

/**
* 功能：生成所有属性
* @param sb
*/
private void processAllAttrs(StringBuffer sb) {

for (int i = 0; i < colnames.length; i++) {
String column = parseNameNotFirst(colnames[i]);
if(column.equals("fileSize")){
System.out.println("here");
}
sb.append("\r\n");
if("id".equals(column)){
sb.append("\t@Id\r\n");
sb.append("\t@GeneratedValue(strategy = GenerationType.IDENTITY)\r\n");
sb.append("\t@Column(name = \""+colnames[i]+"\", unique = true, nullable = false)\r\n");
}else{
sb.append("\t@Column(name = \""+colnames[i]+"\")\r\n");
}
if("Date".equals(sqlType2JavaType(colTypes[i]))){
sb.append("\t@DateTimeFormat(pattern = \"yyyy-MM-dd HH:mm:ss\")\r\n");
sb.append("\t@Temporal(value = TemporalType.TIMESTAMP)\r\n");
}
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + column + ";\r\n");
}

}

/**
* 功能：生成get、set方法
* @param sb
*/
private void processAllMethod(StringBuffer sb) {

for (int i = 0; i < colnames.length; i++) {
sb.append("\r\n");
sb.append("\tpublic void set" + parseName(colnames[i]) + "(" + sqlType2JavaType(colTypes[i]) + " " +
parseNameNotFirst(colnames[i]) + "){\r\n");
sb.append("\t\tthis." + parseNameNotFirst(colnames[i]) + "=" + parseNameNotFirst(colnames[i]) + ";\r\n");
sb.append("\t}\r\n");
sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get" + parseName(colnames[i]) + "(){\r\n");
sb.append("\t\treturn " + parseNameNotFirst(colnames[i]) + ";\r\n");
sb.append("\t}\r\n");
}

}

/**
* 描述：第一个首字母不大写，后面大写
* @param name
* @return
* String
*/
public String parseNameNotFirst(String name){
StringBuffer sb = new StringBuffer();
String[] array = name.split("_");
if(array.length > 0){
for (int i = 0; i < array.length; i++) {
if (i>0) {
sb.append(initcap(array[i]));
}else{
sb.append(array[i]);
}
}
}

return sb.toString();
}

/**
* 描述：全部首字母大写
* @param name
* @return
* String
*/
public String parseName(String name){
StringBuffer sb = new StringBuffer();
String[] array = name.split("_");
if(array.length > 0){
for (String string : array) {
sb.append(initcap(string));
}
}

return sb.toString();
}

/**
* 功能：将输入字符串的首字母改成大写（修改成驼峰法）
* @param str
* @return
*/
private String initcap(String str) {

char[] ch = str.toCharArray();
if(ch[0] >= 'a' && ch[0] <= 'z'){
ch[0] = (char)(ch[0] - 32);
}

return new String(ch);
}

/**
* 功能：获得列的数据类型
* @param sqlType
* @return
*/
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") || sqlType.equalsIgnoreCase("INT UNSIGNED")){
return "Integer";
}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")){
return "Date";
}else if(sqlType.equalsIgnoreCase("image")){
return "Blod";
}

return null;
}

/**
* 出口
* TODO
* @param args
*/
public static void main(String[] args) {
List<String> tableList = new ArrayList<String>();
Connection con;
try {
Class.forName(DRIVER);
con = DriverManager.getConnection(URL,NAME,PASSWORD);
DatabaseMetaData  dm = con.getMetaData();
ResultSet rs  = dm.getTables(con.getCatalog(), "root", null, new String[]{"TABLE"});
while(rs.next()) {
tableList.add(rs.getString("TABLE_NAME"));
System.out.println("得到表名："+rs.getString("TABLE_NAME"));
}
/*if (tableList!=null) {
for (String tableName : tableList) {
new GenEntityMysql(con,tableName);
}
}*/
new Mysql2EntityGenerator(con,"file_attachment_info");
} catch (ClassNotFoundException e1) {
e1.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}

}