The Design and Application of Knowledge Learning System of

Criminal Procedure Law Based on NODE.JS

Miao Zhong

and Qian Xu

Sichuan Judicial and Police Officers Peofessional College, Deyang, Sichuan 618000, China

Keywords: Node.Js, Express, Development, Study of Criminal Procedure Law.

Abstract: This paper has carried out related research on the development of knowledge learning application system of

criminal procedure law. The server side of the system breaks the tradition, chooses Node.js for

development, and combines the express framework engine and related components to use JavaScript to

realize the functions of file transfer and URL routing of the system. Then the front-end uses

HTML5+CSS3+JavaScript language and Bootstrap framework to develop a responsive dynamic page that

displays data in the browser. The system developed based on Node.js has the advantages of low R&D cost,

easy expansion and high reusability. On the basis of teaching the basic concepts and theories of criminal

procedure in the form of video media, the function of the knowledge learning system of criminal procedure

law also focuses on the various procedures of criminal procedure. In the form of video cases, the knowledge

system of criminal procedure law is displayed intuitively for students, which lays a solid foundation for

cultivating high-quality legal professionals.

https://orcid.org/0000-0003-2270-0166

https://orcid.org/0000-0003-4064-9632

1 INTRODUCTION

The criminal procedure is one of the key compulsory

courses in the law discipline of colleges and

universities in China. And colleges and universities

are the important positions of law education in our

country. The educators of law disciplines should

undertake the important mission of promoting the

legal system construction in our country. Therefore,

we should constantly push forward the process of

optimizing and reforming the course of criminal

procedure law. However, there are many

shortcomings in the current course of criminal

procedure law education. First of all, most teachers'

teaching is based on unchangeable textbooks, which

is easy to be divorced from reality, and case teaching

is insufficient. Besides, teachers are the main body

in teaching, and students passively accept it, so it is

difficult to learn according to students' own

situation. The teaching content of criminal procedure

is more complicated than other subjects, and it is

difficult for a single book teaching to present all the

key contents. (Liu, 2022)

According to the above analysis, the author of

this paper believes that the teaching form of criminal

procedure law should be reformed and optimized

digitally with the help of information technology in

the current Internet era. So, this paper studies the

knowledge learning system of criminal procedure

law based on Node.js. This systematic course takes

criminal litigation activities as the research object,

expounds the basic principles, basic systems, basic

procedures and legal basis of criminal litigation,

probes into the historical development and practical

exploration of China's criminal procedure law,

especially systematically combs the Marxist view of

criminal procedure law. The theoretical teaching of

this course includes six teaching modules: basic

theory, litigation system, pretrial procedure, trial

procedure, execution procedure and special

procedure. Through the study of various courses in

this system, students can comprehensively and

systematically grasp the basic concepts, basic

theories and specific contents of criminal

proceedings, establish the concept of procedural rule

of law, and improve their awareness of human rights

protection. They are not only familiar with the legal

Zhong, M. and Xu, Q.

The Design and Application of Knowledge Learning System of Criminal Procedure Law Based on NODE.JS.

DOI: 10.5220/0011898500003613

In Proceedings of the 2nd International Conference on New Media Development and Modernized Education (NMDME 2022), pages 73-77

ISBN: 978-989-758-630-9

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

provisions of criminal proceedings, but also have the

ability to analyze and solve criminal proceedings,

and can master the basic skills of public security

organs in filing, investigating and using evidence to

try criminal cases, so as to meet the needs of public

security practice in the future.

2 KEY TECHNOLOGIES

2.1 Node.Js

The Node.js is an open source and high performance

runtime environment package based on JavaScript.

Besides enabling JavaScript code to be implemented

on the browser client, Node.js can also run on the

back-end server, and even realize functions such as

communication and file processing. Because of the

emergence of Node.js, JavaScript has become the

full-stack development language of applications

from front-end development scripts, and compared

with the traditional development methods, the built

applications of Node.js respond faster and are easier

to expand. The Node.js can not only request multiple

data sources at the same time, but also customize

different servers for the same data source, which has

high flexibility. In this paper, the back-end design of

the system is carried out by using the characteristics

of single thread, asynchronous non-blocking I/O and

event-driven of Node.js. (Wang, 2015)

2.2 Express Framework

The Expresss is a web application software

development tool framework developed based on

Node.js described above. With the advantage of

Express Node.js, it is also favored by developers,

because it has the advantages of rapid development,

flexible expansion and quick use. The powerful

functions of express include stable routing, dynamic

view helper and redirection helper. Among them, the

Node.js package manager, also known as NPM, can

keep express in the dependency list and develop the

basic template of Express by inputting only one line

of commands without requiring developers to input

too many codes. After the development of the basic

template, you can quickly add other functions to

build a complete application composed of Node.js

server through a quick expansion mechanism. The

main feature of express is that it simplifies the

processing of HTTP request parameters and has a

middleware mechanism to effectively control these

HTTP request parameters. It also maintains the

function of dynamically rendering front-end HTML

and supporting template engine that Node.js has.

(Zhang, 2018)

2.3 NoSQL Database Mongodb

NoSQL database refers to a non-relational database,

and there is no relationship between the stored data,

which will be more conducive to expansion and

more flexible. Mongodb is a typical nosql database

with high concurrency, which can be used to meet

the writing requirements of high-traffic data.

Besides, mongodb is a flexible and independent

distributed database, which stores data in different

hosts. Mongodb is also a document database. In a

common database, the basic unit of our operation is

JSON (JavaScript Object Notation), while the basic

unit of mongodb's operation is BSON strengthened

on the basis of JSON, which uses document to

organize and store data. (Zhu, 2019)

There are many similarities between Mongodb

and traditional relational databases such as mysql,

especially in data organization. The difference is that

each database on mongodb server stores collection,

while mysql is table. The record form of collection

is displayed as document, and each document is

separated and independent. Because it is a non-

relational database, the coding step of declaring the

field type is omitted, and the same field is not

required to be the same type at the same time. The

differences between Mongodb and mysql are shown

in Table 1.

Table 1 Differences between mongodb and MySQL

MongoDB MySQL

Database Database

Collection Table

Document Row

Field column

2.4 Development Environment

The knowledge learning system of criminal

procedure law is developed by separating the front

and back ends. The system chooses Linux CentOS7

version. The front-end design mainly uses

HTML5+CSS3+JavaScript language, and uses

Bootstrap framework to develop a responsive

dynamic page that displays data in the browser. In

the back-end server development of the application

system, JavaScript language is used for

development, and Node.js is used as the

environment package. And the scripting language

NMDME 2022 - The International Conference on New Media Development and Modernized Education

writing tool of Node.js uses Visual Studio

Code2019. Nginx load balancer can be used to

ensure the rapid response of the server. The server

adopts the relational database MySQL version

8.0.28. On the choice of the server, the mixed

database of mysql and mongodb is adopted. Mysql

can store relational data, such as the relationship

data between students and teachers, and the user

information and permission level that the system

needs to set. (Wang, 2018) The non-relational

database mongodb is used to store some more

substantial large files, pictures, videos and other

types of resources. When building a database server,

after the driver package of each database is installed,

it is necessary to use the normalization of tables as

much as possible to achieve the purpose of reducing

data redundancy and various abnormal situations of

data operation. Of course, there will be cases of

choosing the anti-normal table, such as some cases

where the query efficiency needs to be specially

optimized. In this system, the anti-normal table is

used to realize the structured data operation function

between teachers and students. However, when

deploying mongodb database server, when setting

keywords, it is necessary to avoid using _id keyword

to accurately query the required content in order to

make the query result error due to the same

attributes of name, title and day. Through the

introduction of the above key technologies, we have

determined the overall environment for the

development of the knowledge learning system of

criminal procedure law, the configuration of related

software and tools, and the technical feasibility of

the overall project.

3 PROCESSREQUIREMENT

ANALYSIS

3.1 Functional Requirements

Considering the different needs of different user

groups, the knowledge learning system of criminal

procedure law develops two types of user ports:

teacher's port and user's port. Students' clients are

required to record students' learning situation at all

stages, and they also need to have the function of

academic communication and interaction with

teachers. The most important thing is that they can

supplement their knowledge of criminal procedure

law through online video courses. The characteristic

function of the system is to simulate the trial

function, and different student users can participate

in online interaction at the same time to deepen their

knowledge and understanding of criminal

proceedings. (Chang, 2021)

The main function of teachers' users is to select

resources or make teaching resources, and submit

teaching documents in the form of external links or

uploading documents. Secondly, according to the

completion of homework and the types of academic

problems submitted by students, teachers give

corresponding guidance and suggestions, so check

the effect of online teaching and the overall learning

situation. In setting the teaching content of the

course of Criminal Procedure Law, teachers should

highlight the foundation that is easy for students to

accept, the practicality that is conducive to students'

follow-up application, and the frontier of future

discipline development. It is necessary to

systematically ensure that during online classroom

teaching by teachers, students can grasp the

principles, systems and procedures of criminal

procedure in time, and at the same time, they should

keep up with the pace of the times and accurately

grasp the latest situation of procedural law. Teachers

can update the course content at any time, so that

case teaching can keep up with current events and

maximize practicality.

3.2 Overall Design

This system is designed based on B/S architecture,

and adopts MVC mode, which divides the system

into control layer, template layer and view layer for

separate design. The system consists of three layers:

display layer, business logic layer and data access

layer. The display layer is the interface between

teachers and students, users and application systems.

It can achieve man-machine interaction between

users and computers, show teaching courses, and

display pages of various functional operations. The

business logic layer is responsible for processing the

data of teachers and students and the logic operation

of business functions, including course resource

management, user information management and

statistical analysis of students' learning situation.

The data access layer is used to realize the related

functions of querying, adding, modifying and

deleting data information of the system.

The model layer uses Modelproxy, the control

layer uses Express, and the view layer depends on

Handlebars. After the overall preliminary structure is

established, you can start to configure package.json

to unify the data language, and then execute npm

install, and the system will automatically install the

corresponding dependency packages. When all the

The Design and Application of Knowledge Learning System of Criminal Procedure Law Based on NODE.JS

projects are configured, execute the command npm

start to start the back-end service. The routing

function of the system is controlled by router.js The

middleware of HTTP request parameters can

provide interfaces to receive and forward all kinds of

user requests, so as to realize the function of

business processing. After the business logic module

completes the operation task, the router module

packages HTTP response packets and forwards them

to the browser client to realize the request execution

process. The server function of the system is realized

based on Node.js and mysql in intranet. The key

code of Node.js connecting to MySQL's database

server is shown in Figure 1.

Figure 1: Code of Node.js connecting mysql server

4 FUNCTION REALIZATION

4.1 Teacher Side

After the teacher logs in to the system through the

employee number and the corresponding password,

he can see that the main functional modules of the

teacher are resource uploading, homework approval,

learning situation viewing and personal information.

The resources of students' learning courses,

extracurricular exploration and other functional

modules are designed and uploaded by teachers.

According to the teaching plan and syllabus,

teachers design the course content. Teachers can

quote high-quality online courses by quoting

external links, or they can make the same recording

by themselves. The teachers need to classify and

label the courses and manage the list of courses.

Manage the teacher's course list, click the button to

trigger the system's front-end method of

loadSubjectData to load the data of each resource.

During the loading process, the system accesses the

back-end interface of the system's back-end server

by way of post request through ajax to interact.

When the data information of the management page

is loaded, the function of teachers and users to add

courses is realized by the system post requesting

access and calling the insertSubject method. The

code of managing video courses is shown in Figure

2. The courses recorded and produced by teachers

themselves need to be entered systematically by

uploading files. The function of uploading files first

requires the foreground to call loadSubjectData to

load the established course data, and then calls

loadCoursewareData method to request ajax to

perform asynchronous interaction and access the

interface to establish the data connection between

the course data and video files. Then, through the

submitUpload method, send a request instruction to

the background uploadCourseware interface to

complete the upload of video file resources.

Figure 2: Management course function code

implementation

4.2 Student Side

After logging in to the system through the account,

students can see four modules: study course,

extracurricular exploration, homework submission

and personal information. The learning course

module is the main course designed according to the

syllabus. Theoretical teaching includes six teaching

modules: basic theory, litigation system, pre-trial

procedure, trial procedure, execution procedure and

special procedure. When completing the content

study in each class, the system will automatically

jump to the homework submission page, and

students can check the homework notices issued in

each class to study the homework after class. The

extra-curricular exploration is to supplement extra-

curricular knowledge to the teaching of criminal

procedure law. The initial user information is

designed and entered when the school uniformly

registers the account. The user can make a second

modification. The core code of the creation

statement taking the user information table as an

example is shown in Figure 3. (Li, 2022)

NMDME 2022 - The International Conference on New Media Development and Modernized Education

Figure 3: User information table creation code

The main body of the teaching module of this

system is the video playing teaching module. This

function module is implemented in such a way that

users can watch videos stored and served online. The

developer uploads the video to the server in the way

of streaming, and the front-end player renders and

watches it. This system refers to the play online of

web player SDK technology provided by Aliplayer,

and only needs to introduce this part of SDK

configuration in the front-end code header file to

realize online viewing of teaching videos. When

students learn the relevant knowledge of trial of theft

cases in online learning videos, such as the concept

of theft cases, the constitution of crimes and the

corresponding criminal liability laws, and watch the

trial videos uploaded by teachers, they can click to

enter the mock trial in the extracurricular exploration

function module. When a teacher initiates a trial,

students can choose the corresponding roles of

investigators, criminal suspects, lawyers and

paralegals, and learn and be familiar with the

process of the first trial of a public prosecution case,

that is, court hearing, court investigation, court

debate, defendant's final statement, appraisal and

sentencing. During this period, students can have a

more intuitive feeling about the process of criminal

proceedings, and can further grasp the corresponding

rights and obligations of all parties involved.

5 CONCLUSIONS

In order to show the knowledge of criminal

procedure in various forms, realize the efficient use

of rich online resources and improve the interest of

law students in criminal procedure knowledge, this

paper designs a knowledge learning system of

criminal procedure law based on NODE. JS, which

provides an internet-based knowledge learning

platform. The back-end system of the system adopts

Node.js combined with Express framework to

realize the function of JSON data interaction. At

last, through the system test, the system can run

normally, providing a new back-end solution for the

construction of online learning applications. Due to

my limited research time, environment and ability,

there are many shortcomings in this system, which

need the help of relevant personnel to improve it.

For example, the number of servers in the system is

limited, and when as many as 100 users jointly issue

instructions, the concurrency of the system is

insufficient. At the same time, this paper only

studies the PC system, but not other devices, so it is

difficult to provide more convenient and fast

services. Subsequent improvements can be made,

mobile services with a wider audience can be

designed, and data interoperability of port-like

platforms can be realized to make the services of the

platform more perfect.

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The Design and Application of Knowledge Learning System of Criminal Procedure Law Based on NODE.JS