根据库表结构自动生成java实体类(生成规范的变量及get/set方法).

/**
* java根据库表结构自动生成java实体,在网上找了相关资料，已经有很多大侠实现了这功能。
* 但是并没有一个使我自己满意的，要么生成的变量不规范，要么就是格式很乱。
* 所以我参照网上一些已有的方法，自己动手改进了下，实现了可以生成规范的字段名及
* get/set方法，只不过这里有个前提，就是在新建表字段时如果字段名较长，那么必须遵守用"_"隔开。
* 其实只有这样才能规范，毕竟电脑也不是万能的，不可能根据你想要的格式自动生成规范的变量名及get/set方法。
*/

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Date;

public class GenEntityOracle {

private String packageOutPath = "com.user.entity";//指定实体生成所在包的路径
private String authorName = "张三";//作者名字
private String tablename = "RECORD";//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:oracle:thin:@192.168.1.113:1521:eport";
private static final String NAME = "test";
private static final String PASS = "test";
private static final String DRIVER ="oracle.jdbc.driver.OracleDriver";

/*
* 构造函数
*/
public GenEntityOracle(){
//创建连接
Connection con;
//查要生成实体类的表
String sql = "select * from " + tablename;
Statement pStemt = null;
try {
try {
Class.forName(DRIVER);
} catch (ClassNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
con = DriverManager.getConnection(URL,NAME,PASS);
pStemt = (Statement) con.createStatement();
ResultSet rs = pStemt.executeQuery(sql);
ResultSetMetaData rsmd = rs.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("date") || colTypes[i].equalsIgnoreCase("timestamp")){
f_util = true;
}
if(colTypes[i].equalsIgnoreCase("blob") || colTypes[i].equalsIgnoreCase("char")){
f_sql = true;
}
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}

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

try {
File directory = new File("");
//System.out.println("绝对路径："+directory.getAbsolutePath());
//System.out.println("相对路径："+directory.getCanonicalPath());
String path=this.getClass().getResource("").getPath();

System.out.println(path);
//System.out.println("src/?/"+path.substring(path.lastIndexOf("/com/", path.length())) );
//    String outputPath = directory.getAbsolutePath()+ "/src/"+path.substring(path.lastIndexOf("/com/", path.length()), path.length()) + initcap(tablename) + ".java";
String outputPath = directory.getAbsolutePath()+ "/src/"+this.packageOutPath.replace(".", "/")+"/"+initcap(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{
//   try {
//    con.close();
//   } catch (SQLException e) {
//    // TODO Auto-generated catch block
//    e.printStackTrace();
//   }
}
}

/**
* 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");
//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("\r\n");
//注释部分
sb.append("   /**\r\n");
sb.append("    * "+initcap(tablename)+" 实体类\r\n");
sb.append("    * "+new Date()+" "+this.authorName+"\r\n");
sb.append("    */ \r\n");
//实体部分
sb.append("\r\n\r\npublic class " + initcap(tablename) + "{\r\n");
processAllAttrs(sb);//属性
processAllMethod(sb);//get set方法
sb.append("}\r\n");

//System.out.println("999999 = " +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++) {
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + defineVar(colnames[i]) + ";\r\n");
}

}

/**
* 功能：生成所有方法
* @param sb
*/
private void processAllMethod(StringBuffer sb) {

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

}

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

char[] ch = str.toLowerCase().toCharArray();
System.out.println("6666 str = "+str.toString());
if(ch[0] >= 'a' && ch[0] <= 'z'){
ch[0] = (char)(ch[0] - 32);
}

return new String(ch);
}

/**
* 用于生成get/set方法时
* 功能：先将变量字母全变为小写，将第一个字母变为大写，将紧跟“_”后面一个字母大写，并去掉“_”.
* @param str
* @return
*/
private String transVar(String str){
System.out.println("111"+str);
int index = 0;
if(str.indexOf("_")!=-1){
index = str.indexOf("_");
str = str.replace("_", "");
}
System.out.println("222"+str);
char[] ch = str.toLowerCase().toCharArray();
if(ch[0] >= 'a' && ch[0] <= 'z'){
ch[0] = (char)(ch[0] - 32);
if(index!=0){
ch[index] = (char)(ch[index] - 32);
}
}
str =  new String(ch);
System.out.println("333"+str);
return str;
}

/**
* 用于定义变量名
* 功能：先将变量字母全变为小写，将紧跟“_”后面一个字母大写，并去掉“_”.
* @param str
* @return
*/
private String defineVar(String str){
int index = 0;
if(str.indexOf("_")!=-1){
index = str.indexOf("_");
str = str.replace("_", "");
}
char[] ch = str.toLowerCase().toCharArray();
if(ch[0] >= 'a' && ch[0] <= 'z'&&index!=0){
ch[index] = (char)(ch[index] - 32);
}
str =  new String(ch);
return str;
}

/**
* 功能：获得列的数据类型
* @param sqlType
* @return
*/
private String sqlType2JavaType(String sqlType) {

if(sqlType.equalsIgnoreCase("binary_double")){
return "double";
}else if(sqlType.equalsIgnoreCase("binary_float")){
return "float";
}else if(sqlType.equalsIgnoreCase("blob")){
return "byte[]";
}else if(sqlType.equalsIgnoreCase("blob")){
return "byte[]";
}else if(sqlType.equalsIgnoreCase("char") || sqlType.equalsIgnoreCase("nvarchar2")
|| sqlType.equalsIgnoreCase("varchar2")){
return "String";
}else if(sqlType.equalsIgnoreCase("date") || sqlType.equalsIgnoreCase("timestamp")
|| sqlType.equalsIgnoreCase("timestamp with local time zone")
|| sqlType.equalsIgnoreCase("timestamp with time zone")){
return "Date";
}else if(sqlType.equalsIgnoreCase("number")){
return "Long";
}

return "String";
}

/**
* 出口
* TODO
* @param args
*/
public static void main(String[] args) {

new GenEntityOracle();

}

}