Introduce a tool to generate code by writing JavaScript

Java Based Code Generator – jbcgen

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Short Description:

This code generator generates files from database and templates written in JavaScript. it supports db plugin, and it’s easy to extend and use. It supports mysql and db which support ado connection(under windows only) for now.

When To Use

It should be used especially when the code logic is similar, but the table is different. It will save much of your time by generating code automatically instead of copy&paste. For example, you want to write 5 files for each table, you only need to write lines of javascript code without coding the files lots of time.

Why To Use

The reason is very simple, the program is very simple and it will save much of your time.

A very simple example:

public class Base<%=getDomainByTable(sys_table_name)%>{
for(var i=0;i<sys_fields.length;i++){
    var type=getJavaBeanType(sys_fields[i].type);

for(var i=0;i<sys_fields.length;i++){
    var type=getJavaBeanType(sys_fields[i].type);

    public void set<%=formatFieldName(sys_fields[i].name)%>(<%=type%><%=sys_fields[i].name%>){


If the current table has role_id int, role_name varchar, description varchar, then the result will be:

public class BaseRole {
    private int role_id;
    private String role_name;
    private String description;

    public int getRoleId() {
        return role_id;

    public void setRoleId(int role_id) {
        this.role_id = role_id;

    public String getRoleName() {
        return role_name;

    public void setRoleName(String role_name) {
        this.role_name = role_name;

    public String getDescription() {
        return description;

    public void setDescription(String description) {
        this.description = description;

Script Tag:

  1. <$
    //Javascript code like: println(sys_fields[0].name);
  2. <$=sys_fields[0].name$>

Predefined variables:

  1. sys_table_name: current selected table name
  2. sys_fields: Array of Field object. use sys_fields.length to get the field count of current table.
  3. sys_keys: Array of Primary key column, use sys_keys.length to get the field count of current table.
  4. sys_user_name: User name used to connect to current database.
  5. sys_db_name: Database name used to connect to.
  6. sys_output: Internal use only which store the temporary generated code. User can use it too by println(sys_output).
  7. Field Object, if there’s a field: user_name varchar(100) not null default ‘user’, here’s the available fields and values:
    name: field name, String. For Example: sys_fields[i].name, example value is user_name
    type: field type, String, For Example: sys_fields[i].type, example value is varchar
    size: field length, integer, For Example: sys_fields[i].size, example value is 100
    scale: field scale, integer, For Example: sys_fields[i].scale, not available in this case
    default_value: Default value for the field, String. For Example: sys_fields[i].default_value, example value is user
    is_null: if the field can be null or not, boolean. For Example: sys_fields[i].is_null, example value is false
    is_primary_key: if the field is primary key, boolean. For Example: sys_fields[i].is_primary_key, example value is false.
  8. sys_tables: all table’s name in current database.

Predefined Functions:

  1. print(str). Print the code without new line.
  2. println(str). Print the code with new line.
  3. getFieldList(). Return field list separated by ‘,’
  4. And a few other javascript functions, like capitalize, lowercase, uppercase, trim, etc. which you can add your own by Tools/Edit public functions

Steps to use this program:

  1. Create a project
  2. Add folder(s) and templates, template is written in JavaScript, and the only difference is it need the following format: <$ you code$> or <%=expression%>
  3. Generate files for multiple tables and templates(folders)

DB Connection Setting

Steps to config the database:

  1. Select Database Type. Click next.
  2. Input required information like host, port, username, password and database name depends on your database type.

Generate Files

Generate current file, Template/Generate current file

Generate project files, Project/Generate Project Files

Batch Generate, Project/Batch Generate, and then select tables and templates(folders) to generate files


  1. use JavaScript map instead of if … else …
        var type_defaultvalue={
        'datetime':'new Date()',
        for (var i=0; i<sys_fields.length; i++){
            var type = sys_fields[i].type;
                println("Undefined default value for field type: '" + type + "'");
            //the following line has the same result
            //println(sys_table_name + ".set" + formatFieldName(sys_fields[i].name) + "(" + type_defaultvalue[type] + ");");
            <%=sys_table_name%>.set<%=formatFieldName(sys_fields[i].name)%>(<%=type_defaultvalue[type] %>);
  2. write JavaScript function for project in project properties, and call them to put different tables in different place, e.g.
    function getModule(tablename){
            return "user/";
        //code to return other module name
        return "";

    and set the destination path for folder or template using this function: <%=getModule(sys_table_name)%><%=getDomainByTable(sys_table_name)%>, then if the current table is user, the destination path will be: user/, and if the table is log, then the destination page will be:

Improve this program:

Please write to me if:

  1. You need other type db connection or you wrote another db plugin
  2. You don’t know how to use it
  3. If you found any bug(s)
  4. Any suggestion and anything else…


Hope it’s useful for you. And hope it will decrease your time of copy & paste.

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