WAsys_Java_type_util

Common type-level utils for Java

Revision History

Latest: v0.2.3 (Nov 8, 2020)
Please refer to release_note.md file

Requirements

• Java 1.5 or later

Overview

This lib has module(s) about java type level funtionalities.
Each modules would cover a specific requirements/functionalities.

Installation

Artifacts could be grabed from central maven(or build by maven), and or ant.

Maven (source/bin format: 1.5)

<dependency>
    <groupId>com.github.911992</groupId>
    <artifactId>WAsys_Java_type_util</artifactId>
    <version>0.2.3</version>
</dependency>

Or you would clone the repo, and build it as following:

mvn clean package

Artifact under target folder

Ant (source/bin format: jdk 1.6)
Clone this repo, and build it by ant as following

ant clean jar

Artifact under dist folder

Module::Type Signature

Diagram 0: Type Signature Module Media Img

Abstract

This module is about parsing and generate a siganture of a type. The signature would have list of fields signature that includes the Field ptr, and its setter/getter methods.

Use Case

Serializing POJO were the main reason behind this. A requirement about auto data binding(read/write) like JDBC(thinking an ORM lib), or JSON.

Class Diagram

Diagram 1: Type Signature Module Class Diagram

Sample Usage

Considering following sample usages. Since using this lib is pretty simple and straight forward, so having a dedicated repo may not be very logical.

Simple Field Setting(no setter method)

class Entity0{
int model;
}
/*...*/
public static void main(String args[]) {
    //or Type_Signature<Entity0> _ts0=...
    Type_Signature _ts0=Type_Parser.parse_no_filter(Entity0.class, Type_Signature_Parse_Policy.DEFAULT_POLICY);
    Entity0 _e0=new Entity0();
    Type_Field_Signature _fage= _ts0.get_field_by_name("model");
    _fage.set(_e0, 911);
    System.out.printf("Model: %d\n",_e0.model);//911
}

Simple Field Setting(using setter method)

package java_type_util_test;
class Entity1{
public String name;
    public String getName() {
        return name;
    }
    public void setName(String arg_name) {
        System.out.printf("Setting name to:%s\n",arg_name);
        this.name = arg_name;
    }
}
/*...*/
public static void main(String args[]) {
    //or Type_Signature<?> _ts0=...
    Type_Signature _ts0=Type_Parser.parse_no_filter(Class.forName("java_type_util_test.Entity1"), new Type_Signature_Parse_Policy(Type_Signature_Parse_Policy.ACCESS_SPECIFIER_ALL, false/*include transient*/, false/*include static*/));
    Type_Field_Signature _fname = _ts0.get_field_by_name("name");
    /*Going to create a new object by default constructor, since there is no Object_Factory has associated*/
    /*Using a Object_Factory is HIGHLY recomended over default constructor!*/
    Object _obj0=_ts0.create_object();
     _fname.set(_obj0, "Porsche");//will call the setName()
}

List Of Scrabed Fields

class Entity2_P{
static String TYPE_VER;
String parent_name;
int parent_id;
}
class Entity2_C extends Entity2_P{
String child_name;
int child_id;
}
/*...*/
public static void main(String argsp[]) {
    //or Type_Signature<?> _ts =...
    Type_Signature<Entity2_C> _ts = Type_Parser.parse_no_filter(Entity2_C.class, new Type_Signature_Parse_Policy(Type_Signature_Parse_Policy.ACCESS_SPECIFIER_ALL, false/*excluding transient fields*/, true/*including static fields*/, Field_Definition_Order.From_Parent_To_Child/*scrap parent fields too*/));
    for(Type_Field_Signature _tfs : _ts.getProceed_fields()){
        System.out.printf("Field name:%s\n",_tfs.getField().getName());
    }
    /*out:
    Field name:TYPE_VER
    Field name:parent_name
    Field name:parent_id
    Field name:child_name
    Field name:child_id
    */
}

Using Generic_Object_Factory

class Plain_POJO3{
    public void hi(){
        System.out.println("Hello! Nothing especial here...");
    }
    public Plain_POJO3() {
        System.out.println("Instancing...");
    }
}
 /*...*/
 public static void main(String[] args) {
    try {
        //or Generic_Object_Factory<Plain_POJO3> _entity_factory = Generic_Object_Factory.new_instance(Plain_POJO3.class);
        Generic_Object_Factory<Plain_POJO3> _entity_factory = new Generic_Object_Factory<>(Plain_POJO3.class);
        Plain_POJO3 _smp = _entity_factory.create_object();//"Instancing..."
        _smp.hi();//"Hello! Nothing especial here..."
    } catch (Exception wth) {
        wth.printStackTrace();
    }   
}

Custom Getter And Setter Methods And Skipping Fields For Parsing

Since version 0.2.1, specifying a custom getter/setter method for a field is possible by annotating the target field using Field_Info annotation.

Annotation Skip_This_Field was removed on version 0.2.1, and now Field_Info.skip_this_field could be used instead. Any field marked as skip_this_field will be skipped in type processing stage.

class Student{
    
    @Field_Info(skip_this_field = true)
    private int not_a_field;
    
    @Field_Info(getter_method = "get_the_name",setter_method = "set_name")
    private String name;
    
    @Field_Info(setter_method = "set_age_please")
    private int age;

    public String get_the_name() {
        return name;
    }

    public void set_name(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void set_age_please(int age) {
        this.age = age;
    }
}
/*....*/
public static void main(String[] args) {        
    Type_Signature ts = Type_Parser.parse_no_filter(Student.class, Type_Signature_Parse_Policy.DEFAULT_POLICY);
    printout_fields(ts);
}
public static void printout_fields(Type_Signature<?> arg_typ_sig){
    for(Type_Field_Signature _tfs_ins : arg_typ_sig.getProceed_fields()){
        System.out.printf("field: %s , getter:%s, setter:%s\n",_tfs_ins.getField().getName(),_tfs_ins.getGetter_func(),_tfs_ins.getSetter_func());
    }
}
/*
Result:
field: name , getter:public java.lang.String type_util_lib_test.Student.get_the_name(), setter:public void type_util_lib_test.Student.set_name(java.lang.String)
field: age , getter:public int type_util_lib_test.Student.getAge(), setter:public void type_util_lib_test.Student.set_age_please(int)
*/

Dedicated isAaa For Boolean Types

Since version 0.2.1, boolean(also Boolean) types could cause the default parser to search for isAaa getetr method scheme instead of getAaa when it's absent.

class My_Entity{
    private boolean valid_state;

    public boolean isValid_state() {
        return valid_state;
    }

    public void setValid_state(boolean valid_state) {
        this.valid_state = valid_state;
    }
}
/*...*/
public static void main(String[] args) {
    Type_Signature<My_Entity> _tsig = Type_Parser.parse_no_filter(My_Entity.class, Type_Signature_Parse_Policy.DEFAULT_POLICY);
    for(Type_Field_Signature _tfs_ins : _tsig.getProceed_fields()){
        System.out.printf("field: %s , getter:%s, setter:%s\n",_tfs_ins.getField().getName(),_tfs_ins.getGetter_func(),_tfs_ins.getSetter_func());
    } 
}
/*
Result:
field: valid_state , getter:public boolean type_util_lib_test.My_Entity.isValid_state(), setter:public void type_util_lib_test.My_Entity.setValid_state(boolean)
*/